0001193125-26-056502 | 10-K | XBRL Viewer

Print Document

Leases - Maturities of Lease Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Lessee, Operating Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract]
Within one year	$ 16.3	$ 14.3
Year two	10.0	9.8
Year three	8.1	5.7
Year four	6.4	5.1
Year five	4.9	3.9
Thereafter	15.3	11.7
Total lease payments	61.0	50.5
Less imputed interest	(8.3)	(5.6)
Total operating lease liabilities	$ 52.7	$ 44.9

Share-Based Compensation Plans

12 Months Ended

Dec. 31, 2025

Share-Based Payment Arrangement [Abstract]

Share-Based Compensation Plans

Note 18. Share-Based Compensation Plans

Stock option plans

The Company has two stock option plans, the Omnibus Long-Term Incentive Plan and the ShareSave Plan 2008 under which it currently grants awards. Innospec's ShareSave plan is an employee stock purchase plan, or ESPP.

The stock options have vesting periods ranging from 2 to 5 years and in all cases stock options granted expire within 10 years of the date of grant. All grants are at the sole discretion of the Compensation Committee of the Board of Directors. Grants may be priced at market value or at a premium or discount. The aggregate number of shares of common stock reserved for issuance which can be granted under the plans is 2,550,000.

The fair value of stock options is measured on the grant date using either a fair market value methodology, or in cases where performance criteria are dependent upon external factors such as the Company’s stock price, using a Monte Carlo model.

The Company’s policy is to issue shares from treasury stock to holders of stock options who exercise those options, but if sufficient treasury stock is not available, the Company will issue previously unissued shares of stock to holders of stock options who exercise options.

Stock equivalent units

The Company awards Stock Equivalent Units (“SEUs”) from time to time as a long-term performance incentive. SEUs are cash settled equity instruments conditional on certain performance criteria and the fair value is linked to the Innospec Inc. share price. SEUs have vesting periods ranging from six months to 5 years and in all cases SEUs granted expire within 10 years of the date of grant. Grants may be priced at market value or at a premium or discount. There is no limit to the number of SEUs that can be granted. As at December 31, 2025 the liability for SEUs of $12.5 million is included in accrued liabilities in the consolidated balance sheet, where they will remain until they are cash settled.

The fair value of SEUs is re-measured at each balance sheet reporting date using either a fair market value methodology, or in cases where performance criteria are dependent upon external factors such as the Company’s stock price, using a Monte Carlo model.

Compensation cost

The compensation cost recorded for stock options was $8.1 million, $8.5 million and $8.0 million for 2025, 2024 and 2023, respectively. The compensation cost for stock options is based on the grant-date fair value and spread evenly over the vesting period.

The compensation cost recorded for SEUs was $1.8 million, $6.5 million and $13.5 million for 2025, 2024 and 2023, respectively. The compensation cost for SEUs is spread over the life of the award subject to a revaluation to the fair value at each quarter end. The revaluation may result in a charge or a credit to the income statement in each quarter dependent upon our share price movements and other performance criteria.

Forfeits are accounted for as an adjustment to the charge in the period in which the forfeits occur.

Transactions in the period

The fair value of each stock option or SEU granted in the year was calculated with the following weighted average assumptions to determine the grant-date fair values of the share-based compensation:


	2025			2024			2023
Dividend yield		1.51	%		1.13	%		1.16	%
Expected life	3 years			3 years			4 years
Volatility		27.0	%		25.5	%		39.7	%
Risk free interest rate		4.16	%		4.38	%		4.47	%

The dividend yield was based on our recent history of dividend payouts. The expected life was determined based upon historical exercise experience. The volatility was determined based upon the historical daily stock price volatilities. The risk free interest rate was based on the U.S. Federal Reserve 3 year interest rate at the grant dates, which approximates to the expected term of the options.

The following tables summarizes the transactions of the Company’s share-based compensation plans for the year ended December 31, 2025.


	Number of shares			Weighted Average Grant-Date Fair Value
Nonvested at December 31, 2024		574,671		$	86.2
Granted		166,337		$	107.1
Vested		(210,227	)	$	77.8
Forfeited		(11,831	)	$	72.5
Cancelled		(87,653	)	$	31.3
Nonvested at December 31, 2025		431,297		$	109.5


	Number of shares			Weighted Average Exercise price		Weighted-Average Remaining Contractual Term (years)
Outstanding at December 31, 2024		619,705		$	23.5
Granted		166,337		$	—
Exercised		(139,904	)	$	3.5
Forfeited		(17,281	)	$	34.0
Cancelled		(87,653	)	$	75.7
Outstanding at December 31, 2025		541,204		$	12.7		2.1
Exercisable at December 31, 2025		109,907		$	49.1		2.7

For the awards granted with market conditions, a Monte Carlo model has been used to calculate the grant-date fair value. For all other awards granted, a fair market value methodology has been used to calculate the grant-date fair value.

The awards granted with market and non-market conditions include performance measures that can result

in a maximum 200% vesting for the number of stock options granted. The predicted vesting has been reflected in the grant-date fair value calculation, but has not been reflected for the number of awards granted, as shown in the table above.

Other disclosures

As at December 31, 2025, there was $17.7 million of total unrecognized compensation cost related to nonvested share-based compensation arrangements. That cost is expected to be recognized over a weighted-average period of 1.8 years.

The total intrinsic value of share-based compensation plans outstanding at December 31, 2025 was $34.4 million. The total intrinsic value of share-based compensation plans exercisable at December 31, 2025 was $3.0 million. The total intrinsic value of share-based compensation plans exercised, was approximately $13.5 million in 2025 and $22.4 million in 2024.

The total cash paid for SEUs exercised was approximately $6.2 million in 2025 and $12.8 million in 2024. The total fair value of share-based compensation that vested was $16.4 million in 2025 and $16.4 million in 2024.

The weighted-average grant-date fair value of share-based compensation plans granted during 2025, 2024, and 2023 was $107.1, $130.3, and $94.4, respectively.

The Company recorded a current tax charge of $1.0 million in 2025, a current tax charge of $0.1 million in 2024 and a current tax charge of $0.3 million in 2023, in relation to stock option compensation. This amount is inclusive of excess tax benefits.

Nature of Operations	12 Months Ended
Dec. 31, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations	Note 1. Nature of Operations Innospec develops, manufactures, blends, markets and supplies a wide range of specialty chemicals to markets in the Americas, Europe, the Middle East, Africa and Asia-Pacific. Our Performance Chemicals business creates innovative technology-based solutions for our customers in the personal care, home care, agrochemical, construction, mining and other industrial markets. Our Fuel Specialties business specializes in manufacturing and supplying fuel additives that improve fuel efficiency, boost engine performance and reduce harmful emissions. Our Oilfield Services business supplies chemicals for drilling, completion, production and DRA which make exploration and production more effective, cost-efficient and environmentally friendly.

Nature of Operations

12 Months Ended

Dec. 31, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Nature of Operations

Note 1. Nature of Operations

Innospec develops, manufactures, blends, markets and supplies a wide range of specialty chemicals to markets in the Americas, Europe, the Middle East, Africa and Asia-Pacific. Our Performance Chemicals business creates innovative technology-based solutions for our customers in the personal care, home care, agrochemical, construction, mining and other industrial markets. Our Fuel Specialties business specializes in manufacturing and supplying fuel additives that improve fuel efficiency, boost engine performance and reduce harmful emissions. Our Oilfield Services business supplies chemicals for drilling, completion, production and DRA which make exploration and production more effective, cost-efficient and environmentally friendly.

Property, Plant and Equipment - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Amounts of assets held under finance leases	$ 286.1	$ 269.7
Depreciation charges	32.1	31.0	$ 27.9
Impairment of property, plant and equipment	22.9	0.0	$ 0.0
Assets Held under Capital Leases [Member]
Property, Plant and Equipment [Line Items]
Amounts of assets held under finance leases	$ 0.0	$ 0.0

Cover Page - USD ($) $ in Millions	12 Months Ended
Cover Page - USD ($) $ in Millions	Dec. 31, 2025	Jan. 31, 2026	Jun. 30, 2025
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	FY
Document Annual Report	true
Document Transition Report	false
Current Fiscal Year End Date	--12-31
Document Period End Date	Dec. 31, 2025
Entity File Number	1-13879
Entity Registrant Name	INNOSPEC INC.
Entity Central Index Key	0001054905
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	98-0181725
Entity Address, Postal Zip Code	80112
City Area Code	303
Local Phone Number	792 5554
Security Exchange Name	NASDAQ
Title of 12(b) Security	Common stock
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		24,777,859
Entity Address, Address Line One	8310 South Valley Highway
Entity Address, Address Line Two	Suite 350
Entity Address, City or Town	Englewood
Entity Address, State or Province	CO
Trading Symbol	IOSP
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	Yes
Entity Public Float			$ 1,289
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Portions of Innospec Inc.’s Proxy Statement for the Annual Meeting of Stockholders to be held on May 8, 2026 are incorporated by reference into Part III of this Form 10-K.
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Auditor Name	PricewaterhouseCoopers LLP
Auditor Firm ID	876
Auditor Location	Manchester, United Kingdom
Auditor Opinion [Text Block]	Opinions on the Financial Statements and Internal Control over Financial Reporting We have audited the accompanying consolidated balance sheets of Innospec Inc. and its subsidiaries (the “Company”) as of December 31, 2025 and 2024, and the related consolidated statements of income, comprehensive income, equity and cash flows for each of the three years in the period ended December 31, 2025, including the related notes (collectively referred to as the “consolidated financial statements”). We also have audited the Company's internal control over financial reporting as of December 31, 2025, based on criteria established in Internal Control - Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). In our opinion, the consolidated financial statements referred to above present fairly, in all material respects, the financial position of the Company as of December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2025 in conformity with accounting principles generally accepted in the United States of America. Also in our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2025, based on criteria established in Internal Control - Integrated Framework (2013) issued by the COSO.

Fair Value Measurements - Carrying Amount and Fair Values of the Company's Assets and Liabilities Measured on a Recurring Basis (Detail) - Recurring [Member] - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Carrying Amount [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Emission Trading Scheme Credits [Member]
Derivatives (Level 1 measurement):
Derivatives asset	$ 3.2	$ 3.9
Carrying Amount [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Foreign Currency Forward Exchange Contracts [Member]
Derivatives (Level 1 measurement):
Derivatives asset	3.4	1.5
Carrying Amount [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Non-financial liabilities (Level 3 measurement):
Acquisition-related contingent consideration	8.3	20.1
Fair Value [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Emission Trading Scheme Credits [Member]
Derivatives (Level 1 measurement):
Derivatives asset	3.2	3.9
Fair Value [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Foreign Currency Forward Exchange Contracts [Member]
Derivatives (Level 1 measurement):
Derivatives asset	3.4	1.5
Fair Value [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Non-financial liabilities (Level 3 measurement):
Acquisition-related contingent consideration	$ 8.3	$ 20.1

Long-Term Debt (Tables)

12 Months Ended

Dec. 31, 2025

Debt Disclosure [Abstract]

Summary of Debt Refinancing Costs

The deferred finance costs of $0.7 million (December 31, 2024 – $1.1 million) related to the arrangement of the credit facility, are included within other current and non-current assets at the balance sheet dates.


(in millions)	2025			2024
Gross cost at January 1	$	1.7		$	1.4
Capitalized in the year		—			0.3
		1.7			1.7

Accumulated amortization at January 1	$	(0.6	)	$	(0.2	)
Amortization in the year		(0.4	)		(0.4	)
	$	(1.0	)	$	(0.6	)

Net book value at December 31	$	0.7		$	1.1

Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Detail) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	$ 712.2	$ 612.0
Less accumulated depreciation and impairment	(426.1)	(342.3)
Property, plant and equipment, Net	286.1	269.7
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	23.6	21.6
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	109.7	88.7
Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	508.9	439.6
Work in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	$ 70.0	$ 62.1

Income Taxes - Roll-forward of Unrecognized Tax Benefits and Associated Accrued Interest and Penalties (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Tax Contingency [Line Items]
Opening balance at January 1	$ 0	$ 14,800,000	$ 13,400,000
Reductions for tax positions of prior periods	0	(15,600,000)	0
Additions for tax positions of prior periods	0	800,000	1,400,000
Closing balance at December 31	0	0	14,800,000
Current	0	0	(1,200,000)
Non-current	0	0	13,600,000
Unrecognized Tax Benefits [Member]
Income Tax Contingency [Line Items]
Opening balance at January 1	0	10,500,000	10,200,000
Reductions for tax positions of prior periods	0	(10,500,000)	0
Additions for tax positions of prior periods	0	0	300,000
Closing balance at December 31	0	0	10,500,000
Current	0	0	(1,000,000)
Non-current	0	0	9,500,000
Interest and Penalties [Member]
Income Tax Contingency [Line Items]
Opening balance at January 1	0	4,300,000	3,200,000
Reductions for tax positions of prior periods		(5,100,000)	0
Additions for tax positions of prior periods		800,000	1,100,000
Closing balance at December 31	0	0	4,300,000
Current	0	0	(200,000)
Non-current	$ 0	$ 0	$ 4,100,000

Goodwill - Additional Information (Detail) - USD ($)	6 Months Ended	12 Months Ended
Goodwill - Additional Information (Detail) - USD ($)	Jun. 30, 2024	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Jul. 31, 2025
Goodwill [Line Items]
Additional goodwill		$ 2,000,000
Increase in fair vlue of net assets			$ (3,100,000)
Goodwill		399,000,000	382,500,000	$ 399,300,000	$ 2,000,000
Fuel Specialties [Member]
Goodwill [Line Items]
Additional goodwill		0
Increase in fair vlue of net assets			0
Impairment of goodwill		0	0	0
Goodwill		207,700,000	207,500,000	207,600,000
Performance Chemicals [Member]
Goodwill [Line Items]
Additional goodwill		0
Increase in fair vlue of net assets			(3,100,000)
Impairment of goodwill		0	0	0
Goodwill		144,500,000	130,100,000	146,900,000
Oilfield Services [Member]
Goodwill [Line Items]
Additional goodwill		2,000,000
Increase in fair vlue of net assets			0
Impairment of goodwill		0	0	0
Goodwill		$ 46,800,000	$ 44,900,000	44,800,000
QGP Quimica Geral [Member]
Goodwill [Line Items]
Additional goodwill				$ 37,400,000
Increase in fair vlue of net assets	$ 3,100,000

- Definition

Amount, after accumulated impairment loss, of asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 24
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482548/350-20-55-24

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-8

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 41
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479303/805-10-55-41

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 740
-Name Accounting Standards Codification
-Section 55
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478064/805-740-55-13

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 39
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479303/805-10-55-39

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 49
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482785/280-10-55-49

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 100
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-100

Reference 8: http://www.xbrl.org/2003/role/exampleRef
-Topic 852
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481372/852-10-55-10

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(15))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482598/350-20-45-1

Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 12: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(10)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 14: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-4

+ Details

- Definition

Amount of impairment loss from asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

+ References + Details

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 24
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482548/350-20-55-24

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1A

+ Details

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2025

Dec. 31, 2024

Income Tax Disclosure [Abstract]

Sources of Income before Income Taxes

The sources of income before income taxes were as follows:


(in millions)	2025		2024			2023
Domestic	$	25.9	$	90.2		$	95.2
Foreign		112.2		(49.0	)		79.2
	$	138.1	$	41.2		$	174.4

Components of Income Tax Expense

The components of income tax expense are summarized as follows:


(in millions)	2025			2024			2023
Current:
Federal	$	4.5		$	16.9		$	12.4
State and local		1.7			2.9			0.2
Foreign		24.3			26.2			18.6
		30.5			46.0			31.2
Deferred:
Federal		(7.7	)		(4.1	)		5.2
State and local		(0.3	)		(0.5	)		0.3
Foreign		(1.0	)		(35.8	)		(1.4	)
		(9.0	)		(40.4	)		4.1
Total:
Federal		(3.2	)		12.8			17.6
State and local		1.4			2.4			0.5
Foreign		23.3			(9.6	)		17.2
	$	21.5		$	5.6		$	35.3

Factors Effecting Effective Tax Rate from U.S. Federal Statutory Rate


(in millions)	2025						2024						2023
	in Dollars			in Percent			in Dollars			in Percent			in Dollars			in Percent
U.S. federal statutory tax rate	$	29.0			21.0	%	$	8.7			21.0	%	$	36.6			21.0	%
State and local income taxes, net of federal income tax effect*		1.7			1.2	%		2.7			6.6	%		1.0			0.6	%
Foreign tax effects:
Brazil:
Changes in valuation allowance	**			**				2.7			6.6	%	**			**
Adjustment to contingent consideration		(3.2	)		-2.3	%		0.7			1.7	%	**			**
Foreign tax rate differential	**			**			**			**				(1.8	)		-1.0	%
Other		(1.2	)		-0.8	%		0.8			1.9	%		0.3			0.2	%
Germany:
Foreign tax rate differential	**			**				0.7			1.7	%	**			**
Other	**			**				(0.1	)		-0.2	%	**			**
Italy	**			**				0.6			1.5	%	**			**
U.K.:
Foreign tax rate differential		2.1			1.5	%		(3.4	)		-8.3	%		1.3			0.7	%
Foreign currency transactions	**			**			**			**				(2.6	)		-1.5	%
Innovation incentives		(3.2	)		-2.3	%		(3.2	)		-7.8	%		(1.5	)		-0.9	%
Other		0.4			0.3	%		0.4			1.0	%		0.5			0.3	%
Other foreign jurisdictions		2.7			2.0	%		0.2			0.5	%		1.7			1.0	%
Effect of cross-border tax laws:
Global intangible low-taxed income, net of foreign tax credit		0.8			0.6	%		4.3			10.4	%		(0.2	)		-0.1	%
Subpart F income, net of foreign tax credit		—			0.0	%		1.2			2.9	%		0.2			0.1	%
Incentive for foreign derived intangible income		(0.5	)		-0.4	%		(1.9	)		-4.6	%		(4.5	)		-2.6	%
Tax on unremitted foreign earnings		2.1			1.5	%		0.8			1.9	%		2.4			1.4	%
Other		0.1			0.1	%		0.3			0.7	%		—			0.0	%
Tax credits		(0.5	)		-0.4	%		(0.9	)		-2.2	%		(1.0	)		-0.6	%
Nontaxable or nondeductible items:
Nondeductible officer compensation	**			**				2.0			4.9	%		1.8			1.0	%
Other		0.7			0.5	%		(0.9	)		-2.1	%		(0.2	)		-0.1	%
Changes in unrecognized tax benefits		—			0.0	%		(10.1	)		-24.5	%		1.3			0.7	%
Tax impact of internal reorganizations		(9.5	)		-6.9	%		—			0.0	%		—			0.0	%
	$	21.5			15.6	%	$	5.6			13.6	%	$	35.3			20.2	%

* State taxes in Texas, Louisiana and Oklahoma made up the majority (greater than 50%) of the tax effect in this category in 2025 (2024 and 2023: Texas, California and Oklahoma).

** The amount of income tax during the year does not meet the required threshold and is included in relevant 'Other' category.

Schedule of Cash Paid for Income Taxes (Net of Refunds)

Cash paid for income taxes (net of refunds) consisted of the following:


(in millions)	2025		2024		2023
Federal	$	26.1	$	27.5	$	27.5
State and local		3.1		1.4		4.7
Foreign:
Brazil		2.9		2.9	*
Canada	*			3.7	*
Germany		3.3		4.2		7.4
Italy		3.9		3.9	*
U.K.		6.8		6.7		8.6
Other Foreign		4.9		1.4		6.1
		21.8		22.8		22.1
	$	51.0	$	51.7	$	54.3

*The amount of income taxes paid during the year does not meet the required threshold and is included in 'Other Foreign'.

Details of Deferred Tax Assets and Liabilities

Details of deferred tax assets and liabilities are analyzed as follows:


(in millions)	2025			2024
Deferred tax assets:
Stock compensation	$	3.3		$	3.7
Net operating loss carry forwards		8.2			8.8
Other intangible assets		15.6			4.8
Accretion expense		3.2			3.2
Restructuring provision		1.4			1.5
Employee related liabilities		4.6			9.2
Foreign tax credits		3.0			2.1
Operating lease liabilities		12.9			11.1
Inventory provisions		9.4			9.0
Pensions		1.2			0.5
Carried forward interest deductions		2.7			1.4
Bad debt reserves		1.1			1.4
Research and experimental expenditure		6.1			8.3
Other		5.7			3.4
Subtotal		78.4			68.4
Less valuation allowance		(2.8	)		(2.4	)
Total net deferred tax assets	$	75.6		$	66.0
Deferred tax liabilities:
Property, plant and equipment	$	(27.0	)	$	(29.5	)
Intangible assets including goodwill		(31.2	)		(31.6	)
Customer relationships		(1.0	)		(1.7	)
Unremitted overseas earnings		(7.2	)		(5.1	)
Right-of-use assets		(12.9	)		(10.7	)
Other		(1.8	)		(1.5	)
Total deferred tax liabilities	$	(81.1	)	$	(80.1	)
Net deferred tax liability	$	(5.5	)	$	(14.1	)
Deferred tax assets	$	13.6		$	9.4
Deferred tax liabilities		(19.1	)		(23.5	)
	$	(5.5	)	$	(14.1	)

Roll-forward of Unrecognized Tax Benefits and Associated Accrued Interest and Penalties

A roll-forward of unrecognized tax benefits and associated accrued interest and penalties is as follows:


(in millions)	Unrecognized Tax Benefits			Interest and Penalties			Total
Opening balance at January 1, 2023	$	10.2		$	3.2		$	13.4
Reductions for tax positions of prior periods		—			—			—
Additions for tax positions of prior periods		0.3			1.1			1.4
Closing balance at December 31, 2023		10.5			4.3			14.8
Current		(1.0	)		(0.2	)		(1.2	)
Non-current	$	9.5		$	4.1		$	13.6
Opening balance at January 1, 2024	$	10.5		$	4.3		$	14.8
Reductions for tax positions of prior periods		(10.5	)		(5.1	)		(15.6	)
Additions for tax positions of prior periods		—			0.8			0.8
Closing balance at December 31, 2024		—			—			—
Current		—			—			—
Non-current	$	—		$	—		$	—
Opening balance at January 1, 2025	$	—		$	—		$	—
Reductions for tax positions of prior periods		—						—
Additions for tax positions of prior periods		—						—
Closing balance at December 31, 2025		—			—			—
Current		—			—			—
Non-current	$	—		$	—		$	—

Other Intangible Assets - Summary of Other Intangible Assets (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Gross cost at January 1	$ 331.9	$ 315.1
Additions	23.6	24.3
Exchange effect	17.8	(7.5)
Gross cost at December 31	373.3	331.9	$ 315.1
Accumulated amortization at January 1	(266.5)	(257.8)
Amortization expense	(11.6)	(12.6)	(10.6)
Impairment	(19.0)	0.0
Exchange effect	(8.5)	3.9
Accumulated amortization at December 31	(305.6)	(266.5)	$ (257.8)
Net book amount at December 31	$ 67.7	$ 65.4

- Definition

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-28

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 18
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476153/220-40-55-18

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476153/220-40-55-11

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 24
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476153/220-40-55-24

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476148/220-40-50-12

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Name Accounting Standards Codification
-Section 55
-Paragraph 40
-SubTopic 30
-Topic 350
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482640/350-30-55-40

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482665/350-30-50-2

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482686/350-30-45-2

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476148/220-40-50-6

+ Details

Segment Reporting and Geographical Area Data

12 Months Ended

Dec. 31, 2025

Segment Reporting [Abstract]

Segment Reporting and Geographical Area Data

Note 3. Segment Reporting and Geographical Area Data

The Company reports its financial performance based on three reportable segments, which are Performance Chemicals, Fuel Specialties and Oilfield Services.

Our Performance Chemicals segment provides innovative technology-based solutions for our customers’ processes or products in personal care, home care, agrochemical, construction, mining and other industrial markets.

Our Fuel Specialties segment develops, manufactures, blends, markets and supplies a range of specialty chemical products used as additives in diesel, jet, marine, fuel oil and other fuels.

Our Oilfield Services segment develops and markets chemical solutions for drilling, completion, production, DRA and oil and gas applications.

In 2025 and 2024, the net sales to any single customer did not exceed 10% of the group's net sales. In 2023, the Company had a significant customer in the Oilfield Services segment which accounted for $265.2 million and 13.6% of the group's net sales.

The Chief Operating Decision Maker (“CODM”) is the President and Chief Executive Officer (the Principal Executive Officer). The CODM evaluates the performance of the Company’s segments and makes strategic decisions relating to the Company's allocation of resources, based on the segments' monthly gross profit and operating income.

The following table analyzes financial information by the Company’s reportable segments:


(in millions)	2025			2024			2023
Net Sales:
Personal Care	$	409.2		$	390.0		$	352.7
Home Care		109.0			106.6			86.8
Other		163.2			157.1			122.1
Performance Chemicals		681.4			653.7			561.6
Refinery and Performance		509.4			517.4			540.6
Other		192.1			183.7			155.3
Fuel Specialties		701.5			701.1			695.9
Oilfield Services		395.1			490.6			691.3
Total net sales	$	1,778.0		$	1,845.4		$	1,948.8
Gross profit:
Performance Chemicals		122.0			148.4			105.6
Fuel Specialties		252.2			239.9			215.1
Oilfield Services		118.2			154.6			270.4
Total gross profit	$	492.4		$	542.9		$	591.1
Operating income/(expense):
Performance Chemicals	$	61.0		$	82.9		$	54.5
Fuel Specialties		144.8			129.6			109.7
Oilfield Services		23.3			38.8			78.6
Corporate costs		(72.8	)		(70.2	)		(81.2	)
Adjustment to fair value of contingent consideration		15.9			(3.4	)		—
Restructuring charge		(0.9	)		—			—
Impairment of property, plant and equipment		(22.9	)		—			—
Impairment of intangible assets		(19.1	)		—			—
Profit on disposal of property, plant and equipment		0.2			0.2			—
Total operating income	$	129.5		$	177.9		$	161.6
Identifiable assets at year-end:
Performance Chemicals	$	602.0		$	598.3
Fuel Specialties		625.5			553.8
Oilfield Services		212.2			272.5
Corporate		392.7			310.1
Total assets	$	1,832.4		$	1,734.7

The identifiable assets analysis between the Company's reportable segments and Corporate has been updated in 2025, to align with changes made to the information provided to the CODM. The prior year comparatives have not been adjusted to conform to the current period presentation.

The difference between net sales and gross profit is defined as cost of goods sold. For further information see the relevant accounting policy within Note 2 of the Notes to the Financial Statements.

The difference between segmental gross profit and operating income/(expense) is split between selling, general and administrative expenses and research and development expenses. For further information see the relevant accounting policies within Note 2 of the Notes to the Financial Statements.

The following table analyzes cost of goods sold by the Company’s reportable segments:


(in millions)	2025		2024		2023
Performance Chemicals	$	559.4	$	505.3	$	456.0
Fuel Specialties		449.3		461.2		480.8
Oilfield Services		276.9		336.0		420.9
Total cost of goods sold	$	1,285.6	$	1,302.5	$	1,357.7

The following table analyzes selling, general and administrative expenses and research and development expenses by the Company’s reportable segments:


(in millions)	2025		2024		2023
Performance Chemicals	$	61.0	$	65.5	$	51.1
Fuel Specialties		107.4		110.3		105.4
Oilfield Services		94.9		115.8		191.8
Corporate		72.8		70.2		81.2
Total selling, general and administrative expenses and research and development expenses	$	336.1	$	361.8	$	429.5

The Company includes within the Corporate line item the following costs:

•

executive offices for the CEO, finance, human resources, legal and compliance counsel, corporate development and investor relations

•

centralized functions for product strategy, regulatory, ESG, health and safety, tax, treasury, business assurance and credit control

•

group-wide costs related to asset retirement obligations and information technology

The following tables analyze sales and other financial information by location:


(in millions)	2025			2024			2023
Net sales by source:
United States	$	951.7		$	1,039.7		$	1,227.2
United Kingdom		793.2			823.4			857.7
Rest of World		379.0			288.9			199.4
Sales between areas		(345.9	)		(306.6	)		(335.5	)
	$	1,778.0		$	1,845.4		$	1,948.8
Income before income taxes:
United States	$	25.9		$	90.2		$	95.2
United Kingdom		67.3			(24.6	)		59.1
Rest of World		44.9			(24.4	)		20.1
	$	138.1		$	41.2		$	174.4
Long-lived assets at year-end:
United States	$	132.6		$	156.2
United Kingdom		121.3			88.0
Rest of World		150.4			133.6
	$	404.3		$	377.8
Identifiable assets at year-end:
United States	$	555.9		$	593.6
United Kingdom		579.1			488.2
Rest of World		298.4			270.4
Goodwill		399.0			382.5
	$	1,832.4		$	1,734.7

Sales by geographical area are reported by source, being where the transactions originated. Intercompany sales are priced using an appropriate pricing methodology and are eliminated in the consolidated financial statements.

Long-lived assets are related to property, plant and equipment, other intangibles and operating leases.

Identifiable assets are those directly associated with the operations of the geographical area.

Goodwill has not been allocated by geographical location on the grounds that it would be impracticable to do so.

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-21

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-21

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 31
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-31

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-15

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-42

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 48
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482785/280-10-55-48

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 270
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482964/270-10-50-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (ee)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 11: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 12: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 54
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482785/280-10-55-54

Reference 13: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 47
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482785/280-10-55-47

Reference 14: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 54
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482785/280-10-55-54

Reference 15: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 47
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482785/280-10-55-47

Reference 16: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 54
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482785/280-10-55-54

Reference 17: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 47
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482785/280-10-55-47

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-22

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 34
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-34

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 26C
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-26C

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 26B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-26B

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 40
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-40

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/280/tableOfContent

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 26
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-26

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 41
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-41

+ Details

Pension and Post-Employment Benefits - Movements in PBO and Fair Value of Plan Assets (Detail) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Fair value of plan assets:
Opening balance		$ 2.4
Closing balance		0.0	$ 2.4
United Kingdom Plan [Member]
Fair value of plan assets:
Opening balance		2.5	459.2
Return of funds to cover historic expenses	$ 8.4	(0.9)	(8.4)
Scheme closure expenses		(1.6)	0.0
Benefits paid		0.0	(32.9)
Actual return on assets		0.0	1.5
Settlements		0.0	(419.2)
Exchange effect		0.0	2.3
Closing balance		0.0	2.5	$ 459.2
German Plan [Member]
Change in PBO:
Opening balance		9.0	9.1
Interest cost		0.3	0.3	0.3
Service cost/(credit)		0.0	0.0	0.1
Benefits paid		(0.5)	(0.4)
Actuarial losses/(gains)		(0.6)	0.5
Exchange effect		1.2	(0.5)
Closing balance		9.4	9.0	9.1
Pension Benefit Obligation [Member] \| United Kingdom Plan [Member]
Change in PBO:
Opening balance		0.1	424.1
Interest cost		0.0	18.6
Service cost/(credit)		1.5	(4.9)
Benefits paid		0.0	(32.9)
Plan amendments		0.0	8.4
Scheme closure expenses		(1.6)	0.0
Actuarial losses/(gains)		0.0	3.7
Settlements		0.0	(419.2)
Exchange effect		0.0	2.3
Closing balance		$ 0.0	$ 0.1	$ 424.1

Property, Plant and Equipment

12 Months Ended

Dec. 31, 2025

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

Note 6. Property, Plant and Equipment

Property, plant and equipment consists of the following:


(in millions)	2025			2024
Land	$	23.6		$	21.6
Buildings		109.7			88.7
Equipment		508.9			439.6
Work in progress		70.0			62.1
Total gross cost		712.2			612.0
Less accumulated depreciation and impairment		(426.1	)		(342.3	)
Total net book value	$	286.1		$	269.7

Of the total net book value of equipment at December 31, 2025, $0.0 million are in respect of assets held under finance leases (2024 – $0.0 million).

Depreciation charges were $32.1 million, $31.0 million and $27.9 million in 2025, 2024 and 2023, respectively.

During the quarter ended September 30, 2025, the Company impaired property, plant and equipment assets within its Oilfield Services segment. The impaired assets totaled $22.9 million and relate largely to plant and equipment, which are no longer expected to generate sufficient discounted cash flows to support the valuations due to an expected lack of near-term recovery in our oilfield production business in Mexico and our stimulation business in the U.S..

Cybersecurity Risk Management, Strategy and Governance	12 Months Ended
Cybersecurity Risk Management, Strategy and Governance	Dec. 31, 2025
Cybersecurity Risk Management, Strategy, and Governance [Line Items]
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]	Item 1C Cyber Security Risk Management & Strategy Innospec has strategically integrated cyber security risk management into its broader risk management framework to promote a company-wide culture of cyber security risk management. This integration ensures that cyber security considerations are an integral part of our decision-making processes at every level. For example, training on cyber security risks was required of all Innospec directors and employees who have access to our information technology resources. Our risk management team works closely with our Information Technology (“IT”) leadership to continuously evaluate and address cyber security risks in alignment with our business objectives and operational needs. Innospec’s IT leadership team is responsible for assessing, identifying and managing the inherent and residual risks associated with cyber security threats across our IT and operational technology landscape. IT leadership periodically reviews the Company’s external threats, portfolio, and external services, and will update its risk register accordingly. IT leadership will, when required by either executive management or the Board, engage third-party reviews of our overall cyber security compliance using The National Institute of Technology (“NIST”) framework. IT leadership will also periodically engage specialist security contractors to test the Company’s resilience to cyber security threats, conduct penetration testing and vulnerability assessments across its assets and request additional investment where necessary to further improve our cyber security. Innospec utilizes an external service to provide ongoing analysis of the security related to our critical third-party service providers for IT operations and business IT services. Innospec will use the information provided by this external service as part of its IT vendor selection criteria and for ongoing third-party risk management. Innospec’s cyber security is underpinned by a third-party specialist that monitors critical systems and end-user devices for cyber-attacks. In the first instance, cyber-attacks are brought to the attention of the IT leadership for evaluation and remediation before further escalation to the CEO and CFO is considered. Periodically, our systems are subject to targeted attacks which are intended to interrupt our operations or may lead to the loss, misuse or theft of personal information relating to our employees, suppliers and customers or lead to the loss of Company data, confidential information or our intellectual property. Governance Innospec’s Board and its committees provide oversight of the Company’s IT, including cyber security, in connection with the Company’s efforts to assess and manage the Company’s risk exposure. Oversight of risk management, including cyber security risk management is an integral part of Board and committee deliberations throughout the year. Innospec’s Board has delegated responsibility for the management of the Company’s IT to the Company's IT steering committee via the CEO and CFO. The IT steering committee is made up of executive management, business leaders from our reporting segments, the functional heads responsible for our operating systems, IT leadership and is chaired by our Global IT Director. The Company considers that the IT steering committee members have the appropriate qualifications and experience required to enable them to fulfill their responsibilities. The IT steering committee may, as per its agreed terms of reference, escalate any matter it wishes to the Board via either the CEO or CFO. IT leadership is made up of senior managers with the appropriate qualifications and business experience required for their roles overseeing Innospec’s IT operations. In addition, the IT leadership team includes specialists with many years cyber security experience at both Innospec and previously with other organizations, combined with multiple cyber security qualifications. Innospec's IT leadership formally reports through the CEO and CFO to the Board. Innospec’s CEO and CFO are involved with and approve the Company’s strategy for managing the prevention, detection, mitigation and remediation of cyber security incidents as part of its “IT Security Management System” which includes defined escalation and internal communications processes and responsibilities. IT leadership will, as required, present to the IT steering committee, information regarding any IT risks identified and the mitigation plans to reduce the Company’s residual risks. The IT steering committee will be regularly updated as to the occurrence, mitigation and resolution of cyber security incidents. Any cyber security incident that is considered significant in nature will be shared by IT leadership with the IT steering committee in accordance with the agreed communication and escalation processes. The IT steering committee will assess the incident and make a recommendation to the CEO and CFO as to whether the incident is reportable to the SEC and/or other regulators or stakeholders. In the last three fiscal years, management has determined there were no cyber security threats that have materially affected Innospec and that the expenses incurred relating to cyber incidents have been immaterial. The Company is not aware of any threats that are reasonably likely to materially affect its business strategy, results of operations or financial condition for the foreseeable future. IT leadership provides a written report to the Board each quarter and the Global IT Director presents in person at least annually. Those reports and presentations include information on Innospec’s cyber security and the related key performance indicators. IT leadership also provides external threat analysis to the Board when new relevant threats are identified as being exploitable and their potential impact on Innospec.
Cybersecurity Risk Management Processes Integrated [Flag]	true
Cybersecurity Risk Management Processes Integrated [Text Block]	Innospec has strategically integrated cyber security risk management into its broader risk management framework to promote a company-wide culture of cyber security risk management. This integration ensures that cyber security considerations are an integral part of our decision-making processes at every level. For example, training on cyber security risks was required of all Innospec directors and employees who have access to our information technology resources. Our risk management team works closely with our Information Technology (“IT”) leadership to continuously evaluate and address cyber security risks in alignment with our business objectives and operational needs.
Cybersecurity Risk Management Third Party Engaged [Flag]	true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag]	true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag]	false
Cybersecurity Risk Board of Directors Oversight [Text Block]	Innospec’s Board and its committees provide oversight of the Company’s IT, including cyber security, in connection with the Company’s efforts to assess and manage the Company’s risk exposure. Oversight of risk management, including cyber security risk management is an integral part of Board and committee deliberations throughout the year. Innospec’s Board has delegated responsibility for the management of the Company’s IT to the Company's IT steering committee via the CEO and CFO. The IT steering committee is made up of executive management, business leaders from our reporting segments, the functional heads responsible for our operating systems, IT leadership and is chaired by our Global IT Director. The Company considers that the IT steering committee members have the appropriate qualifications and experience required to enable them to fulfill their responsibilities. The IT steering committee may, as per its agreed terms of reference, escalate any matter it wishes to the Board via either the CEO or CFO. IT leadership is made up of senior managers with the appropriate qualifications and business experience required for their roles overseeing Innospec’s IT operations. In addition, the IT leadership team includes specialists with many years cyber security experience at both Innospec and previously with other organizations, combined with multiple cyber security qualifications. Innospec's IT leadership formally reports through the CEO and CFO to the Board. Innospec’s CEO and CFO are involved with and approve the Company’s strategy for managing the prevention, detection, mitigation and remediation of cyber security incidents as part of its “IT Security Management System” which includes defined escalation and internal communications processes and responsibilities. IT leadership will, as required, present to the IT steering committee, information regarding any IT risks identified and the mitigation plans to reduce the Company’s residual risks. The IT steering committee will be regularly updated as to the occurrence, mitigation and resolution of cyber security incidents. Any cyber security incident that is considered significant in nature will be shared by IT leadership with the IT steering committee in accordance with the agreed communication and escalation processes. The IT steering committee will assess the incident and make a recommendation to the CEO and CFO as to whether the incident is reportable to the SEC and/or other regulators or stakeholders. In the last three fiscal years, management has determined there were no cyber security threats that have materially affected Innospec and that the expenses incurred relating to cyber incidents have been immaterial. The Company is not aware of any threats that are reasonably likely to materially affect its business strategy, results of operations or financial condition for the foreseeable future. IT leadership provides a written report to the Board each quarter and the Global IT Director presents in person at least annually. Those reports and presentations include information on Innospec’s cyber security and the related key performance indicators. IT leadership also provides external threat analysis to the Board when new relevant threats are identified as being exploitable and their potential impact on Innospec.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]	The IT steering committee is made up of executive management, business leaders from our reporting segments, the functional heads responsible for our operating systems, IT leadership and is chaired by our Global IT Director. The Company considers that the IT steering committee members have the appropriate qualifications and experience required to enable them to fulfill their responsibilities. The IT steering committee may, as per its agreed terms of reference, escalate any matter it wishes to the Board via either the CEO or CFO.
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block]	IT leadership provides a written report to the Board each quarter and the Global IT Director presents in person at least annually. Those reports and presentations include information on Innospec’s cyber security and the related key performance indicators. IT leadership also provides external threat analysis to the Board when new relevant threats are identified as being exploitable and their potential impact on Innospec.
Cybersecurity Risk Role of Management [Text Block]	Innospec’s CEO and CFO are involved with and approve the Company’s strategy for managing the prevention, detection, mitigation and remediation of cyber security incidents as part of its “IT Security Management System” which includes defined escalation and internal communications processes and responsibilities.
Cybersecurity Risk Management Positions or Committees Responsible [Flag]	true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]	Innospec’s Board has delegated responsibility for the management of the Company’s IT to the Company's IT steering committee via the CEO and CFO
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]	IT leadership is made up of senior managers with the appropriate qualifications and business experience required for their roles overseeing Innospec’s IT operations. In addition, the IT leadership team includes specialists with many years cyber security experience at both Innospec and previously with other organizations, combined with multiple cyber security qualifications.
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]	The IT steering committee will be regularly updated as to the occurrence, mitigation and resolution of cyber security incidents. Any cyber security incident that is considered significant in nature will be shared by IT leadership with the IT steering committee in accordance with the agreed communication and escalation processes. The IT steering committee will assess the incident and make a recommendation to the CEO and CFO as to whether the incident is reportable to the SEC and/or other regulators or stakeholders.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag]	true

Plant Closure Provisions

12 Months Ended

Dec. 31, 2025

Restructuring and Related Activities [Abstract]

Plant Closure Provisions

Note 13. Plant Closure Provisions

The Company has continuing plans to remediate manufacturing facilities at sites around the world as and when those operations are expected to cease or we are required to decommission the sites according to local laws and regulations. The liability for estimated plant closure costs includes costs for asset retirement obligations and environmental remediation liabilities.

The principal site giving rise to asset retirement obligations is the site at Ellesmere Port in the United Kingdom. There are also asset retirement obligations on a much smaller scale in respect of other sites. Environmental remediation liabilities are insignificant.

Movements in the provisions are summarized as follows:


(in millions)	2025			2024			2023
Total at January 1	$	60.3		$	61.6		$	57.2
Charge for the period		5.6			4.7			8.9
Utilized in the period		(5.8	)		(3.8	)		(4.9	)
Exchange effect		5.0			(2.2	)		0.4
Total at December 31		65.1			60.3			61.6
Due within one year		(4.9	)		(5.0	)		(4.6	)
Due after one year	$	60.2		$	55.3		$	57.0

Amounts due within one year refer to provisions where expenditure is expected to arise within one year of the balance sheet date.

The charge for the period in 2025 represents the accretion expense recognized of $3.6 million and a further $2.0 million primarily in respect of changes in the expected cost, scope and timing of future obligations. The charges for plant closure provisions are recognized in cost of goods sold for our reporting segments and within selling, general and administrative expenses for Corporate costs.

We recognize environmental remediation liabilities when they are probable and the costs can be reasonably estimated, and asset retirement obligations when there is an obligation based on a legal requirement, including those arising from a Company promise, and the costs can be reasonably estimated. The Company has to make significant judgments when anticipating the program of work required and the associated future expected costs, and comply with environmental legislation in the countries in which it operates or has operated in.

Expenditure utilizing plant closure provisions was $5.8 million, $3.8 million and $4.9 million in 2025, 2024 and 2023, respectively.

Long-Term Debt - Summary of Debt Refinancing Costs (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Gross cost at January 1	$ 1.7	$ 1.4
Capitalized in the year	0.0	0.3
Gross cost	1.7	1.7	$ 1.4
Accumulated amortization,Beginning Balance	(0.6)	(0.2)
Amortization in the year	(0.4)	(0.4)	(0.4)
Accumulated amortization,Ending balance	(1.0)	(0.6)	$ (0.2)
Deferred finance costs, net	$ 0.7	$ 1.1

Segment Reporting and Geographical Area Data - Segment Reporting on Basis of Geographical Location (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Jul. 31, 2025
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 1,778.0	$ 1,845.4	$ 1,948.8
Income before income taxes	138.1	41.2	174.4
Long-lived assets at year end	404.3	377.8
Goodwill	399.0	382.5	399.3	$ 2.0
Identifiable assets at year end	1,832.4	1,734.7
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	951.7	1,039.7	1,227.2
Income before income taxes	25.9	90.2	95.2
Long-lived assets at year end	132.6	156.2
Identifiable assets at year end	555.9	593.6
United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	793.2	823.4	857.7
Income before income taxes	67.3	(24.6)	59.1
Long-lived assets at year end	121.3	88.0
Identifiable assets at year end	579.1	488.2
Rest of World [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	379.0	288.9	199.4
Income before income taxes	44.9	(24.4)	20.1
Long-lived assets at year end	150.4	133.6
Identifiable assets at year end	298.4	270.4
Sales Between Areas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ (345.9)	$ (306.6)	$ (335.5)

Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2025

Goodwill and Intangible Assets Disclosure [Abstract]

Summary of Other Intangible Assets

The following table analyzes other intangible assets movement for 2025 and 2024.


(in millions)	2025			2024
Gross cost at January 1	$	331.9		$	315.1
Additions		23.6			24.3
Exchange effect		17.8			(7.5	)
Gross cost at December 31		373.3			331.9
Accumulated amortization at January 1		(266.5	)		(257.8	)
Amortization expense		(11.6	)		(12.6	)
Impairment		(19.0	)		—
Exchange effect		(8.5	)		3.9
Accumulated amortization at December 31		(305.6	)		(266.5	)
Net book amount at December 31	$	67.7		$	65.4

Schedule of Amortization Expense

Other intangible assets at December 31, 2025 were:


(in millions)	Gross carrying amount		Accumulated amortization
Product rights	$	34.0	$	(34.0	)
Brand names		8.9		(8.9	)
Technology		55.1		(55.1	)
Customer relationships		137.3		(129.2	)
Internally developed software		113.4		(53.8	)
Other		24.6		(24.6	)
	$	373.3	$	(305.6	)

Other intangible assets at December 31, 2024 were:


(in millions)	Gross carrying amount		Accumulated amortization
Product rights	$	34.0	$	(34.0	)
Brand names		8.9		(8.9	)
Technology		55.1		(44.6	)
Customer relationships		130.6		(111.9	)
Internally developed software		78.7		(42.5	)
Other		24.6		(24.6	)
	$	331.9	$	(266.5	)

Future amortization expense is estimated to be as follows for the next five years:


(in millions)
2026	$	9.9
2027	$	6.5
2028	$	6.2
2029	$	6.2
2030	$	6.2

Leases - Supplemental Balance Sheet Information Related to Leases (Detail) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Operating Leases:
Operating leases right-of-use assets	$ 52.7	$ 44.8
Current portion of operating lease liabilities	15.9	13.9
Operating lease liabilities, net of current portion	36.8	31.0
Total operating lease liabilities	$ 52.7	$ 44.9
Weighted average remaining lease term:
Operating leases	6 years 3 months 18 days	5 years 7 months 6 days
Weighted average discount rate:
Operating leases	4.10%	3.80%

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Statement of Financial Position [Abstract]
Allowances for doubtful accounts	$ 11.8	$ 11.9
Inventory allowances	$ 40.4	$ 34.6
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	40,000,000	40,000,000
Common stock, shares issued	29,554,500	29,554,500
Treasury stock, shares	4,776,918	4,594,943

Stockholders' Equity - Additional Information (Detail) - shares	Dec. 31, 2025	Dec. 31, 2024
Equity [Abstract]
Common stock, shares authorized	40,000,000	40,000,000

Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2025

Accounting Policies [Abstract]

Basis of preparation

Basis of preparation: The consolidated financial statements have been prepared in accordance with generally accepted accounting principles (“GAAP”) in the United States of America on a going concern basis and include all subsidiaries of the Company where the Company has a controlling financial interest. All intercompany accounts and balances have been eliminated upon consolidation. In accordance with GAAP in the United States of America, the results of operations of an acquired or disposed business are included or excluded from the consolidated financial statements from the date of acquisition or disposal.

During the year, the Company has reclassified prior period amounts to conform to the 2025 presentation relating to research and development expenditure. The reclassification had no impact on previously reported total net revenue, operating income or net income. For the year ended December 31, 2025, this has resulted in $6.9 million (2024 $8.7 million - 2023 $7.3 million) of costs that were previously disclosed within selling, general and administrative expenses, being moved to research and development expenses.

Use of estimates

Use of estimates: The preparation of the consolidated financial statements, in accordance with GAAP in the United States of America, requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates.

Revenue recognition

Revenue recognition: Our revenues are primarily derived from the manufacture and sale of specialty chemicals. We recognize revenue when control of the product is transferred to our customer and for an amount that reflects the consideration we expect to collect from the customer. Control is generally transferred to the customer when title transfers (which may include physical possession by the customer), we have a right to payment from the customer, the customer has accepted the product, and the customer has assumed the risks and rewards of ownership. We have supplier managed inventory arrangements with some of our customers to facilitate on-demand product availability. In some cases, the inventory resides at a customer site, although title has not transferred, we are not entitled to payment, and we have not invoiced for the product. We have evaluated the contract terms under these arrangements and have determined that control transfers when the customer uses the product, at which time revenue is recognized. Our contracts generally include one performance obligation, which is providing specialty chemicals. The performance obligation is satisfied at a point in time when products are shipped, delivered, or consumed by the customer, depending on the underlying contracts.

While some of our customers have payment terms beyond 30 days, we do not provide extended payment terms of a year or more, nor do our contracts include a financing component. Some of our contracts include variable consideration in the form of rebates. We record rebates at the point of sale as a reduction in sales

when we can reasonably estimate the amount of the rebate. The estimates are based on our best judgment at the time of sale, which includes anticipated as well as historical performance.

Taxes assessed by a governmental authority which are concurrent with sales to our customers, including sales, use, value-added, and revenue-related excise taxes, are collected by us from the customer and are not included in net sales, but are reflected in accrued liabilities until remitted to the appropriate governmental authority. When we are responsible for shipping and handling costs after title has transferred, we account for those as fulfillment costs and include them in cost of goods sold.

Components of net sales

Components of net sales: All amounts billed to customers relating to shipping and handling are classified as net sales. Shipping and handling costs incurred by the Company are classified as cost of goods sold.

Components of cost of goods sold

Components of cost of goods sold: Cost of goods sold is comprised of raw material costs including inbound freight, duty and non-recoverable taxes, inbound handling costs associated with the receipt of raw materials, packaging materials, manufacturing costs including labor costs, maintenance and utility costs, plant and engineering overheads, amortization expense for certain other intangible assets, warehousing and outbound shipping costs and handling costs. Inventory losses and provisions and the costs of customer claims are also recognized in the cost of goods line item.

Components of selling, general and administrative expenses

Components of selling, general and administrative expenses: Selling expenses comprise the costs of the direct sales force, and the sales management and customer service departments required to support them. It also comprises commission charges, the costs of sales conferences and trade shows, the cost of advertising and promotions, amortization expense for certain other intangible assets, and the cost of bad and doubtful debts. General and administrative expenses comprise the cost of functions including accounting, human resources, information technology and the cost of group functions including corporate management, finance, tax, treasury, investor relations and legal departments. Provision of management’s best estimate of legal and settlement costs for litigation in which the Company is involved is accounted for in the administrative expense line item.

Research and development expenses

Research and development expenses: Research, development and testing costs are expensed to the income statement as incurred.

Earnings per share

Earnings per share: Basic earnings per share is based on the weighted average number of common shares outstanding during the period. Diluted earnings per share includes the effect of options that are dilutive and outstanding during the period.

Foreign currencies

Foreign currencies: The Company’s policy is that foreign exchange differences arising on the translation of the balance sheets of entities that have functional currencies other than the U.S. dollar are taken to a separate equity reserve, the cumulative translation adjustment. In entities where the U.S. dollar is the functional currency no gains or losses on translation occur, and gains or losses on monetary assets relating to currencies other than the U.S. dollar are taken to the income statement in other income/(expense), net. Gains and losses on intercompany foreign currency loans which are long-term in nature, which the Company does not intend to settle in the foreseeable future, are also recorded in accumulated other comprehensive loss. Other foreign exchange gains or losses are also included in other income, net in the income statement.

Share-based compensation plans

Share-based compensation plans: The Company accounts for employee stock options and stock equivalent units under the fair value method. Stock options are fair valued at the grant date and the fair value is recognized straight-line over the vesting period of the option. Stock equivalent units are fair valued at each balance sheet date and the fair value is spread over the remaining vesting period of the unit. The Company operates an employee stock purchase plan, or ESPP, which enables employees to purchase Innospec's stock at a discount.

Business combinations

Business combinations: The acquisition method of accounting requires that we recognize the assets acquired and liabilities assumed at their acquisition date fair values. Goodwill is measured as the excess of consideration transferred over the acquisition date net fair values of the assets acquired and the liabilities assumed.

The determination of the fair values of certain assets and liabilities are usually based on significant estimates provided by management, such as forecast revenue or profit. In determining the fair value of intangible assets, an income approach is generally used and may incorporate the use of a discounted cash flow method. In applying the discounted cash flow method, the estimated future cash flows and residual values for each intangible asset are discounted to a present value using a discount rate appropriate to the business being acquired. These cash flow projections are based on management’s estimates of economic and market conditions including revenue growth rates, operating margins, capital expenditures and working capital requirements.

Cash equivalents

Cash equivalents: Investment securities with maturities of three months or less when purchased are considered to be cash equivalents.

Trade and other accounts receivable

Trade and other accounts receivable: The Company records trade and other accounts receivable at net realizable value and maintains allowances for customers not making required payments. The Company determines the adequacy of allowances by periodically evaluating each customer receivable considering our customer’s financial condition, credit history and current economic conditions.

The Company is exposed to credit losses primarily through sales of products. The Company’s expected loss allowance methodology for trade and other accounts receivable is developed using historical collection experience, current and future economic and market conditions and a review of the current status of customers’ receivables. Due to the short-term nature of such receivables, the estimate of accounts receivable amounts that may not be collected is based on aging of the accounts receivable balances and the financial condition of customers. Additionally, a further allowance is included to account for the Company’s historical track record of credit losses, for balances which are not aged sufficiently to be considered under the aging based approach.

Inventories

Inventories: Inventories are stated at the lower of cost (FIFO method) or market value. Cost includes materials, labor and an appropriate proportion of plant overheads. The Company accrues volume discounts where it is probable that the required volume will be attained and the amount can be reasonably estimated. The volume discounts are recorded as a reduction in the cost of materials based on projected purchases over the period of the agreement. Inventories are adjusted for estimated obsolescence and written down to market value based on estimates of future demand and market conditions.

Acquisition-related contingent consideration: Contingent consideration payable in cash is discounted to its fair value at each balance sheet date using the Company’s credit-adjusted risk-free rate. Where contingent consideration is dependent upon pre-determined financial targets, an estimate of the fair value of the likely consideration payable is made at each balance sheet date.

Property, plant and equipment

Property, plant and equipment: Property, plant and equipment are stated at cost less accumulated depreciation. Depreciation is provided over the estimated useful lives of the assets using the straight-line method and is allocated between cost of goods sold and operating expenses. The cost of additions and improvements are capitalized. Maintenance and repairs are charged to expenses as incurred. When assets are sold or retired the associated cost and accumulated depreciation are removed from the consolidated financial statements and any related gain or loss is included in earnings. The estimated useful lives of the major classes of depreciable assets are as follows:


Buildings		7 to 25 years
Equipment		3 to 10 years

Goodwill and other intangible assets

Goodwill: Goodwill is deemed to have an indefinite life and is subject to at least annual impairment assessments at the reporting unit level. The Company considers that its reporting units are consistent with its reportable segments. The components in each segment (including products, markets and competitors) have similar economic characteristics and the segments, therefore, reflect the lowest level at which operations and cash flows can be sufficiently distinguished, operationally and for financial reporting purposes, from the rest of the Company.

Initially we perform a qualitative assessment to determine whether it is more likely than not (that is, a likelihood of more than 50%) that the fair value of a reportable segment is less than the carrying amount prior to performing a quantitative goodwill impairment test. The annual measurement date for impairment assessment of the goodwill relating to the Performance Chemicals, Fuel Specialties and Oilfield Services segments is December 31 each year. Factors utilized in the qualitative assessment process include macroeconomic conditions, industry and market considerations, cost factors, overall financial performance and Company specific events.

If a quantitative test is required, we assess the fair value based on projected post-tax cash flows discounted at the Company’s weighted average cost of capital. These fair value techniques require management judgment and estimates including revenue growth rates, projected operating margins, changes in working capital and discount rates. We would develop these assumptions by considering recent financial performance and industry growth estimates.

Other intangible assets: Other intangible assets are deemed to have finite lives and are amortized using the straight-line method over their estimated useful lives. The Company capitalizes software development costs as intangible assets, including licenses, subsequent to the establishment of technological feasibility. These assets are tested for potential impairment when events occur or circumstances change, which suggest an impairment may have occurred.

In order to facilitate testing for potential impairment the Company groups together assets at the lowest possible level for which cash flow information is available. Undiscounted future cash flows expected to result from the asset groups are compared with the carrying value of the assets and, if such cash flows are lower, an impairment loss may be recognized. The amount of the impairment loss is the difference between the fair value and the carrying value of the assets. Fair values are determined using post-tax cash flows discounted at the Company’s weighted average cost of capital. If events occur or circumstances change it may cause a reduction in the periods over which the assets are amortized or result in a non-cash impairment of their carrying value. A reduction in the amortization periods would have no impact on cash flows.

The estimated useful lives of the major classes of assets are as follows:


Technology		10 to 17 years
Customer lists		7 to 15 years
Brand names		5 to 10 years
Product rights		9 to 10 years
Internally developed software		3 to 12 years
Marketing related		11 years

Leases

Leases: We determine if an arrangement is a lease at inception. The present value of the future lease payments for operating leases is included in operating lease right-of-use (“ROU”) assets, and operating lease liabilities (current and non-current) on our consolidated balance sheet at the reporting date. The carrying value of assets under finance leases is included in property, plant and equipment and finance lease liabilities (current and non-current) on our consolidated balance sheet at the reporting date.

Operating lease ROU assets and operating lease liabilities are recognized based on the present value of future lease payments over the remaining lease term. Very few of our leases have renewal options or early termination break clauses, but where they do, we have assessed the term of the lease based on any options being exercised only if they are reasonably certain. As most of our leases do not provide an implicit interest rate, we use our incremental borrowing rate based on the information available at point of recognition in determining the present value of future payments.

The operating lease ROU asset excludes lease incentives and initial direct costs incurred. Lease expense for lease payments is recognized on a straight-line basis over the lease term unless payments are variable per the agreement. We do not separate related non-lease components from lease components. Where we have lease payments linked to an index or inflationary rate, this rate has been used to value the asset and liability at the inception of the lease. If the payments are not linked to a specific index or inflationary rate, but can vary during the term of the agreement, they have been included at their actual value for each future period. In some circumstances the future expected payments may be dependent on other factors, for example production volumes, in which case we have used the minimum future expected payments to value the asset.

We do not recognize a ROU asset or operating lease liability for short-term leases (with a length of one year or less), and any associated cost is recognized, as incurred, through the income statement.

Deferred finance costs

Deferred finance costs: The costs relating to debt financing are capitalized and amortized using the effective interest method over the expected life of the debt financing facility. The amortization charge is included in interest expense in the income statement.

Impairment of long-lived assets

Impairment of long-lived assets: The Company reviews the carrying value of its long-lived assets, including buildings and equipment, whenever changes in circumstances suggest that the carrying values may be impaired. In order to facilitate this test, the Company groups together assets at the lowest possible level for which cash flow information is available. Undiscounted future cash flows expected to result from the asset groups are compared with the carrying value of the asset groups and if they are lower an impairment loss may be recognized. The amount of the impairment loss is the difference between the fair value and the carrying value of the asset groups. Fair values are determined using post-tax cash flows discounted at the Company’s weighted average cost of capital.

Derivative instruments

Derivative instruments: From time to time, the Company uses various derivative instruments including forward currency contracts, options, interest rate swaps and commodity swaps to manage certain exposures. These instruments are entered into under the Company’s corporate risk management policy to minimize exposure and are not for speculative trading purposes. The Company recognizes all derivatives as either current or non-current assets or liabilities in the consolidated balance sheet and measures those instruments at fair value. Changes in the fair value of derivatives that are not designated as hedges, or do not meet the requirements for hedge accounting, are recognized in earnings. Derivatives which are designated as hedges are tested for effectiveness on a quarterly basis and marked to market. The ineffective portion of the derivative’s change in value is recognized in earnings. The effective portion is recognized in other comprehensive income until the hedged item is recognized in earnings.

Plant closure provisions

Plant closure provisions: This includes both environmental compliance and remediation costs. Environmental compliance costs include ongoing maintenance, monitoring and similar costs and extend to environmental liabilities that result from other-than-normal operation of long-lived assets, for example pollution. Remediation costs relate to asset retirement obligations at our current and former manufacturing sites following retirement of the long-lived assets, linked to their normal operation. We recognize environmental remediation liabilities when they are probable and the costs can be reasonably estimated, and asset retirement obligations when there is an obligation based on a legal requirement, including those arising from a Company promise, and the costs can be reasonably estimated. The vast majority of our plant closure provision relates to our Ellesmere Port site in the United Kingdom.

The Company must comply with environmental legislation in the countries in which it operates or has operated in and annually reassesses the program of work required. This includes applying significant judgments and estimating the credit-adjusted risk-free rate and the timing and cost of performing the remediation work. Management receives input from specialists to develop these estimates and assumptions utilizing the latest information available together with experience of recent costs. While we believe our assumptions for the liabilities are reasonable, they are subjective estimates and it is possible that variations in any of the assumptions will result in materially different calculations to the liabilities we have reported. Costs of future obligations are discounted to their present values using the Company’s credit-adjusted risk-free rate.

Pension plans and other post-employment benefits

Pension plans and other post-employment benefits: The Company recognizes the funded status of defined benefit post-retirement plans on the consolidated balance sheets and changes in the funded status in comprehensive income. The measurement date of the plan’s funded status is the same as the Company’s fiscal year-end. The service costs are recognized as employees render the services necessary to earn the post-employment benefits. Prior service costs and credits and actuarial gains and losses are amortized over the average remaining life expectancy of the inactive participants using the corridor method. The insurance contracts are adjusted each reporting period to reflect the estimated fair value of the premium that would be paid for such contracts at that time.

Movements in the Projected Benefit Obligation (“PBO”) are dependent on our assumptions in respect of the discount rate, annual member mortality rates, future return on assets and future inflation.

Income taxes

Income taxes: The Company provides for income taxes by recognizing deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial statement carrying amounts and the relevant tax bases of the assets and liabilities. The Company then evaluates the need for a valuation allowance to reduce deferred tax assets to the amount more likely than not to be realized. The effect on deferred taxes of a change in tax rates is recognized in the period that includes the enactment date. The Company recognizes the tax benefit from a tax position only if it is more likely than

not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the financial statements from such positions are then measured based on the largest benefit that has a greater than 50% likelihood of being realized upon settlement. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs. The Company recognizes accrued interest and penalties associated with unrecognized tax benefits as part of income taxes in our consolidated statements of income if required.

Reclassifications out of Accumulated Other Comprehensive Loss - Summary of Reclassifications out of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service cost	$ 0.0	$ 8.4	$ 0.5
Amortization of actuarial net losses/(gains)	0.0	(0.2)	$ (2.1)
Total reclassifications	(0.0)	(98.5)
Defined Benefit Pension Plan Items [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications	0.0	(98.5)
Reclassification Out of Accumulated Other Comprehensive Income/(Loss) [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	0.0	146.3
Income tax expense	0.0	(47.8)
Total reclassifications	0.0	(98.5)
Reclassification Out of Accumulated Other Comprehensive Income/(Loss) [Member] \| Defined Benefit Pension Plan Items [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service cost	0.0	8.4
Amortization of actuarial net losses/(gains)	$ 0.0	(0.2)
Pension scheme settlement		$ 138.1

- Definition

Amount after tax of reclassification adjustments of other comprehensive income (loss).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-14A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480870/815-30-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-5

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-17

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 20
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-20

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(19))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-4

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-SubTopic 10
-Topic 220
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482739/220-10-55-15

+ Details

Pension and Post-Employment Benefits (Tables)

12 Months Ended

Dec. 31, 2025

Plan Net Pension Credit


(in millions)	2025		2024			2023
Service cost/(credit)	$	1.5	$	(4.9	)	$	3.4
Interest cost on PBO		—		18.6			19.6
Expected return on plan assets		—		(25.9	)		(25.2	)
Amortization of prior service cost		—		16.8			0.5
Amortization of actuarial net losses		—		—			(1.6	)
Recycling of residual reserves		—		138.8			—
Net periodic cost/(benefit)	$	1.5	$	143.4		$	(3.3	)

The income statement captions are shown here:


Selling, general and administrative	2025		2024			2023
Service cost/(credit)	$	1.5	$	(4.9	)	$	3.4

Other expense/(income), net	2025		2024			2023
Interest cost on PBO	$	—		18.6			19.6
Expected return on plan assets		—		(25.9	)		(25.2	)
Amortization of prior service cost		—		—			0.5
Amortization of actuarial net losses		—		—			(1.6	)
	$	—	$	(7.3	)	$	(6.7	)

Pension scheme settlement charge	2025		2024			2023
Amortization of prior service cost	$	—		16.8			—
Recycling of residual reserves		—		138.8			—
		—		155.6			—
Tax relating to the amortization of prior service cost		—		(4.2	)		—
Tax relating to the recycling of residual reserves		—		(34.7	)		—
	$	—	$	116.7		$	—

The other financial statement captions relating to the buy-out settlement are shown here:


Recognized in Other Comprehensive Income	2025		2024			2023
Recycling of residual reserves	$	—		138.8			—
Release of historic cumulative translation adjustments		—		(0.7	)		—
		—		138.1			—
Tax relating to the recycling of residual reserves		—		(34.7	)		—
Tax relating to historic cumulative translation adjustments		—		(11.0	)		—
	$	—	$	92.4		$	—

Recognized in Reclassifications out of Accumulated Other Comprehensive Loss	2025		2024			2023
Recycling of residual reserves	$	—		138.8			—
Release of historic cumulative translation adjustments		—		(0.7	)		—
		—		138.1			—
Tax relating to the recycling of residual reserves		—		(34.7	)		—
Tax relating to historic cumulative translation adjustments		—		(11.0	)		—
	$	—	$	92.4		$	—


Plan assumptions at December 31, (%):	2025	2024		2023
Discount rate	n/a		5.18		4.59
Inflation rate	n/a		2.85		2.70
Rate of return on plan assets – overall on bid-value	n/a		4.20		4.25


Plan asset allocation by category (%):	2025	2024		2023
Debt securities and insurance contracts	n/a		—		96
Cash	n/a		100		4
	n/a		100		100

Movements in PBO and Fair Value of Plan Assets

Movements in PBO and fair value of UK Plan assets are as follows:


(in millions)	2025			2024
Change in PBO:
Opening balance	$	0.1		$	424.1
Interest cost		—			18.6
Service cost/(credit)		1.5			(4.9	)
Benefits paid		—			(32.9	)
Plan amendments		—			8.4
Scheme closure expenses		(1.6	)		—
Actuarial losses/(gains)		—			3.7
Settlements		—			(419.2	)
Exchange effect		—			2.3
Closing balance	$	—		$	0.1
Fair value of plan assets:
Opening balance	$	2.5		$	459.2
Return of funds to cover historic expenses		(0.9	)		(8.4	)
Scheme closure expenses		(1.6	)		—
Benefits paid		—			(32.9	)
Actual return on assets		—			1.5
Settlements		—			(419.2	)
Exchange effect		—			2.3
Closing balance	$	—		$	2.5
Net pension asset	$	—		$	2.4

Fair Value of Pension Assets

The fair values of pension assets by level of input were as follows:


(in millions)	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
At December 31, 2024
Cash		2.5						2.5
Total plan assets	$	2.5	$	—	$	—	$	2.5

Reconciliation of Fair Value of Plan Assets Measured Using Significant Unobservable Inputs

The reconciliation of the fair value of the UK Plan assets measured using significant unobservable inputs was as follows:


(in millions)	Other Assets
Balance at December 31, 2023	$	438.7
Realized/unrealized gains/(losses):
Relating to assets still held at the reporting date		(2.2	)
Purchases, issuances and settlements		(438.8	)
Exchange effect		2.3
Balance at December 31, 2024	$	—

German Plan [Member]

Plan Net Pension Credit

The service cost shown in the table below has been recognized in selling, general and administrative expenses within Corporate costs and the other items recognized within other income, net.


(in millions)	2025		2024			2023
Service cost	$	—	$	—		$	0.1
Interest cost on PBO		0.3		0.3			0.3
Amortization of actuarial net loss/(gain)		—		(0.2	)		(0.5	)
Net periodic cost/(benefit)	$	0.3	$	0.1		$	(0.1	)

Plan assumptions at December 31, (%):


Discount rate	3.80	3.20	3.70
Inflation rate	2.25	2.25	2.25
Rate of increase in compensation levels	2.75	2.75	2.75

Movements in PBO and Fair Value of Plan Assets

Movements in PBO of the German plan are as follows:


(in millions)	2025			2024
Change in PBO:
Opening balance	$	9.0		$	9.1
Service cost		—			—
Interest cost		0.3			0.3
Benefits paid		(0.5	)		(0.4	)
Actuarial losses/(gains)		(0.6	)		0.5
Exchange effect		1.2			(0.5	)
Closing balance	$	9.4		$	9.0

- Definition

Tabular disclosure of the fair value measurement of assets using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes during the period attributable to the following: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets) and gains or losses recognized in other comprehensive income (loss), and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issues, and settlements (each type disclosed separately); and (3) transfers in and transfers out of Level 3 (for example, transfers due to changes in the observability of significant inputs), by class of asset.

+ References + Details

Derivative Instruments and Risk Management - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Derivative [Line Items]
Interest rate swaps notional value	$ 0.0	$ 0.0
Foreign currency forward exchange contracts notional value	$ 238.9	212.8
Maximum [Member]
Derivative [Line Items]
Maturity period of foreign currency forward exchange contracts	12 months
Emission Trading Scheme Credits [Member] \| UNITED KINGDOM
Derivative [Line Items]
Commodity contract asset non current	$ 3.2	3.9
Not Designated as Hedging Instrument [Member] \| Foreign Currency Forward Exchange Contracts [Member] \| Other net income/(expense) [Member]
Derivative [Line Items]
Amount of gain/(loss) recognized in income	$ 3.1	$ 5.3

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Tax Contingency [Line Items]
Deferred tax assets valuation allowance	$ 2,800,000	$ 2,400,000
Deferred tax asset recognition	9,500,000
Credit to net income	9,500,000
Adjustment to fair value of contingent consideration	(15,900,000)	3,400,000	$ 0
Unrecognized tax benefit	0	$ 0	$ 14,800,000	$ 13,400,000
QGP
Income Tax Contingency [Line Items]
Adjustment to fair value of contingent consideration	15,900,000
Foreign [Member] \| Indefinitely [Member]
Income Tax Contingency [Line Items]
Operating loss carry forwards	$ 6,800,000

Accounting Policies - Estimated Useful Lives of Major Classes of Depreciable Assets (Detail)	Dec. 31, 2025
Buildings [Member] \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of assets	7 years
Buildings [Member] \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of assets	25 years
Equipment [Member] \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of assets	3 years
Equipment [Member] \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of assets	10 years

Pension and Post-Employment Benefits - Defined Benefit Pension Plan (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Plan net pension (credit)/charge:
Pension scheme settlement		$ 92.4
Other Nonoperating Income (Expense), Total	$ (0.6)	9.6	$ 10.5
One Time pension scheme settlement charge	0.0	$ 155.6	$ 0.0
United Kingdom Plan [Member]
Plan assumptions at December 31, (%):
Discount rate		5.18%	4.59%
Inflation rate		2.85%	2.70%
Rate of return on plan assets - overall on bid-value		4.20%	4.25%
Plan asset allocation by category (%):
Total plan asset allocation by category		100.00%	100.00%
United Kingdom Plan [Member] \| Cash [Member]
Plan asset allocation by category (%):
Total plan asset allocation by category		100.00%	4.00%
United Kingdom Plan [Member] \| Defined Benefit Plan Debt Securities And Insurance Contracts [Member]
Plan asset allocation by category (%):
Total plan asset allocation by category		0.00%	96.00%
United Kingdom [Member] \| United Kingdom Plan [Member]
Plan net pension (credit)/charge:
Service cost/(credit)	1.5	$ (4.9)	$ 3.4
Interest cost on PBO	0.0	18.6	19.6
Expected return on plan assets	0.0	(25.9)	(25.2)
Amortization of prior service cost	0.0	16.8	0.5
Amortization of actuarial net losses	0.0	0.0	(1.6)
Recycling of residual reserves	0.0	138.8	0.0
Net periodic cost/(benefit)	1.5	143.4	(3.3)
Pension scheme settlement charge	0.0	155.6	0.0
Release of historic cumulative translation adjustments	0.0	(0.7)	0.0
Pension scheme settlement	0.0	138.1	0.0
Tax relating to the recycling of residual reserves	0.0	(34.7)	0.0
Tax relating to historic cumulative translation adjustments	0.0	(11.0)	0.0
Pension scheme settlement	$ 0.0	$ 92.4	$ 0.0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense), Total	Other Nonoperating Income (Expense), Total	Other Nonoperating Income (Expense), Total
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense), Total	Other Nonoperating Income (Expense), Total	Other Nonoperating Income (Expense), Total
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense), Total
Other Nonoperating Income (Expense), Total	$ 0.0	$ (7.3)	$ (6.7)
One Time pension scheme settlement charge	0.0	116.7	0.0
United Kingdom [Member] \| United Kingdom Plan [Member] \| Selling General And Administrative Expenses [Member]
Plan net pension (credit)/charge:
Service cost/(credit)	1.5	(4.9)	3.4
United Kingdom [Member] \| United Kingdom Plan [Member] \| Other Nonoperating Income (Expense) [Member]
Plan net pension (credit)/charge:
Amortization of prior service cost	0.0	0.0	0.5
United Kingdom [Member] \| United Kingdom Plan [Member] \| Pension Scheme Settlement Charge [Member]
Plan net pension (credit)/charge:
Amortization of prior service cost	0.0	16.8	0.0
Recycling of residual reserves	0.0	138.8	0.0
Tax relating to the amortization of prior service cost	0.0	(4.2)	0.0
Tax relating to the recycling of residual reserves	(0.0)	(34.7)	0.0
United Kingdom [Member] \| Reclassification Out of Accumulated Other Comprehensive Income/(Loss) [Member] \| United Kingdom Plan [Member]
Plan net pension (credit)/charge:
Recycling of residual reserves	0.0	138.8	0.0
Release of historic cumulative translation adjustments	0.0	(0.7)	0.0
Pension scheme settlement	0.0	138.1	0.0
Tax relating to the recycling of residual reserves	0.0	(34.7)	0.0
Tax relating to historic cumulative translation adjustments	0.0	(11.0)	0.0
Pension scheme settlement	$ 0.0	$ 92.4	$ 0.0

Consolidated Statements of Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Statement of Stockholders' Equity [Abstract]
Dividend paid, per share	$ 1.71	$ 1.55	$ 1.41

Segment Reporting and Geographical Area Data - Summary of Segment Reporting related to Selling, General and Administrative Expense and Research and Development Expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Segment Reporting Information [Line Items]
Total selling, general and administrative expenses and research and development expenses	$ 336.1	$ 361.8	$ 429.5
Operating Segments [Member] \| Performance Chemicals [Member]
Segment Reporting Information [Line Items]
Total selling, general and administrative expenses and research and development expenses	61.0	65.5	51.1
Operating Segments [Member] \| Fuel Specialties [Member]
Segment Reporting Information [Line Items]
Total selling, general and administrative expenses and research and development expenses	107.4	110.3	105.4
Operating Segments [Member] \| Oilfield Services [Member]
Segment Reporting Information [Line Items]
Total selling, general and administrative expenses and research and development expenses	94.9	115.8	191.8
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Total selling, general and administrative expenses and research and development expenses	$ 72.8	$ 70.2	$ 81.2

Goodwill

12 Months Ended

Dec. 31, 2025

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill

Note 8. Goodwill

The following table analyzes goodwill movement for 2025 and 2024.


(in millions)	Performance Chemicals			Fuel Specialties			Oilfield Services			Total
At December 31, 2023
Gross cost	$	146.9		$	207.6		$	44.8		$	399.3
Accumulated impairment losses		—			—			—			—
Net book amount	$	146.9		$	207.6		$	44.8		$	399.3
Adjustment to the acquired fair values		(3.1	)		—			—			(3.1	)
Exchange effect		(13.7	)		(0.1	)		0.1			(13.7	)
At December 31, 2024
Gross cost	$	130.1		$	207.5		$	44.9		$	382.5
Accumulated impairment losses		—			—			—			—
Net book amount	$	130.1		$	207.5		$	44.9		$	382.5
Additions		—			—			2.0			2.0
Exchange effect		14.4			0.2			(0.1	)		14.5
At December 31, 2025
Gross cost	$	144.5		$	207.7		$	46.8		$	399.0
Accumulated impairment losses		—			—			—			—
Net book amount	$	144.5		$	207.7		$	46.8		$	399.0

The Company’s reporting units, the level at which goodwill is tested for impairment, are consistent with the reportable segments: Performance Chemicals, Fuel Specialties and Oilfield Services.

On December 8, 2023, the Company acquired QGP. This resulted in goodwill of $37.4 million being recognized within our Performance Chemicals segment. In the second quarter of 2024, the fair value of the acquired net assets was revised. As a result of these remeasurement period adjustments, there was an increase of $3.1 million to the fair value of the net assets acquired, with a corresponding decrease to the acquired goodwill.

On July 31, 2025 the Company completed the acquisition of the trade and net assets of Biotechnology Solutions LLC. Biotechnology Solutions LLC is a manufacturer and supplier of biology-based solutions for completion, production and stimulation within Oilfield Services and is based in Oklahoma, USA. The trade and net assets and goodwill has been consolidated into our Oilfield Services business segment. The consideration includes a deferred portion, contingent on future results. The fair value of the consideration is immaterial and has initially resulted in recognition of goodwill of $2.0 million. The goodwill recognized is expected to be deductible for income tax purposes. We have completed our alignment of accounting policies and fair value review on the other net assets acquired.

The components in each segment (including products, markets and competitors) have similar economic characteristics and the segments, therefore, reflect the lowest level at which operations and cash flows can be clearly distinguished, operationally and for financial reporting purposes, from the rest of the Company.

The Company assesses goodwill for impairment on at least an annual basis, initially based on a qualitative assessment to determine whether it is more likely than not that the fair value of a segment is less than the carrying amount. If a potential impairment is identified, then an impairment test is performed.

The Company performed its annual impairment assessment in respect of goodwill as at December 31, 2025, 2024 and 2023. Our impairment assessment concluded that there had been no impairment of goodwill in respect of those reporting units.

We believe that where appropriate the assumptions used in our impairment assessments are reasonable, but that they are judgmental, and variations in any of the assumptions may result in materially different calculations of any potential impairment charges.

- Definition

The entire disclosure for goodwill.

+ References + Details

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Current assets:
Cash and cash equivalents	$ 292.5	$ 289.2
Trade and other accounts receivable (less allowances of $11.8 million and $11.9 million, respectively)	342.3	341.7
Inventories (less allowances of $40.4 million and $34.6 million, respectively):
Finished goods	226.3	197.9
Raw materials	103.0	103.1
Total inventories	329.3	301.0
Prepaid expenses	20.1	21.0
Prepaid income taxes	13.1	3.1
Other current assets	7.3	0.6
Total current assets	1,004.6	956.6
Net property, plant and equipment	286.1	269.7
Operating leases right-of-use assets	52.7	44.8
Goodwill	399.0	382.5
Other intangible assets	67.7	65.4
Deferred tax assets	13.6	9.4
Pension asset	0.0	2.4
Other non-current assets	8.7	3.9
Total assets	1,832.4	1,734.7
Current liabilities:
Accounts payable	174.7	163.8
Accrued liabilities	152.3	169.1
Current portion of operating lease liabilities	15.9	13.9
Current portion of plant closure provisions	4.9	5.0
Current portion of acquisition-related contingent consideration	7.0	0.0
Current portion of accrued income taxes	5.3	19.6
Total current liabilities	360.1	371.4
Operating lease liabilities, net of current portion	36.8	31.0
Plant closure provisions, net of current portion	60.2	55.3
Deferred tax liabilities	19.1	23.5
Pension liabilities and post-employment benefits	13.2	13.1
Acquisition-related contingent consideration	1.3	20.1
Other non-current liabilities	8.8	4.2
Total liabilities	499.5	518.6
Equity:
Common stock, $0.01 par value, authorized 40,000,000 shares, issued 29,554,500 shares	0.3	0.3
Additional paid-in capital	376.5	369.9
Treasury stock (4,776,918 and 4,594,943 shares at cost, respectively)	(115.2)	(93.0)
Retained earnings	1,099.2	1,025.0
Accumulated other comprehensive loss	(34.7)	(91.0)
Total Innospec stockholders' equity	1,326.1	1,211.2
Non-controlling interest	6.8	4.9
Total equity	1,332.9	1,216.1
Total liabilities and equity	$ 1,832.4	$ 1,734.7

Earnings per Share (Tables)

12 Months Ended

Dec. 31, 2025

Earnings Per Share [Abstract]

Summary of Earnings Per Share

Diluted earnings per share includes the effect of options that are dilutive and outstanding during the period. Per share amounts are computed as follows:


	2025		2024		2023
Numerator (in millions):
Net income available to common stockholders	$	116.6	$	35.6	$	139.1
Denominator (in thousands):
Weighted average common shares outstanding		24,880		24,932		24,851
Dilutive effect of stock options and awards		113		187		171
Denominator for diluted earnings per share		24,993		25,119		25,022
Net income per share, basic:	$	4.69	$	1.43	$	5.60
Net income per share, diluted:	$	4.67	$	1.42	$	5.56

Earnings per Share

12 Months Ended

Dec. 31, 2025

Earnings Per Share [Abstract]

Earnings per Share

Note 4. Earnings per Share

Basic earnings per share is based on the weighted average number of common shares outstanding during the period. Diluted earnings per share includes the effect of options that are dilutive and outstanding during the period. Per share amounts are computed as follows:


	2025		2024		2023
Numerator (in millions):
Net income available to common stockholders	$	116.6	$	35.6	$	139.1
Denominator (in thousands):
Weighted average common shares outstanding		24,880		24,932		24,851
Dilutive effect of stock options and awards		113		187		171
Denominator for diluted earnings per share		24,993		25,119		25,022
Net income per share, basic:	$	4.69	$	1.43	$	5.60
Net income per share, diluted:	$	4.67	$	1.42	$	5.56

In 2025, 2024 and 2023 the average number of anti-dilutive options excluded from the calculation of diluted earnings per share were 23,414, 10,413 and 20,334 respectively.

Leases

12 Months Ended

Dec. 31, 2025

Leases [Abstract]

Leases

Note 7. Leases

We have operating leases for toll manufacturing facilities, warehouse storage, land, buildings, plant and equipment. Our leases have remaining lease terms of up to 20 years, some of which include options to terminate the leases within 1 year.

The components of lease expense were as follows:


(in millions)	Twelve Months Ended December 31		Twelve Months Ended December 31		Twelve Months Ended December 31
	2025		2024		2023
Operating lease cost		18.2		17.1		17.9
Short-term lease cost		7.7		8.7		8.1
Total lease cost	$	25.9	$	25.8	$	26.0

Supplemental cash flow information related to leases is as follows:


(in millions)	Twelve Months Ended December 31		Twelve Months Ended December 31		Twelve Months Ended December 31
	2025		2024		2023
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	25.9	$	25.9	$	26.1
Right-of-use assets obtained in exchange for new lease obligations:
Operating leases	$	15.1	$	14.0	$	11.0

Supplemental balance sheet information related to leases is as follows:


(in millions except lease term and discount rate)	December 31, 2025			December 31, 2024
Operating leases:
Operating lease right-of-use assets	$	52.7		$	44.8
Current portion of operating lease liabilities	$	15.9		$	13.9
Operating lease liabilities, net of current portion		36.8			31.0
Total operating lease liabilities	$	52.7		$	44.9
Weighted average remaining lease term:
Operating leases	6.3 years			5.6 years
Weighted average discount rate:
Operating leases		4.1	%		3.8	%

Maturities of lease liabilities were as follows as at December 31, 2025:


(in millions)	Operating Leases
Within one year	$	16.3
Year two		10.0
Year three		8.1
Year four		6.4
Year five		4.9
Thereafter		15.3
Total lease payments		61.0
Less imputed interest		(8.3	)
Total	$	52.7

As of December 31, 2025, additional operating and finance leases that have not yet commenced are $0.7 million.

Maturities of lease liabilities were as follows as at December 31, 2024:


(in millions)	Operating Leases
Within one year	$	14.3
Year two		9.8
Year three		5.7
Year four		5.1
Year five		3.9
Thereafter		11.7
Total lease payments		50.5
Less imputed interest		(5.6	)
Total	$	44.9

As of December 31, 2024, additional operating and finance leases that have not yet commenced are $0.3 million.

Recently Issued Accounting Pronouncements

12 Months Ended

Dec. 31, 2025

Accounting Changes and Error Corrections [Abstract]

Recently Issued Accounting Pronouncements

Note 20. Recently Issued Accounting Pronouncements

In December 2023, the Financial Accounting Standards Board issued Accounting Standards Update (ASU) No. 2023-09, Improvements to Income Tax Disclosures (Topic 740). This guidance establishes new income tax disclosure requirements in addition to modifying and eliminating certain existing guidance. Under the new guidance, entities must consistently categorize and provide greater disaggregation of information in the rate reconciliation. They must also further disaggregate income taxes paid. This ASU was effective for fiscal years beginning after December 15, 2024. Early adoption was permitted. The Company adopted the guidance on a retrospective basis for the period ending December 31, 2025, and the adoption of this ASU is demonstrated within Note 11 of the Notes to the Consolidated Financial Statements.

- Definition

The entire disclosure for change in accounting principle. Includes, but is not limited to, nature, reason, and method of adopting amendment to accounting standards or other change in accounting principle.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 9
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-9

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 17
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480336/718-10-65-17

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 17
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480336/718-10-65-17

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476173/280-10-65-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 7
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-7

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 60
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476176/805-60-65-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 848
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483550/848-10-65-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 848
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483550/848-10-65-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 848
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483550/848-10-65-1

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480016/944-40-65-2

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480016/944-40-65-2

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(iii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480016/944-40-65-2

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(iv)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480016/944-40-65-2

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (h)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480016/944-40-65-2

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 5
-Subparagraph (SAB Topic 11.M.Q2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480530/250-10-S99-5

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (i)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480528/815-20-65-6

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-1

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479654/326-10-65-4

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (e)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479654/326-10-65-4

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480530/250-10-S99-6

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (f)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481538/470-20-65-4

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481538/470-20-65-4

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-1

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Topic 250
-Publisher FASB
-URI https://asc.fasb.org/250/tableOfContent

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

+ Details

Income Taxes - Components of Income Tax Expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Current:
Federal	$ 4.5	$ 16.9	$ 12.4
State and local	1.7	2.9	0.2
Foreign	24.3	26.2	18.6
Total Current Income Tax	30.5	46.0	31.2
Deferred:
Federal	(7.7)	(4.1)	5.2
State and local	(0.3)	(0.5)	0.3
Foreign	(1.0)	(35.8)	(1.4)
Total Deferred Income Tax	(9.0)	(40.4)	4.1
Total:
Federal	(3.2)	12.8	17.6
State and local	1.4	2.4	0.5
Foreign	23.3	(9.6)	17.2
Total Income Tax expense	$ 21.5	$ 5.6	$ 35.3

Derivative Instruments and Risk Management

12 Months Ended

Dec. 31, 2025

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivative Instruments and Risk Management

Note 15. Derivative Instruments and Risk Management

The Company has limited involvement with derivative instruments and does not trade them. The Company does use derivatives to manage certain interest rate, foreign currency exchange rate, raw material cost exposures and greenhouse gases emission allowances, as the need arises.

The Company has previously entered into interest rate swap contracts to reduce interest rate risk on its core debt. As at December 31, 2025 and 2024, there were no interest rate swaps in place. Interest rate swaps were previously in place to hedge interest rate risk on the term loan for a notional value that matched the repayment profile of the term loan.

The Company enters into various foreign currency forward exchange contracts to minimize currency exchange rate exposure from expected future cash flows. As at December 31, 2025, foreign currency forward exchange contracts with a notional value of $238.9 million were in place (December 31, 2024 $212.8 million), with maturity dates of up to twelve months from the date of inception. These foreign currency forward exchange contracts have not been designated as hedging instruments, and their impact on the income statement for 2025 was a loss of $3.1 million (2024 – gain $5.3 million).

As at December 31, 2025 and 2024, the Company did not hold any raw material derivatives.

The Company participates in the new United Kingdom Emissions Trading Scheme (“UK ETS”) which was launched on January 1, 2021. Emissions trading schemes work on the ‘cap and trade’ principle, where a cap is set on the total amount of certain greenhouse gases that can be emitted by sectors covered by the scheme. This limits the total amount of carbon that can be emitted. Within this cap, participants receive free allowances and/or buy emission allowances at auction or on the secondary market which they can trade with other participants as needed. As at December 31, 2025, the Company held UK ETS credits of $3.2 million (December 31, 2024 – $3.9 million).

The Company sells a range of specialty chemicals to major oil refiners and chemical companies throughout the world. Credit limits, ongoing credit evaluation and account monitoring procedures are intended to minimize bad debt risk. Collateral is not generally required.

- Definition

The entire disclosure for derivative instruments and hedging activities including, but not limited to, risk management strategies, non-hedging derivative instruments, assets, liabilities, revenue and expenses, and methodologies and assumptions used in determining the amounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 182
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480401/815-10-55-182

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 185
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480401/815-10-55-185

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 184
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480401/815-10-55-184

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 181
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480401/815-10-55-181

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4K
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4K

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4K
-Subparagraph (a)(5)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4K

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4K
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4K

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4K
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4K

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4K
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4K

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4H
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4H

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4H
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4H

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 15
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480960/815-15-50-3

Reference 13: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 183
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480401/815-10-55-183

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4K
-Subparagraph (a)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4K

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4K
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4K

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4K
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4K

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4I
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4I

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4F
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4F

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-2

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-2

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)(iii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-2

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)(ii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-2

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-2

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1B

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/815/tableOfContent

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480237/815-40-50-5

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5C
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-5C

+ Details

Plant Closure Provisions - Movements in Plant Closure and Restructuring Provisions (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Restructuring and Related Activities [Abstract]
Beginning Balance	$ 60.3	$ 61.6	$ 57.2
Charge for the period	5.6	4.7	8.9
Utilized in the period	(5.8)	(3.8)	(4.9)
Exchange effect	5.0	(2.2)	0.4
Ending Balance	65.1	60.3	61.6
Due within one year	(4.9)	(5.0)	(4.6)
Due after one year	$ 60.2	$ 55.3	$ 57.0

Segment Reporting and Geographical Area Data - Segment Reporting (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Segment Reporting Information [Line Items]
Net sales	$ 1,778.0	$ 1,845.4	$ 1,948.8
Gross profit	492.4	542.9	591.1
Adjustment to fair value of contingent consideration	15.9	(3.4)	0.0
Restructuring charge	0.9	0.0	0.0
Impairment of property, plant and equipment	22.9	0.0	0.0
Impairment of intangible assets	19.1	0.0	0.0
Profit on disposal of property, plant and equipment	0.2	0.2	0.0
Operating income/(expense)	129.5	177.9	161.6
Identifiable assets at year end	1,832.4	1,734.7
Oilfield Services [Member]
Segment Reporting Information [Line Items]
Net sales			265.2
Operating Segments [Member]
Segment Reporting Information [Line Items]
Adjustment to fair value of contingent consideration	15.9	(3.4)	0.0
Restructuring charge	(0.9)	0.0	0.0
Impairment of property, plant and equipment	(22.9)	0.0	0.0
Impairment of intangible assets	(19.1)	0.0	0.0
Profit on disposal of property, plant and equipment	0.2	0.2	0.0
Operating Segments [Member] \| Performance Chemicals [Member]
Segment Reporting Information [Line Items]
Net sales	681.4	653.7	561.6
Gross profit	122.0	148.4	105.6
Operating income/(expense)	61.0	82.9	54.5
Identifiable assets at year end	602.0	598.3
Operating Segments [Member] \| Fuel Specialties [Member]
Segment Reporting Information [Line Items]
Net sales	701.5	701.1	695.9
Gross profit	252.2	239.9	215.1
Operating income/(expense)	144.8	129.6	109.7
Identifiable assets at year end	625.5	553.8
Operating Segments [Member] \| Oilfield Services [Member]
Segment Reporting Information [Line Items]
Net sales	395.1	490.6	691.3
Gross profit	118.2	154.6	270.4
Operating income/(expense)	23.3	38.8	78.6
Identifiable assets at year end	212.2	272.5
Operating Segments [Member] \| Personal Care [Member] \| Performance Chemicals [Member]
Segment Reporting Information [Line Items]
Net sales	409.2	390.0	352.7
Operating Segments [Member] \| Home Care [Member] \| Performance Chemicals [Member]
Segment Reporting Information [Line Items]
Net sales	109.0	106.6	86.8
Operating Segments [Member] \| Other [Member] \| Performance Chemicals [Member]
Segment Reporting Information [Line Items]
Net sales	163.2	157.1	122.1
Operating Segments [Member] \| Refinery and Performance [Member] \| Fuel Specialties [Member]
Segment Reporting Information [Line Items]
Net sales	509.4	517.4	540.6
Operating Segments [Member] \| Other [Member] \| Fuel Specialties [Member]
Segment Reporting Information [Line Items]
Net sales	192.1	183.7	155.3
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Corporate costs	(72.8)	(70.2)	$ (81.2)
Identifiable assets at year end	$ 392.7	$ 310.1

Plant Closure Provisions (Tables)

12 Months Ended

Dec. 31, 2025

Restructuring and Related Activities [Abstract]

Movements in Plant Closure and Restructuring Provisions

Movements in the provisions are summarized as follows:


(in millions)	2025			2024			2023
Total at January 1	$	60.3		$	61.6		$	57.2
Charge for the period		5.6			4.7			8.9
Utilized in the period		(5.8	)		(3.8	)		(4.9	)
Exchange effect		5.0			(2.2	)		0.4
Total at December 31		65.1			60.3			61.6
Due within one year		(4.9	)		(5.0	)		(4.6	)
Due after one year	$	60.2		$	55.3		$	57.0

Leases (Tables)

12 Months Ended

Dec. 31, 2025

Leases [Abstract]

Components of Lease Expense

The components of lease expense were as follows:


(in millions)	Twelve Months Ended December 31		Twelve Months Ended December 31		Twelve Months Ended December 31
	2025		2024		2023
Operating lease cost		18.2		17.1		17.9
Short-term lease cost		7.7		8.7		8.1
Total lease cost	$	25.9	$	25.8	$	26.0

Supplemental Cash Flow Information Related to Leases

Supplemental cash flow information related to leases is as follows:


(in millions)	Twelve Months Ended December 31		Twelve Months Ended December 31		Twelve Months Ended December 31
	2025		2024		2023
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	25.9	$	25.9	$	26.1
Right-of-use assets obtained in exchange for new lease obligations:
Operating leases	$	15.1	$	14.0	$	11.0

Supplemental Balance Sheet Information Related to Leases

Supplemental balance sheet information related to leases is as follows:


(in millions except lease term and discount rate)	December 31, 2025			December 31, 2024
Operating leases:
Operating lease right-of-use assets	$	52.7		$	44.8
Current portion of operating lease liabilities	$	15.9		$	13.9
Operating lease liabilities, net of current portion		36.8			31.0
Total operating lease liabilities	$	52.7		$	44.9
Weighted average remaining lease term:
Operating leases	6.3 years			5.6 years
Weighted average discount rate:
Operating leases		4.1	%		3.8	%

Maturities of Lease Liabilities

Maturities of lease liabilities were as follows as at December 31, 2025:


(in millions)	Operating Leases
Within one year	$	16.3
Year two		10.0
Year three		8.1
Year four		6.4
Year five		4.9
Thereafter		15.3
Total lease payments		61.0
Less imputed interest		(8.3	)
Total	$	52.7

As of December 31, 2025, additional operating and finance leases that have not yet commenced are $0.7 million.

Maturities of lease liabilities were as follows as at December 31, 2024:


(in millions)	Operating Leases
Within one year	$	14.3
Year two		9.8
Year three		5.7
Year four		5.1
Year five		3.9
Thereafter		11.7
Total lease payments		50.5
Less imputed interest		(5.6	)
Total	$	44.9

Share-Based Compensation Plans - Additional Information (Detail) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2025 USD ($) StockPlan $ / shares shares	Dec. 31, 2024 USD ($) $ / shares	Dec. 31, 2023 USD ($) $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option compensation	$ 8.1	$ 8.5	$ 8.0
Maximum percentage of stock options granted	200.00%
Total compensation cost related to non-vested stock options not yet recognized	$ 17.7
Expected compensation cost recognized over the weighted-average period	1 year 9 months 18 days
Accrued liabilities	$ 152.3	169.1
Weighted Average Grant-Date Fair Value, Vested \| $ / shares	$ 77.8
Share-Based Payment Arrangement, Expense, after Tax	$ 1.0	0.1	0.3
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration term for stock granted	10 years
Aggregate number of shares of common stock reserved for issuance which can be granted \| shares	2,550,000
Number of stock option plans \| StockPlan	2
Stock option compensation	$ 8.1	8.5	8.0
Employee Stock Option \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of stock vesting period	2 years
Employee Stock Option \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of stock vesting period	5 years
Stock Equivalent Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration term for stock granted	10 years
Total intrinsic value exercised	$ 13.5	22.4
Accrued liabilities	12.5
Compensation cost	$ 1.8	$ 6.5	$ 13.5
Weighted Average Grant-Date Fair Value, Vested \| $ / shares	$ 107.1	$ 130.3	$ 94.4
Total intrinsic value of options outstanding	$ 34.4
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Intrinsic Value	3.0
ProceedsFromStockOptionsExercised	6.2	$ 12.8
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested in Period, Fair Value	$ 16.4	$ 16.4
Stock Equivalent Units [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of stock vesting period	6 months
Stock Equivalent Units [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of stock vesting period	5 years

Segment Reporting and Geographical Area Data - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2025 USD ($) Segment	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Number of reportable segments \| Segment	3
Revenue from Contract with Customer, Excluding Assessed Tax	$ 1,778.0	$ 1,845.4	$ 1,948.8
Segment Reporting, CODM, Individual Title and Position or Group Name [Extensible Enumeration]	President And Chief Executive Officer [Member]
Segment Reporting, CODM, Profit (Loss) Measure, How Used, Description	The CODM evaluates the performance of the Company’s segments and makes strategic decisions relating to the Company's allocation of resources, based on the segments' monthly gross profit and operating income.
Oilfield Services [Member]
Revenue from Contract with Customer, Excluding Assessed Tax			$ 265.2
Percentage of Revenue from Contract With Customer	10.00%	10.00%	13.60%

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476153/220-40-55-4

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476153/220-40-55-14

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 41
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-41

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-42

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-7

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 270
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482964/270-10-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (ee)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 8: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 9: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 924
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479941/924-10-S99-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-5

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 30
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-30

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-22

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 40
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-40

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-22

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-4

+ Details

Commitments and Contingencies

12 Months Ended

Dec. 31, 2025

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Note 16. Commitments and Contingencies

Asset retirement obligations and environmental remediation liabilities

Commitments in respect of asset retirement obligations and environmental remediation liabilities are disclosed in Note 13 of the Notes to the Consolidated Financial Statements.

Capital commitments

The estimated additional cost to complete work in progress at December 31, 2025 is $55.0 million (2024 – $35.4 million).

Internally developed software

The estimated additional cost to complete work in progress at December 31, 2025 is $4.2 million (2024 – $29.5 million).

Contingencies

Legal matters

We are involved from time to time in claims and legal proceedings that result from, and are incidental to, the conduct of our business including business and commercial litigation, employee and product liability claims.

As reported in the 2023 Form 10-K, we have incurred financial losses and lodged a civil and criminal legal claim related to a misappropriation of inventory in Brazil. At the time of filing, there have been no significant developments to report in relation to the claims being made. Consistent with prior quarters, a corresponding asset for the potential legal or insurance recoveries has not been recorded for the resulting financial losses arising from this matter.

In addition, unrelated to the Brazil matter, in the unlikely event there are an unexpectedly large number of individual claims or proceedings with an adverse resolution, this could in the aggregate have a material adverse effect on the results of operations for a particular year or quarter.

Guarantees

The Company and certain of the Company’s consolidated subsidiaries are contingently liable for certain obligations of affiliated companies primarily in the form of guarantees of debt and performance under contracts entered into as a normal business practice. This includes guarantees of non-U.S. excise taxes and customs duties. As at December 31, 2025, such guarantees which are not recognized as liabilities in the consolidated financial statements amounted to $6.0 million (December 31, 2024 – $6.8 million). The remaining terms of the fixed maturity guarantees vary from approximately 3 months to 7 years, with some further guarantees having no fixed expiry date.

Under the terms of the guarantee arrangements, generally the Company would be required to perform should the affiliated company fail to fulfill its obligations under the arrangements. In some cases, the guarantee arrangements have recourse provisions that would enable the Company to recover any payments made under the terms of the guarantees from securities held of the guaranteed parties’ assets.

The Company and its affiliates have numerous long-term sales and purchase commitments in their various business activities, which are expected to be fulfilled with no adverse consequences material to the Company.

Income Taxes - Factors Effecting Effective Tax Rate from U.S. Federal Statutory Rate (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
U.S. federal statutory tax rate	$ 29.0	$ 8.7	$ 36.6
State and local income taxes, net of federal income tax effect	$ 1.7	$ 2.7	$ 1.0
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. federal statutory tax rate	21.00%	21.00%	21.00%
State and local income taxes, net of federal income tax effect	1.20%	6.60%	0.60%
Effect of cross-border tax laws:
Global intangible low-taxed income, net of foreign tax credit	$ 0.8	$ 4.3	$ (0.2)
Subpart F income, net of foreign tax credit	0.0	1.2	0.2
Incentive for foreign derived intangible income	(0.5)	(1.9)	(4.5)
Tax on unremitted foreign earnings	2.1	0.8	2.4
Other	0.1	0.3	0.0
Tax credits	$ (0.5)	$ (0.9)	$ (1.0)
Effect of cross-border tax laws: Percent
Global intangible low-taxed income, net of foreign tax credit, Percent	0.60%	10.40%	(0.10%)
Subpart F income, net of foreign tax credit, Percent	0.00%	2.90%	0.10%
Incentive for foreign derived intangible income, Percent	(0.40%)	(4.60%)	(2.60%)
Tax on unremitted foreign earnings, Percent	1.50%	1.90%	1.40%
Other, Percent	0.10%	0.70%	0.00%
Tax credits, Percent	(0.40%)	(2.20%)	(0.60%)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amount [Abstract]
Nondeductible officer compensation		$ 2.0	$ 1.8
Other	$ 0.7	(0.9)	(0.2)
Changes in unrecognized tax benefits	0.0	(10.1)	1.3
Tax impact of internal reorganizations	(9.5)	0.0	0.0
Total Income Tax expense	$ 21.5	$ 5.6	$ 35.3
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent [Abstract]
Nondeductible officer compensation, Percent		4.90%	1.00%
Other, Percent	0.50%	(2.10%)	(0.10%)
Changes in unrecognized tax benefits, Percent	0.00%	(24.50%)	0.70%
Tax impact of internal reorganizations, Percent	(6.90%)	0.00%	0.00%
Total	15.60%	13.60%	20.20%
Brazil [Member]
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Changes in valuation allowance		$ 2.7
Adjustment to contingent consideration	$ (3.2)	0.7
Foreign tax rate differential			$ (1.8)
Other	$ (1.2)	$ 0.8	$ 0.3
Foreign tax effects:
Changes in valuation allowance		6.60%
Adjustment to contingent consideration	(2.30%)	1.70%
Foreign tax rate differential			(1.00%)
Other	(0.80%)	1.90%	0.20%
Germany [Member]
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Foreign tax rate differential		$ 0.7
Other		$ (0.1)
Foreign tax effects:
Foreign tax rate differential		1.70%
Other		(0.20%)
Italy [Member]
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Italy		$ 0.6
Foreign tax effects:
Italy27/01/2026		1.50%
United Kingdom [Member]
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Foreign tax rate differential	$ 2.1	$ (3.4)	$ 1.3
Other	0.4	0.4	0.5
Foreign currency transactions			(2.6)
Innovation incentives	$ (3.2)	$ (3.2)	$ (1.5)
Foreign tax effects:
Foreign tax rate differential	1.50%	(8.30%)	0.70%
Other	0.30%	1.00%	0.30%
Foreign currency transactions			(1.50%)
Innovation Incentives	(2.30%)	(7.80%)	(0.90%)
Other Jurisdiction [Member]
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Foreign tax rate differential	$ 2.7	$ 0.2	$ 1.7
Foreign tax effects:
Foreign tax rate differential	2.00%	0.50%	1.00%

Accounting Policies - Estimated Useful Lives of Major Classes of Assets (Detail)	Dec. 31, 2025
Technology [Member] \| Minimum [Member]
Other Intangible Assets [Line Items]
finite-lived intangible asset, useful life	10 years
Technology [Member] \| Maximum [Member]
Other Intangible Assets [Line Items]
finite-lived intangible asset, useful life	17 years
Customer lists [Member] \| Minimum [Member]
Other Intangible Assets [Line Items]
finite-lived intangible asset, useful life	7 years
Customer lists [Member] \| Maximum [Member]
Other Intangible Assets [Line Items]
finite-lived intangible asset, useful life	15 years
Brand Names [Member] \| Minimum [Member]
Other Intangible Assets [Line Items]
finite-lived intangible asset, useful life	5 years
Brand Names [Member] \| Maximum [Member]
Other Intangible Assets [Line Items]
finite-lived intangible asset, useful life	10 years
Product Rights [Member] \| Minimum [Member]
Other Intangible Assets [Line Items]
finite-lived intangible asset, useful life	9 years
Product Rights [Member] \| Maximum [Member]
Other Intangible Assets [Line Items]
finite-lived intangible asset, useful life	10 years
Internally Developed Software [Member] \| Minimum [Member]
Other Intangible Assets [Line Items]
finite-lived intangible asset, useful life	3 years
Internally Developed Software [Member] \| Maximum [Member]
Other Intangible Assets [Line Items]
finite-lived intangible asset, useful life	12 years
Marketing Related [Member]
Other Intangible Assets [Line Items]
finite-lived intangible asset, useful life	11 years

Income Taxes - Sources of Income before Income Taxes (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Domestic	$ 25.9	$ 90.2	$ 95.2
Foreign	112.2	(49.0)	79.2
Income before income tax expense	$ 138.1	$ 41.2	$ 174.4

- Definition

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476153/220-40-55-4

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476153/220-40-55-21

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476153/220-40-55-14

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 235
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478671/942-235-S50-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 235
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-05(b)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477314/942-235-S99-1

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-22

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 48
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482785/280-10-55-48

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 30
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-30

Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 270
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482964/270-10-50-1

Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (ee)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 12: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(11))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 14: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 31
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-31

Reference 15: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(10))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Reference 16: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(15))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1

+ Details

Related Party Transactions - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Smith, Gambrell & Russell, LLP [Member]
Related Party Transaction [Line Items]
Fees incured from Smith, Gambrell & Russell		$ 200,000	$ 300,000
Other Liabilities		0
European Metal Recycling Limited [Member]
Related Party Transaction [Line Items]
Other Liabilities	$ 0	0
Tendering process to select best buyer of scrap metal			100,000
European Metal Recycling Limited [Member] \| Maximum [Member]
Related Party Transaction [Line Items]
Tendering process to select best buyer of scrap metal	100,000	100,000
Advan Six [Member]
Related Party Transaction [Line Items]
Other Liabilities	0	0
Tendering process to select best buyer of scrap metal	$ 0	$ 0	$ 400,000

- Definition

Amount of liabilities classified as other.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(15))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 480
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 64
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481620/480-10-55-64

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 605
-Name Accounting Standards Codification
-Section 55
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477548/944-605-55-14

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 605
-Name Accounting Standards Codification
-Section 55
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477548/944-605-55-11

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(15))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Topic 946
-SubTopic 830
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479168/946-830-55-12

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04(12)(b)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04(12)(b)(3))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1

Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04(12)(b)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1

Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(17))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

+ Details

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483326/850-10-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483326/850-10-50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483326/850-10-50-3

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(k)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(k)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481990/310-10-45-13

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(c)(2)(i))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(c)(2)(ii))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(g)(3))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1

+ Details

Reclassifications out of Accumulated Other Comprehensive Loss

12 Months Ended

Dec. 31, 2025

Equity [Abstract]

Reclassifications out of Accumulated Other Comprehensive Loss

Note 19. Reclassifications out of Accumulated Other Comprehensive Loss

Reclassifications out of accumulated other comprehensive loss (“AOCL”) for 2025 were:


(in millions)
Details about AOCL Components	Amount Reclassified from AOCL		Affected Line Item in the Statement where Net Income is Presented
Defined benefit pension plan items:
Amortization of prior service cost	$	—	See (1) below
Amortization of actuarial net losses		—	See (1) below
		—	Total before tax
		—	Income tax expense
Total reclassifications	$	—	Net of tax

(1)

These items are included in the computation of net periodic pension cost. See Note 10 of the Notes to the Consolidated Financial Statements for additional information.

Changes in AOCL for 2025, net of tax, were:


(in millions)	Defined Benefit Pension Plan Items		Cumulative Translation Adjustments			Total
Balance at December 31, 2024	$	—	$	(91.0	)	$	(91.0	)
Other comprehensive income/(losses) before reclassifications		—		55.4			55.4
Amounts reclassified from AOCL		—		—			—
Actuarial net losses arising during the year		0.9		—			0.9
Net current period other comprehensive income/(losses)		0.9		55.4			56.3
Balance at December 31, 2025	$	0.9	$	(35.6	)	$	(34.7	)

Reclassifications out of AOCL for 2024 were:


(in millions)
Details about AOCL Components	Amount Reclassified from AOCL			Affected Line Item in the Statement where Net Income is Presented
Defined benefit pension plan items:
Amortization of prior service cost	$	8.4		See (1) below
Amortization of actuarial net losses		(0.2	)	See (1) below
Pension scheme settlement		138.1		See (1) below
		146.3		Total before tax
		(47.8	)	Income tax expense
Total reclassifications	$	98.5		Net of tax

(1)

These items are included in the computation of net periodic pension cost. See Note 10 of the Notes to the Consolidated Financial Statements for additional information.

Changes in AOCL for 2024, net of tax, were:


(in millions)	Defined Benefit Pension Plan Items			Cumulative Translation Adjustments			Total
Balance at December 31, 2023	$	(77.2	)	$	(70.9	)	$	(148.1	)
Other comprehensive income/(losses) before reclassifications		—			(20.1	)		(20.1	)
Amounts reclassified from AOCL		98.5			—			98.5
Actuarial net losses arising during the year		(21.3	)		—			(21.3	)
Net current period other comprehensive income/(losses)		77.2			(20.1	)		57.1
Balance at December 31, 2024	$	—		$	(91.0	)	$	(91.0	)

Leases - Supplemental Cash Flow Information Related to Leases (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 25.9	$ 25.9	$ 26.1
Right-of-use assets obtained in exchange for new lease obligations:
Operating leases	$ 15.1	$ 14.0	$ 11.0

Long-Term Debt - Additional Information (Detail) - USD ($)			12 Months Ended
	May 20, 2024	May 31, 2023	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Due date of revolving credit	May 31, 2028
Capitalized contract cost net			$ 300,000
Capitalized costs amortization period			May 31, 2028
Deferred finance costs, net			$ 700,000	$ 1,100,000
Amortization of deferred finance costs			$ 400,000	$ 400,000	$ 400,000
Weighted average rate of interest on borrowings			0.00%	0.00%
Payments of interest on long-term debt			$ 0	$ 0	0
Net cash outflows in respect of refinancing costs			0	300,000	1,400,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility cumulative drawn down			$ 0	0
Due date of revolving credit		May 30, 2027	Sep. 26, 2019
Line of credit facility maximum borrowing capacity		$ 250,000,000
Expiration period		4 years
Repayment on credit facility			$ 0	$ 0	$ 0
Revolving Credit Facility [Member] \| Accordion Feature [Member]
Debt Instrument [Line Items]
Line of credit facility maximum borrowing capacity		$ 125,000,000

Income Taxes - Details of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Deferred tax assets:
Stock compensation	$ 3.3	$ 3.7
Net operating loss carry forwards	8.2	8.8
Other intangible assets	15.6	4.8
Accretion expense	3.2	3.2
Restructuring provision	1.4	1.5
Employee related liabilities	4.6	9.2
Foreign tax credits	3.0	2.1
Operating lease liabilities	12.9	11.1
Inventory provisions	9.4	9.0
Pensions	1.2	0.5
Carried forward interest deductions	2.7	1.4
Bad debt reserves	1.1	1.4
Research and experimental expenditure	6.1	8.3
Other	5.7	3.4
Subtotal	78.4	68.4
Less valuation allowance	(2.8)	(2.4)
Total net deferred tax assets	75.6	66.0
Deferred tax liabilities:
Property, plant and equipment	(27.0)	(29.5)
Intangible assets including goodwill	(31.2)	(31.6)
Customer relationships	(1.0)	(1.7)
Unremitted overseas earnings	(7.2)	(5.1)
Right-of-use assets	(12.9)	(10.7)
Other	(1.8)	(1.5)
Total deferred tax liabilities	(81.1)	(80.1)
Net deferred tax liability	(5.5)	(14.1)
Deferred tax assets	13.6	9.4
Deferred tax liabilities	(19.1)	(23.5)
Net deferred tax liability	$ (5.5)	$ (14.1)

Plant Closure Provisions - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Restructuring Cost and Reserve [Line Items]
Expenditure	$ 5.8	$ 3.8	$ 4.9
Remediation [Member]
Restructuring Cost and Reserve [Line Items]
Accretion expense recognized	3.6
Remediation charge for changes in the scope and cost of future remediation activities	$ 2.0

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References + Details

Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2025

Accounting Policies [Abstract]

Estimated Useful Lives of Major Classes of Depreciable Assets

The estimated useful lives of the major classes of depreciable assets are as follows:


Buildings		7 to 25 years
Equipment		3 to 10 years

Estimated Useful Lives of Major Classes of Assets

The estimated useful lives of the major classes of assets are as follows:


Technology		10 to 17 years
Customer lists		7 to 15 years
Brand names		5 to 10 years
Product rights		9 to 10 years
Internally developed software		3 to 12 years
Marketing related		11 years

Stockholders' Equity

12 Months Ended

Dec. 31, 2025

Equity [Abstract]

Stockholders' Equity

Note 17. Stockholders’ Equity


	Common Stock						Treasury Stock
(number of shares in thousands)	2025		2024		2023		2025			2024			2023
At January 1		29,554.5		29,554.5		29,554.5		4,595			4,687			4,789
Exercise of options		—		—		—		(82	)		(97	)		(113	)
Stock purchases		—		—		—		264			5			11
At December 31		29,554.5		29,554.5		29,554.5		4,777			4,595			4,687

At December 31, 2025, the Company had authorized common stock of 40,000,000 shares (2024 - 40,000,000).

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-8A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-14

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477968/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477968/946-235-50-2

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478448/946-505-50-6

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480237/815-40-50-6

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/505/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-14

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-14

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-16

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

+ Details

Long-Term Debt

12 Months Ended

Dec. 31, 2025

Debt Disclosure [Abstract]

Long-Term Debt

Note 12. Long-Term Debt

As at December 31, 2025 and 2024, the Company has not drawn down on its revolving credit facility. During 2025, 2024 and 2023, the Company did not draw down or repay any borrowing on its revolving credit facility.

On May 31, 2023, Innospec Inc. and certain subsidiaries of the Company (together with the Company, the “Borrowers”) entered into a Multicurrency Revolving Facility Agreement with various lenders (the “Agreement”) which replaces the Company’s credit facility agreement dated September 26, 2019. The Agreement provides for a $250.0 million four-year multicurrency revolving loan facility available to the Borrowers (the “Facility”). The Agreement also contains an accordion feature whereby the Company may elect to increase the total available borrowings by an aggregate amount of up to $125.0 million. The termination date of the Facility is May 30, 2027, but the Agreement includes an option for the Company to request an extension of the Facility for a further year.

Effective as of May 20, 2024, the termination date of the Facility was extended from May 30, 2027 to May 31, 2028 in accordance with the terms of the Company’s multicurrency revolving facility agreement (the “Facility Agreement”). No other terms of the Facility Agreement or the Facility were modified. The Company paid a customary extension fee in connection with the extension of the Facility as contemplated by the Facility Agreement. As a consequence, the Company has capitalized a further $0.3 million of costs relating to the new Agreement which are to be amortized over the period to May 31, 2028.


(in millions)	2025			2024
Gross cost at January 1	$	1.7		$	1.4
Capitalized in the year		—			0.3
		1.7			1.7

Accumulated amortization at January 1	$	(0.6	)	$	(0.2	)
Amortization in the year		(0.4	)		(0.4	)
	$	(1.0	)	$	(0.6	)

Net book value at December 31	$	0.7		$	1.1

Amortization expense was $0.4 million, $0.4 million and $0.4 million in 2025, 2024 and 2023, respectively. The charge is included in interest expense, see Note 2 of the Notes to the Consolidated Financial Statements.

The obligations of the Company under the credit facility are secured obligations and guaranteed by certain subsidiaries of the Company. Amounts available under the revolving facility may be borrowed in U.S. dollars, Euros, British pounds and other freely convertible currencies.

The Company’s credit facility contains restrictive clauses which may constrain our activities and limit our operational and financial flexibility. The facility obliges the lenders to comply with a request for utilization of finance unless there is an event of default outstanding. Events of default are defined in the credit facility and include a material adverse change to our assets, operations or financial condition. The facility contains a number of restrictions that limit our ability, among other things, and subject to certain limited exceptions, to incur additional indebtedness, pledge our assets as security, guarantee obligations of third parties, make investments, undergo a merger or consolidation, dispose of assets, or materially change our line of business.

In addition, the credit facility contains terms which, if breached, would result in it becoming repayable on demand. It requires, among other matters, compliance with the following financial covenant ratios measured on a quarterly basis: (1) the ratio of net debt to EBITDA shall not be greater than 3.5:1 and (2) the ratio of EBITDA to net interest shall not be less than 4.0:1. Management has determined that the Company has not breached these covenants throughout the period to December 31, 2025 and does not expect to breach these covenants for the next 12 months.

The weighted average rate of interest on borrowings was 0.00% at December 31, 2025 and 0.00% at December 31, 2024. Payments of interest on long-term debt were $0.0 million, $0.0 million and $0.0 million in 2025, 2024 and 2023, respectively.

The net cash outflows in respect of refinancing costs were $0.0 million, $0.3 million and $1.4 million in 2025, 2024 and 2023, respectively.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-8A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(c))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481544/470-10-50-6

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481544/470-10-50-6

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477092/405-40-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477092/405-40-50-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477092/405-40-50-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477092/405-40-50-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477092/405-40-50-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 470
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/470/tableOfContent

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482925/835-30-45-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1C

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1C

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1C

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1E

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1I

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1I

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1I

+ Details

Share-Based Compensation Plans - Summary of Transactions of The Share Based Compensation Plans (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of shares, Begining balance	574,671	431,297
Number of shares, Granted	166,337
Number of shares, Vested	(210,227)
Number of shares, Exercised	(139,904)
Number of shares, Forfeited	(11,831)
Number of shares, Cancelled	(87,653)
Number of shares , Ending balance		574,671
Weighted Average Grant-Date Fair Value , Begining balance	$ 86.2
Weighted Average Grant-Date Fair Value, Granted	107.1
Weighted Average Grant-Date Fair Value, Vested	77.8
Weighted Average Grant-Date Fair Value, Forfeited	72.5
Weighted Average Grant-Date Fair Value, Cancelled	31.3
Weighted Average Grant-Date Fair Value, Ending balance	$ 109.5	$ 86.2
Outstanding at December 31, 2023	619,705
Number of shares, Forfeited	(17,281)
Outstanding at December 31, 2024	541,204	619,705
Exercisable at December 31, 2024	109,907
Outstanding, Weighted Average Exercise Price, Beginning balance	$ 23.5
Granted, Weighted Average Exercise Price	0
Exercised, Weighted Average Exercise Price	3.5
Forfeited, Weighted Average Exercise Price	34
Cancelled, Weighted Average Exercise Price	75.7
Outstanding, Weighted Average Exercise Price, Ending balance	12.7	$ 23.5
Weighted Average Exercise price , Exercisable	$ 49.1
Weighted-Average Remaining Contractual Term, Outstanding	2 years 1 month 6 days
Weighted-Average Remaining Contractual Term, Exercisable	2 years 8 months 12 days

Income Taxes - Factors Effecting Effective Tax Rate from U.S. Federal Statutory Rate (Parenthetical) (Details)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Effect of tax rate portion in state tax	50.00%	50.00%	50.00%

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Other Commitments [Line Items]
Guarantees	$ 6.0	$ 6.8
Minimum [Member]
Other Commitments [Line Items]
Fixed maturity guarantee remaining term	3 months
Maximum [Member]
Other Commitments [Line Items]
Fixed maturity guarantee remaining term	7 years
Additional Cost To Complete Wip [Member]
Other Commitments [Line Items]
Capital commitments	$ 55.0	35.4
Additional Cost To Complete Wip [Member] \| Computer Software, Intangible Asset [Member]
Other Commitments [Line Items]
Capital commitments	$ 4.2	$ 29.5

Income Taxes - Cash Paid for Income Taxes (Net of Refunds) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Tax Paid, by Individual Jurisdiction [Line Items]
Federal	$ 26.1	$ 27.5	$ 27.5
State and local	3.1	1.4	4.7
Income Tax Paid, Foreign, after Refund Received [Abstract]
Foreign	21.8	22.8	22.1
Cash paid for income taxes (net of refunds)	51.0	51.7	54.3
Brazil [Member]
Income Tax Paid, Foreign, after Refund Received [Abstract]
Foreign	2.9	2.9
Canada [Member]
Income Tax Paid, Foreign, after Refund Received [Abstract]
Foreign		3.7
Germany [Member]
Income Tax Paid, Foreign, after Refund Received [Abstract]
Foreign	3.3	4.2	7.4
Italy [Member]
Income Tax Paid, Foreign, after Refund Received [Abstract]
Foreign	3.9	3.9
U.K. [Member]
Income Tax Paid, Foreign, after Refund Received [Abstract]
Foreign	6.8	6.7	8.6
Other Foreign [Member]
Income Tax Paid, Foreign, after Refund Received [Abstract]
Foreign	$ 4.9	$ 1.4	$ 6.1

Fair Value Measurements

12 Months Ended

Dec. 31, 2025

Fair Value Disclosures [Abstract]

Fair Value Measurements

Note 14. Fair Value Measurements

Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). The Company utilizes a mid-market pricing convention for valuing the majority of its assets and liabilities measured and reported at fair value. The Company utilizes market data or assumptions that market participants would use in pricing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation

technique. These inputs can be readily observable, market corroborated or generally unobservable. The Company primarily applies the market approach for recurring fair value measurements and endeavors to utilize the best available information. Accordingly, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. The Company is able to classify fair value balances based on the observability of those inputs. The Company gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurement) and the lowest priority to unobservable inputs (Level 3 measurement). Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy Levels.

In 2025, the Company evaluated the fair value hierarchy levels assigned to its assets and liabilities, and concluded that there should be no transfers into or out of Levels 1, 2 and 3.

The following table presents the carrying amount and fair values of the Company’s assets and liabilities measured on a recurring basis:


	December 31, 2025				December 31, 2024
(in millions)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Assets
Derivatives (Level 1 measurement):
Other current and non-current assets:
Emissions Trading Scheme credits	$	3.2	$	3.2	$	3.9	$	3.9
Foreign currency forward exchange contracts		3.4		3.4		1.5		1.5
Liabilities
Derivatives (Level 1 measurement):
Non-financial liabilities (Level 3 measurement):
Acquisition-related contingent consideration		8.3		8.3		20.1		20.1

The following methods and assumptions were used to estimate the fair values:

Emissions Trading Scheme credits: The fair value is determined by the open market pricing at the end of the reporting period.

Derivatives: The fair value of derivatives relating to foreign currency forward exchange contracts and interest rate swaps are derived from current settlement prices and comparable contracts using current assumptions. Foreign currency forward exchange contracts primarily relate to contracts entered into to hedge future known transactions or hedge balance sheet net cash positions. The movements in the carrying amounts and fair values of these contracts are largely due to changes in exchange rates against the U.S. dollar.

Acquisition-related contingent consideration: Contingent consideration payable in cash is discounted to its fair value at each balance sheet date. Where contingent consideration is dependent upon pre-determined financial targets, an estimate of the fair value of the likely consideration payable is made at each balance sheet date. The contingent consideration payable at December 31, 2025 has been calculated

based on the latest forecast. The movement in the current year relates to an $18.5 million reduction in the fair value of the expected payable relating to the acquisition of QGP, partially offset by an accretion charge of $2.6 million, the impact of foreign exchange of $2.8 million and a $1.3 million increase relating to the acquisition of the trade and net assets of Biotechnology Solutions LLC which has not been discounted to its fair value on the basis of materiality (see Note 8 of the Notes to the Consolidated Financial Statements for additional information).

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Cash Flows from Operating Activities
Net income	$ 116.6	$ 35.6	$ 139.1
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	43.6	43.5	39.3
Adjustment to fair value of contingent consideration	(15.9)	3.4	0.0
Impairment of property, plant and equipment	22.9	0.0	0.0
Impairment of intangible assets	19.1	0.0	0.0
Deferred taxes	(10.2)	(39.3)	3.6
Profit on disposal of property, plant and equipment	(0.2)	(0.2)	0.0
Non-cash movements of defined benefit pension plans	2.7	151.9	(3.3)
Stock option compensation	8.1	8.5	8.0
Changes in assets and liabilities, net of effects of acquired and divested companies:
Trade and other accounts receivable	21.6	4.3	(12.6)
Inventories	(6.6)	(11.8)	83.0
Prepaid expenses	1.8	(2.8)	(4.2)
Accounts payable and accrued liabilities	(32.8)	(4.5)	(26.9)
Plant closure provisions	(1.9)	0.9	4.0
Accrued income taxes	(21.8)	6.3	(25.9)
Unrecognized tax benefits	0.0	(14.8)	1.4
Other assets and liabilities	(8.7)	3.5	1.8
Net cash provided by operating activities	138.3	184.5	207.3
Cash Flows from Investing Activities
Capital expenditures	(50.3)	(41.4)	(62.1)
Proceeds on disposal of property, plant and equipment	1.1	0.5	0.1
Business combinations, net of cash acquired	(0.7)	(0.2)	(34.7)
Internally developed software	(25.2)	(20.9)	(15.1)
Net cash used in investing activities	(75.1)	(62.0)	(111.8)
Cash Flows from Financing Activities
Non-controlling interest	1.9	2.4	0.0
Repayment of term loan	0.0	0.0	(2.3)
Refinancing costs	0.0	(0.3)	(1.4)
Dividend paid	(42.4)	(38.8)	(35.1)
Issue of treasury stock	0.5	2.1	0.9
Repurchase of common stock	(23.9)	(0.7)	(1.1)
Net cash used in financing activities	(63.9)	(35.3)	(39.0)
Effect of foreign currency exchange rate changes on cash	4.0	(1.7)	0.1
Net change in cash and cash equivalents	3.3	85.5	56.6
Cash and cash equivalents at beginning of year	289.2	203.7	147.1
Cash and cash equivalents at end of year	$ 292.5	$ 289.2	$ 203.7

Other Intangible Assets - Schedule of Amortization Expense (Detail) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 373.3	$ 331.9	$ 315.1
Accumulated amortization	(305.6)	(266.5)	$ (257.8)
Product Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	34.0	34.0
Accumulated amortization	(34.0)	(34.0)
Brand Names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	8.9	8.9
Accumulated amortization	(8.9)	(8.9)
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	55.1	55.1
Accumulated amortization	(55.1)	(44.6)
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	137.3	130.6
Accumulated amortization	(129.2)	(111.9)
Internally Developed Software [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	113.4	78.7
Accumulated amortization	(53.8)	(42.5)
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	24.6	24.6
Accumulated amortization	$ (24.6)	$ (24.6)

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 20
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-20

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 20
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-20

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 38
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-38

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 38
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-38

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 38
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-38

Reference 8: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 38
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-38

Reference 9: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 38
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-38

Reference 10: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 38
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-38

Reference 11: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 12: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 13: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 14: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 15: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 16: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 17: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 18: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 31
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-31

Reference 19: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 29
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-29

Reference 20: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 29
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-29

Reference 21: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 20
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-20

Reference 22: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 20
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-20

Reference 23: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 14
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-14

Reference 24: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 14
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-14

Reference 25: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-14

Reference 26: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 14
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-14

Reference 27: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479876/805-20-55-14

Reference 28: http://www.xbrl.org/2003/role/exampleRef
-Name Accounting Standards Codification
-Section 55
-Paragraph 40
-SubTopic 30
-Topic 350
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482640/350-30-55-40

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482665/350-30-50-2

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482665/350-30-50-2

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482686/350-30-45-1

Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482665/350-30-50-2

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482665/350-30-50-3

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Topic 985
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481283/985-20-50-2

Reference 35: http://www.xbrl.org/2003/role/disclosureRef
-Topic 926
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483154/926-20-50-5

+ Details

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 116.6	$ 35.6	$ 139.1
Changes in cumulative translation adjustment	53.4	(33.7)	18.3
Amortization of prior service cost	0.0	8.4	0.5
Amortization of actuarial net losses/(gains)	0.0	(0.2)	(2.1)
Actuarial net gains/(losses) arising during the year	0.9	(28.3)	(23.4)
Pension scheme settlement	0.0	138.1	0.0
Other comprehensive income, before tax	170.9	119.9	132.4
Tax related to cumulative translation adjustment	2.0	13.6	(2.4)
Tax related to other movements	0.0	(40.8)	6.2
Total comprehensive income	$ 172.9	$ 92.7	$ 136.2

Other Intangible Assets

12 Months Ended

Dec. 31, 2025

Goodwill and Intangible Assets Disclosure [Abstract]

Other Intangible Assets

Note 9. Other Intangible Assets

The following table analyzes other intangible assets movement for 2025 and 2024.


(in millions)	2025			2024
Gross cost at January 1	$	331.9		$	315.1
Additions		23.6			24.3
Exchange effect		17.8			(7.5	)
Gross cost at December 31		373.3			331.9
Accumulated amortization at January 1		(266.5	)		(257.8	)
Amortization expense		(11.6	)		(12.6	)
Impairment		(19.0	)		—
Exchange effect		(8.5	)		3.9
Accumulated amortization at December 31		(305.6	)		(266.5	)
Net book amount at December 31	$	67.7		$	65.4

Amortization expense

The amortization expense was $11.6 million, $12.6 million and $10.6 million in 2025, 2024 and 2023, respectively. Excluding the impact of foreign exchange translation on the balance sheet, $1.7 million, $2.3 million and $2.3 million of amortization, respectively, was recognized in cost of goods sold, and the remainder was recognized in selling, general and administrative expenses.

In 2025, we capitalized $23.6 million (2024 - $20.8 million) in relation to our internal-use developed software for a new Enterprise Resource Planning (“ERP”) system covering all our regions. The expenses capitalized include the acquisition costs for the software as well as the external consultancy costs and the internal employee costs relating to software development. The additional completion costs are currently expected to be approximately $4.2 million. Our current plan is to complete the implementation of the new ERP system by the middle of 2026. We have determined the useful economic life of the ERP system to be up to 12 years.

In 2024, within the remeasurement period, we finalized the valuation of customer lists in relation to the acquisition of QGP in December 2023. This increased the intangible asset capitalized by $3.5 million in the second quarter of 2024. Management also revised the expected useful life of the customer lists from 10 years to 7 years.

During the quarter ended September 30, 2025, the Company impaired the intangible assets arising from the acquisition of QGP, within its Performance Chemicals segment, and Independence Oilfield Chemicals LLC and Bachman Services LLC., within its Oilfield Services segment. The impaired assets totaled $19.1 million and relate to product technology and customer relationships, which are no longer expected to generate sufficient discounted cash flows to support the valuations due to an expected lack of near-term

recovery in QGP, our oilfield production business in Mexico and our stimulation business in the U.S..

Other intangible assets at December 31, 2025 were:


(in millions)	Gross carrying amount		Accumulated amortization
Product rights	$	34.0	$	(34.0	)
Brand names		8.9		(8.9	)
Technology		55.1		(55.1	)
Customer relationships		137.3		(129.2	)
Internally developed software		113.4		(53.8	)
Other		24.6		(24.6	)
	$	373.3	$	(305.6	)

Other intangible assets at December 31, 2024 were:


(in millions)	Gross carrying amount		Accumulated amortization
Product rights	$	34.0	$	(34.0	)
Brand names		8.9		(8.9	)
Technology		55.1		(44.6	)
Customer relationships		130.6		(111.9	)
Internally developed software		78.7		(42.5	)
Other		24.6		(24.6	)
	$	331.9	$	(266.5	)

Future amortization expense is estimated to be as follows for the next five years:


(in millions)
2026	$	9.9
2027	$	6.5
2028	$	6.2
2029	$	6.2
2030	$	6.2

Fair Value Measurements (Additional Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Acquisition of the trade and net assets	$ 0.7	$ 0.2	$ 34.7
Quimica Geral S A [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Reduction in the fair value of the expected payable	18.5
Accretion charge	2.6
Acquisition related impact of foreign exchange	2.8
Biotechnology Solutions LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Acquisition of the trade and net assets	$ 1.3

Acquisition of QGP Quimica Geral

12 Months Ended

Dec. 31, 2025

Business Combination [Abstract]

Acquisition of QGP Quimica Geral

Note 5. Acquisition of QGP Química Geral

On December 8, 2023, the Company acquired QGP Química Geral (“QGP”). A portion of the consideration is deferred and payable in cash by December 7, 2026, and contingent on the financial performance of QGP for the 12 months ended June 30, 2026.

In the third quarter of 2025, the Company recorded an $18.5 million reduction in the fair value of the expected contingent consideration payable relating to the acquisition of QGP, based on the information available at that time.

The fair value of this deferred, contingent consideration at December 31, 2025 and 2024 was $7.0 million and $20.1 million, respectively. See Note 14 of the Notes to the Consolidated Financial Statements for additional information relating to the fair value calculation.

- Definition

The entire disclosure for business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-8

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 38
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479303/805-10-55-38

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 46
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479303/805-10-55-46

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 43
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479303/805-10-55-43

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 45
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479303/805-10-55-45

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 29
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479303/805-10-55-29

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 29
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479303/805-10-55-29

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-5

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(1)(ii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-3

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-3

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-2

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (f)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-3

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-2

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-4

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-4

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-1

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-1

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-2

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-2

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 40
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479326/805-40-45-1

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/805-30/tableOfContent

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/805-20/tableOfContent

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-7

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-5

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/805-10/tableOfContent

+ Details

Consolidated Statements of Income - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Statement [Abstract]
Net sales	$ 1,778.0	$ 1,845.4	$ 1,948.8
Cost of goods sold	(1,285.6)	(1,302.5)	(1,357.7)
Gross profit	492.4	542.9	591.1
Operating expenses:
Selling, general and administrative	(285.1)	(305.3)	(380.5)
Research and development	(51.0)	(56.5)	(49.0)
Adjustment to fair value of contingent consideration	15.9	(3.4)	0.0
Restructuring charge	(0.9)	0.0	0.0
Impairment of property, plant and equipment	(22.9)	0.0	0.0
Impairment of intangible assets	(19.1)	0.0	0.0
Profit on disposal of property, plant and equipment	0.2	0.2	0.0
Total operating expenses	(362.9)	(365.0)	(429.5)
Operating income	129.5	177.9	161.6
Other income/(expense), net	(0.6)	9.6	10.5
Pension scheme settlement charge	0.0	(155.6)	0.0
Interest income/(expense), net	9.2	9.3	2.3
Income before income tax expense	138.1	41.2	174.4
Income tax expense	(21.5)	(5.6)	(35.3)
Net income	$ 116.6	$ 35.6	$ 139.1
Earnings per share:
Basic	$ 4.69	$ 1.43	$ 5.6
Diluted	$ 4.67	$ 1.42	$ 5.56
Weighted average shares outstanding (in thousands):
Basic	24,880	24,932	24,851
Diluted	24,993	25,119	25,022

Other Intangible Assets - Schedule of Future Amortization Estimated Expense (Detail) $ in Millions	Dec. 31, 2025 USD ($)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2026	$ 9.9
2027	6.5
2028	6.2
2029	6.2
2030	$ 6.2

Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Income tax, Uncertain tax position description	The tax benefits recognized in the financial statements from such positions are then measured based on the largest benefit that has a greater than 50% likelihood of being realized upon settlement.
Research and Development Expense [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Reclassified Operating Expenses	$ 6.9	$ 8.7	$ 7.3

Earnings per Share - Additional Information (Detail) - shares	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Earnings Per Share [Abstract]
Average number of anti-dilutive options excluded from the calculation of diluted earnings per share	23,414	10,413	20,334

Pension and Post-Employment Benefits - Unfunded Defined Benefit Pension Plan (Detail) - German Plan [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Plan net pension charge:
Service cost/(credit)	$ 0.0	$ 0.0	$ 0.1
Interest cost on PBO	0.3	0.3	0.3
Amortization of actuarial net loss/(gain)	0.0	(0.2)	(0.5)
Net periodic cost/(benefit)	$ 0.3	$ 0.1	$ (0.1)
Plan assumptions at December 31, (%):
Discount rate	3.80%	3.20%	3.70%
Inflation rate	2.25%	2.25%	2.25%
Rate of increase in compensation levels	2.75%	2.75%	2.75%

Share-Based Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2025

Assumptions Used to Determine Grant-Date Fair Value of Options

The fair value of each stock option or SEU granted in the year was calculated with the following weighted average assumptions to determine the grant-date fair values of the share-based compensation:


	2025			2024			2023
Dividend yield		1.51	%		1.13	%		1.16	%
Expected life	3 years			3 years			4 years
Volatility		27.0	%		25.5	%		39.7	%
Risk free interest rate		4.16	%		4.38	%		4.47	%

Employee Stock Option

Summary of Transactions of Company's Stock Option Plans

The following tables summarizes the transactions of the Company’s share-based compensation plans for the year ended December 31, 2025.


	Number of shares			Weighted Average Grant-Date Fair Value
Nonvested at December 31, 2024		574,671		$	86.2
Granted		166,337		$	107.1
Vested		(210,227	)	$	77.8
Forfeited		(11,831	)	$	72.5
Cancelled		(87,653	)	$	31.3
Nonvested at December 31, 2025		431,297		$	109.5


	Number of shares			Weighted Average Exercise price		Weighted-Average Remaining Contractual Term (years)
Outstanding at December 31, 2024		619,705		$	23.5
Granted		166,337		$	—
Exercised		(139,904	)	$	3.5
Forfeited		(17,281	)	$	34.0
Cancelled		(87,653	)	$	75.7
Outstanding at December 31, 2025		541,204		$	12.7		2.1
Exercisable at December 31, 2025		109,907		$	49.1		2.7

Accounting Policies

12 Months Ended

Dec. 31, 2025

Accounting Policies [Abstract]

Accounting Policies

Note 2. Accounting Policies

when we can reasonably estimate the amount of the rebate. The estimates are based on our best judgment at the time of sale, which includes anticipated as well as historical performance.

Research and development expenses: Research, development and testing costs are expensed to the income statement as incurred.

Cash equivalents: Investment securities with maturities of three months or less when purchased are considered to be cash equivalents.


Buildings		7 to 25 years
Equipment		3 to 10 years

The estimated useful lives of the major classes of assets are as follows:


Technology		10 to 17 years
Customer lists		7 to 15 years
Brand names		5 to 10 years
Product rights		9 to 10 years
Internally developed software		3 to 12 years
Marketing related		11 years

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Dec. 31, 2025
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Pension and Post-Employment Benefits - Reconciliation of Fair Value of Plan Assets Measured Using Significant Unobservable Inputs (Detail) - United Kingdom Plan [Member] - Significant Unobservable Inputs (Level 3) [Member] - Other Assets [Member] $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 438.7
Realized/unrealized gains/(losses):
Relating to assets still held at the reporting date	(2.2)
Purchases, issuances and settlements	(438.8)
Exchange effect	2.3
Ending balance	$ 0.0

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References + Details

Income Taxes

12 Months Ended

Dec. 31, 2025

Income Tax Disclosure [Abstract]

Income Taxes

Note 11. Income Taxes

The sources of income before income taxes were as follows:


(in millions)	2025		2024			2023
Domestic	$	25.9	$	90.2		$	95.2
Foreign		112.2		(49.0	)		79.2
	$	138.1	$	41.2		$	174.4

The components of income tax expense are summarized as follows:


(in millions)	2025			2024			2023
Current:
Federal	$	4.5		$	16.9		$	12.4
State and local		1.7			2.9			0.2
Foreign		24.3			26.2			18.6
		30.5			46.0			31.2
Deferred:
Federal		(7.7	)		(4.1	)		5.2
State and local		(0.3	)		(0.5	)		0.3
Foreign		(1.0	)		(35.8	)		(1.4	)
		(9.0	)		(40.4	)		4.1
Total:
Federal		(3.2	)		12.8			17.6
State and local		1.4			2.4			0.5
Foreign		23.3			(9.6	)		17.2
	$	21.5		$	5.6		$	35.3

The effective tax rate varies from the U.S. federal statutory rate because of the factors indicated below. In considering the items that create variances when compared to the U.S. federal statutory rate, it is worth noting that the percentage impact of a given item in the table below would be higher in 2024 because income before income taxes in 2024 is significantly lower than in 2025 and 2023.


(in millions)	2025						2024						2023
	in Dollars			in Percent			in Dollars			in Percent			in Dollars			in Percent
U.S. federal statutory tax rate	$	29.0			21.0	%	$	8.7			21.0	%	$	36.6			21.0	%
State and local income taxes, net of federal income tax effect*		1.7			1.2	%		2.7			6.6	%		1.0			0.6	%
Foreign tax effects:
Brazil:
Changes in valuation allowance	**			**				2.7			6.6	%	**			**
Adjustment to contingent consideration		(3.2	)		-2.3	%		0.7			1.7	%	**			**
Foreign tax rate differential	**			**			**			**				(1.8	)		-1.0	%
Other		(1.2	)		-0.8	%		0.8			1.9	%		0.3			0.2	%
Germany:
Foreign tax rate differential	**			**				0.7			1.7	%	**			**
Other	**			**				(0.1	)		-0.2	%	**			**
Italy	**			**				0.6			1.5	%	**			**
U.K.:
Foreign tax rate differential		2.1			1.5	%		(3.4	)		-8.3	%		1.3			0.7	%
Foreign currency transactions	**			**			**			**				(2.6	)		-1.5	%
Innovation incentives		(3.2	)		-2.3	%		(3.2	)		-7.8	%		(1.5	)		-0.9	%
Other		0.4			0.3	%		0.4			1.0	%		0.5			0.3	%
Other foreign jurisdictions		2.7			2.0	%		0.2			0.5	%		1.7			1.0	%
Effect of cross-border tax laws:
Global intangible low-taxed income, net of foreign tax credit		0.8			0.6	%		4.3			10.4	%		(0.2	)		-0.1	%
Subpart F income, net of foreign tax credit		—			0.0	%		1.2			2.9	%		0.2			0.1	%
Incentive for foreign derived intangible income		(0.5	)		-0.4	%		(1.9	)		-4.6	%		(4.5	)		-2.6	%
Tax on unremitted foreign earnings		2.1			1.5	%		0.8			1.9	%		2.4			1.4	%
Other		0.1			0.1	%		0.3			0.7	%		—			0.0	%
Tax credits		(0.5	)		-0.4	%		(0.9	)		-2.2	%		(1.0	)		-0.6	%
Nontaxable or nondeductible items:
Nondeductible officer compensation	**			**				2.0			4.9	%		1.8			1.0	%
Other		0.7			0.5	%		(0.9	)		-2.1	%		(0.2	)		-0.1	%
Changes in unrecognized tax benefits		—			0.0	%		(10.1	)		-24.5	%		1.3			0.7	%
Tax impact of internal reorganizations		(9.5	)		-6.9	%		—			0.0	%		—			0.0	%
	$	21.5			15.6	%	$	5.6			13.6	%	$	35.3			20.2	%

* State taxes in Texas, Louisiana and Oklahoma made up the majority (greater than 50%) of the tax effect in this category in 2025 (2024 and 2023: Texas, California and Oklahoma).

** The amount of income tax during the year does not meet the required threshold and is included in relevant 'Other' category.

The effective tax rate has been positively impacted in 2025 by the tax impact of internal reorganizations. This item arose due to the allocation of a partnership basis difference which was recognized in 2025, following the finalization of our estimate of the tax impact of the dissolution of the partnership on December 31, 2024. While the change in estimate had no impact on pre-tax income, it has resulted in the recognition of a deferred tax asset of $9.5 million and a credit to net income of $9.5 million for the twelve months ended December 31, 2025.

In addition, the effective tax rate has been positively impacted in 2025 by an adjustment of $15.9 million to the fair value of contingent consideration associated with the acquisition of QGP in Brazil. This adjustment has no impact on the Company’s current or future tax liabilities and therefore impacts on the effective tax rate.

The Company benefits from innovation reliefs in relation to relevant research and development expenditure in certain jurisdictions, notably the U.K. and the U.S., which have a positive impact on the effective tax rate.

The level of foreign-derived intangible income benefit that the Company is entitled to has had a positive impact on the effective tax rate in 2025 and the disclosed prior years, although the benefit has declined in 2025 due to a decrease in U.S. export sales.

The Company is subject to state taxes and local taxes primarily in the U.S. in addition to federal taxes. The effective tax rate in 2025 and the disclosed prior years has been negatively impacted by these taxes.

Cash paid for income taxes (net of refunds) consisted of the following:


(in millions)	2025		2024		2023
Federal	$	26.1	$	27.5	$	27.5
State and local		3.1		1.4		4.7
Foreign:
Brazil		2.9		2.9	*
Canada	*			3.7	*
Germany		3.3		4.2		7.4
Italy		3.9		3.9	*
U.K.		6.8		6.7		8.6
Other Foreign		4.9		1.4		6.1
		21.8		22.8		22.1
	$	51.0	$	51.7	$	54.3

*The amount of income taxes paid during the year does not meet the required threshold and is included in 'Other Foreign'.

Details of deferred tax assets and liabilities are analyzed as follows:


(in millions)	2025			2024
Deferred tax assets:
Stock compensation	$	3.3		$	3.7
Net operating loss carry forwards		8.2			8.8
Other intangible assets		15.6			4.8
Accretion expense		3.2			3.2
Restructuring provision		1.4			1.5
Employee related liabilities		4.6			9.2
Foreign tax credits		3.0			2.1
Operating lease liabilities		12.9			11.1
Inventory provisions		9.4			9.0
Pensions		1.2			0.5
Carried forward interest deductions		2.7			1.4
Bad debt reserves		1.1			1.4
Research and experimental expenditure		6.1			8.3
Other		5.7			3.4
Subtotal		78.4			68.4
Less valuation allowance		(2.8	)		(2.4	)
Total net deferred tax assets	$	75.6		$	66.0
Deferred tax liabilities:
Property, plant and equipment	$	(27.0	)	$	(29.5	)
Intangible assets including goodwill		(31.2	)		(31.6	)
Customer relationships		(1.0	)		(1.7	)
Unremitted overseas earnings		(7.2	)		(5.1	)
Right-of-use assets		(12.9	)		(10.7	)
Other		(1.8	)		(1.5	)
Total deferred tax liabilities	$	(81.1	)	$	(80.1	)
Net deferred tax liability	$	(5.5	)	$	(14.1	)
Deferred tax assets	$	13.6		$	9.4
Deferred tax liabilities		(19.1	)		(23.5	)
	$	(5.5	)	$	(14.1	)

The Company assesses the available positive and negative evidence to estimate whether sufficient future taxable income will be generated to permit use of the existing deferred tax assets. Available evidence considered in determining the use of deferred tax assets includes, but is not limited to, cumulative losses arising in recent accounting periods, the Company’s estimate of future taxable income and any applicable tax-planning strategies. Based on such evidence, if it is more likely than not that some portion or all of such deferred tax assets will not be realized, a valuation allowance is recorded to reduce the Company’s deferred tax assets. On the basis of this evaluation, as of December 31, 2025, a valuation allowance of $2.8 million has been recorded to recognize only the portion of the deferred tax asset that is more likely than not to be realized. The amount of the deferred tax asset considered realizable, however, could be

adjusted if estimates of future taxable income during the carry forward period are reduced or increased or if other evidence becomes available.

As of December 31, 2025, the Company has approximately $6.8 million of tax-effected foreign net operating loss carryforwards, net of valuation allowance, across three of the Company’s foreign subsidiaries, which can be carried forward indefinitely.

A roll-forward of unrecognized tax benefits and associated accrued interest and penalties is as follows:


(in millions)	Unrecognized Tax Benefits			Interest and Penalties			Total
Opening balance at January 1, 2023	$	10.2		$	3.2		$	13.4
Reductions for tax positions of prior periods		—			—			—
Additions for tax positions of prior periods		0.3			1.1			1.4
Closing balance at December 31, 2023		10.5			4.3			14.8
Current		(1.0	)		(0.2	)		(1.2	)
Non-current	$	9.5		$	4.1		$	13.6
Opening balance at January 1, 2024	$	10.5		$	4.3		$	14.8
Reductions for tax positions of prior periods		(10.5	)		(5.1	)		(15.6	)
Additions for tax positions of prior periods		—			0.8			0.8
Closing balance at December 31, 2024		—			—			—
Current		—			—			—
Non-current	$	—		$	—		$	—
Opening balance at January 1, 2025	$	—		$	—		$	—
Reductions for tax positions of prior periods		—						—
Additions for tax positions of prior periods		—						—
Closing balance at December 31, 2025		—			—			—
Current		—			—			—
Non-current	$	—		$	—		$	—

As at December 31, 2025, the Company has no unrecognized tax benefits.

- Definition

The entire disclosure for income tax.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 740
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477617/942-740-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 740
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478822/944-740-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 231
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-231

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12C
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12C

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12B

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 270
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477891/740-270-50-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 6.I.5.Q1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479360/740-10-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480990/946-20-50-13

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/740/tableOfContent

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-14

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-21

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-17

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479360/740-10-S99-2

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482603/740-30-50-2

+ Details

Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2025

Fair Value Disclosures [Abstract]

Carrying Amount and Fair Values of the Company's Assets and Liabilities Measured on a Recurring Basis

The following table presents the carrying amount and fair values of the Company’s assets and liabilities measured on a recurring basis:


	December 31, 2025				December 31, 2024
(in millions)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Assets
Derivatives (Level 1 measurement):
Other current and non-current assets:
Emissions Trading Scheme credits	$	3.2	$	3.2	$	3.9	$	3.9
Foreign currency forward exchange contracts		3.4		3.4		1.5		1.5
Liabilities
Derivatives (Level 1 measurement):
Non-financial liabilities (Level 3 measurement):
Acquisition-related contingent consideration		8.3		8.3		20.1		20.1

Reclassifications out of Accumulated Other Comprehensive Loss (Tables)

12 Months Ended

Dec. 31, 2025

Equity [Abstract]

Summary of Reclassifications Out of Accumulated Other Comprehensive Loss

Reclassifications out of accumulated other comprehensive loss (“AOCL”) for 2025 were:


(in millions)
Details about AOCL Components	Amount Reclassified from AOCL		Affected Line Item in the Statement where Net Income is Presented
Defined benefit pension plan items:
Amortization of prior service cost	$	—	See (1) below
Amortization of actuarial net losses		—	See (1) below
		—	Total before tax
		—	Income tax expense
Total reclassifications	$	—	Net of tax

These items are included in the computation of net periodic pension cost. See Note 10 of the Notes to the Consolidated Financial Statements for additional information.

Reclassifications out of AOCL for 2024 were:


(in millions)
Details about AOCL Components	Amount Reclassified from AOCL			Affected Line Item in the Statement where Net Income is Presented
Defined benefit pension plan items:
Amortization of prior service cost	$	8.4		See (1) below
Amortization of actuarial net losses		(0.2	)	See (1) below
Pension scheme settlement		138.1		See (1) below
		146.3		Total before tax
		(47.8	)	Income tax expense
Total reclassifications	$	98.5		Net of tax

These items are included in the computation of net periodic pension cost. See Note 10 of the Notes to the Consolidated Financial Statements for additional information.

Changes in Accumulated Other Comprehensive Loss

Changes in AOCL for 2025, net of tax, were:


(in millions)	Defined Benefit Pension Plan Items		Cumulative Translation Adjustments			Total
Balance at December 31, 2024	$	—	$	(91.0	)	$	(91.0	)
Other comprehensive income/(losses) before reclassifications		—		55.4			55.4
Amounts reclassified from AOCL		—		—			—
Actuarial net losses arising during the year		0.9		—			0.9
Net current period other comprehensive income/(losses)		0.9		55.4			56.3
Balance at December 31, 2025	$	0.9	$	(35.6	)	$	(34.7	)

Changes in AOCL for 2024, net of tax, were:


(in millions)	Defined Benefit Pension Plan Items			Cumulative Translation Adjustments			Total
Balance at December 31, 2023	$	(77.2	)	$	(70.9	)	$	(148.1	)
Other comprehensive income/(losses) before reclassifications		—			(20.1	)		(20.1	)
Amounts reclassified from AOCL		98.5			—			98.5
Actuarial net losses arising during the year		(21.3	)		—			(21.3	)
Net current period other comprehensive income/(losses)		77.2			(20.1	)		57.1
Balance at December 31, 2024	$	—		$	(91.0	)	$	(91.0	)

Pension and Post-Employment Benefits - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Pension scheme settlement charge		$ 0.0	$ 155.6	$ 0.0
Pension asset		0.0	2.4
Annual cash contribution			0.0
Income tax expense		(21.5)	(5.6)	(35.3)
Amount of unrecognized actuarial net losses, net of tax		0.9	(21.3)	(17.5)
Other Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Amount of contributions to defined contribution schemes		15.3	13.9
United Kingdom Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension asset		0.0	2.5	$ 459.2
Asset		0.0	2.4
Funds to cover pension related costs	$ 8.4	(0.9)	(8.4)
Income tax expense			$ (2.1)
Percentage of asset allocation, actual			100.00%	100.00%
United Kingdom Plan [Member] \| Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected Benefit Obligation		0.0	$ 0.1	$ 424.1
Europe [Member] \| Performance Chemicals [Member]
Defined Benefit Plan Disclosure [Line Items]
Post-employment obligations European businesses		3.8	4.1
France [Member]
Defined Benefit Plan Disclosure [Line Items]
Amount of unrecognized actuarial net losses, net of tax		$ 0.1	$ 0.2

Stockholders' Equity - Stockholder's Equity (Detail) - shares	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Equity [Abstract]
Common Stock, Beginning balance	29,554,500	29,554,500	29,554,500
Common Stock, Ending balance	29,554,500	29,554,500	29,554,500
Treasury Stock, Beginning balance	4,594,943	4,687,000	4,789,000
Exercise of options, Treasury Stock	(82,000)	(97,000)	(113,000)
Stock purchases, Treasury Stock	264,000	5,000	11,000
Treasury Stock, ending balance	4,776,918	4,594,943	4,687,000

Consolidated Statements of Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Non-Controlling Interest [Member]
Beginning Balance at Dec. 31, 2022	$ 1,040.4	$ 0.3	$ 354.1	$ (95.4)	$ 924.2	$ (145.2)	$ 2.4
Net income	139.1				139.1
Dividend paid	(35.1)				(35.1)
Changes in cumulative translation adjustment, net of tax	15.9					15.9
Share of net income	0.1						0.1
Treasury stock re-issued	1.1		(1.1)	2.2
Treasury stock repurchased	(1.1)			(1.1)
Stock option compensation	8.0		8.0
Amortization of prior service cost, net of tax	0.4					0.4
Amortization of actuarial net gains, net of tax	(1.7)					(1.7)
Actuarial net losses arising during the year, net of tax	(17.5)					(17.5)
Ending Balance at Dec. 31, 2023	1,149.6	0.3	361.0	(94.3)	1,028.2	(148.1)	2.5
Net income	35.6				35.6
Dividend paid	(38.8)				(38.8)
Changes in cumulative translation adjustment, net of tax	(20.1)					(20.1)
Share of net income	2.4						2.4
Treasury stock re-issued	2.4		0.4	2.0
Treasury stock repurchased	(0.7)			(0.7)
Stock option compensation	8.5		8.5
Amortization of prior service cost, net of tax	6.3					6.3
Amortization of actuarial net gains, net of tax	(0.2)					(0.2)
Actuarial net losses arising during the year, net of tax	(21.3)					(21.3)
Pension scheme settlement	92.4					92.4
Ending Balance at Dec. 31, 2024	1,216.1	0.3	369.9	(93.0)	1,025.0	(91.0)	4.9
Net income	116.6				116.6
Dividend paid	(42.4)				(42.4)
Changes in cumulative translation adjustment, net of tax	55.4					55.4
Share of net income							1.9
Treasury stock re-issued	0.2		(1.5)	1.7
Treasury stock repurchased	(23.9)			(23.9)
Stock option compensation	8.1		8.1
Actuarial net losses arising during the year, net of tax	0.9					0.9
Ending Balance at Dec. 31, 2025	$ 1,332.9	$ 0.3	$ 376.5	$ (115.2)	$ 1,099.2	$ (34.7)	$ 6.8

Reclassifications out of Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 1,211.2
Other comprehensive income/(losses) before reclassifications	55.4	$ (20.1)
Amounts reclassified from AOCL	0.0	98.5
Actuarial net losses arising during the year	0.9	(21.3)	$ (17.5)
Net current period other comprehensive income/(losses)	56.3	57.1
Ending Balance	1,326.1	1,211.2
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(91.0)	(148.1)
Actuarial net losses arising during the year	0.9	(21.3)	(17.5)
Ending Balance	(34.7)	(91.0)	(148.1)
Defined Benefit Pension Plan Items [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	0.0	(77.2)
Other comprehensive income/(losses) before reclassifications	0.0	0.0
Amounts reclassified from AOCL	0.0	98.5
Actuarial net losses arising during the year	0.9	(21.3)
Net current period other comprehensive income/(losses)	0.9	77.2
Ending Balance	0.9	0.0	(77.2)
Foreign Currency Translation Items [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(91.0)	(70.9)
Other comprehensive income/(losses) before reclassifications	55.4	(20.1)
Amounts reclassified from AOCL	0.0	0.0
Actuarial net losses arising during the year	0.0	0.0
Net current period other comprehensive income/(losses)	55.4	(20.1)
Ending Balance	$ (35.6)	$ (91.0)	$ (70.9)

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480870/815-30-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480870/815-30-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480870/815-30-50-2

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480870/815-30-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-4

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-5

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-17

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 20
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-20

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 20
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-20

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 20
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-20

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 20
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-20

+ Details

- Definition

Amount after tax, before reclassification adjustments of other comprehensive income (loss).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-14A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480870/815-30-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-5

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-17

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 20
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-20

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(19))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-4

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-SubTopic 10
-Topic 220
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482739/220-10-55-15

+ Details

- Definition

Amount after tax and reclassification adjustments of other comprehensive income (loss).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-SubTopic 10
-Topic 505
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-6

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-17

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(19))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-4

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-5

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 20
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-20

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(21))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(23))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1B
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-1B

Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-SubTopic 10
-Topic 220
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482739/220-10-55-15

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1A
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-1A

+ Details

- Definition

Amount after tax of reclassification adjustments of other comprehensive income (loss).

+ References

+ Details

- Definition

Amount of equity (deficit) attributable to parent. Excludes temporary equity and equity attributable to noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(i))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(30))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(31))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 852
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481372/852-10-55-10

Reference 8: http://www.xbrl.org/2003/role/exampleRef
-Topic 946
-SubTopic 830
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479168/946-830-55-12

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04(19))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.6-05(4))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479170/946-210-S99-2

Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(4)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(6))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(7))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3

Reference 14: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 15: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481687/323-10-50-3

Reference 16: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 4.E)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480418/310-10-S99-2

+ Details

Related Party Transactions

12 Months Ended

Dec. 31, 2025

Related Party Transactions

Note 21. Related Party Transactions

Mr. Patrick S. Williams has been an executive director of the Company since April 2009 and has been a non-executive director of AdvanSix, a chemicals manufacturer, since February 2020. In 2025, the Company did not purchase any product from AdvanSix (2024 – nil; 2023 - $0.4 million). As at December 31, 2025, the Company owed nil to AdvanSix (December 31, 2024 – nil).

Mr. Robert I. Paller was a non-executive director of the Company since November 1, 2009 until May 10, 2024, when he did not stand for re-election to the board. The Company has retained and continues to retain Smith, Gambrell & Russell, LLP (“SGR”), a law firm with which Mr. Paller holds a position. From January 1, 2024 until May 10, 2024 the Company incurred fees from SGR of $0.2 million (2023 – $0.3 million). As at December 31, 2024, the Company owed nil to SGR.

Mr. David F. Landless has been a non-executive director of the Company since January 1, 2016 and is a non-executive director of Ausurus Group Limited which owns European Metal Recycling Limited (“EMR”). The Company has sold scrap metal to EMR in 2025 for a value of less than $0.1 million (2024 - less than $0.1 million; 2023 – $0.1 million). A tendering process is operated periodically to select the best buyer for the sale of scrap metal by the Company. As at December 31, 2025, EMR owed nil for scrap metal purchased from the Company (December 31, 2024 – nil).

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483326/850-10-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480990/946-20-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480990/946-20-50-5

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480990/946-20-50-6

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477968/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477968/946-235-50-2

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(g)(3))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(c))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(e))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/850/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483326/850-10-50-6

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483326/850-10-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483326/850-10-50-1

+ Details

Leases - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Leases [Line Items]
Additional leases that have not yet commenced	$ 0.7	$ 0.3
Maximum [Member]
Leases [Line Items]
Operating and finance leases, remaining lease terms	20 years
Minimum [Member]
Leases [Line Items]
Operating and finance leases, remaining lease terms	1 year

Acquisition of QGP Quimica Geral - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2025	Dec. 31, 2025	Dec. 31, 2024
Business Acquisition [Line Items]
Acquisition-related contingent deferred consideration		$ 1.3	$ 20.1
QGP Quimica Geral [Member]
Business Acquisition [Line Items]
Acquisition-related contingent deferred consideration		$ 7.0	$ 20.1
Reduction in the fair value of the expected payable	$ 18.5

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-4

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-8

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 47
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479303/805-10-55-47

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-5

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (f)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(1)(ii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-2

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-2

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-2

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (f)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-1

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-3

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4A
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-4A

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-4

Reference 22: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-1

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-1

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-1

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4A
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-4A

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-1

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-1

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-4A

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-4

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (e)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-1

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-1

Reference 35: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-1

Reference 36: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-1

Reference 37: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-2

Reference 38: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (g)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-2

Reference 39: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (g)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-2

Reference 40: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (g)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-2

Reference 41: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (g)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-2

Reference 42: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-2

+ Details

Pension and Post-Employment Benefits

12 Months Ended

Dec. 31, 2025

Retirement Benefits [Abstract]

Pension and Post-Employment Benefits

Note 10. Pension and Post-Employment Benefits

United Kingdom plan

The Company previously maintained a defined benefit pension plan covering certain current and former employees in the United Kingdom (the “UK Plan”).

In 2024, the Company completed a buy-out of the UK Plan. The buy-out meant that the Company was no longer responsible for the future obligation for retirement benefits payable to current and former employees. As a consequence, the Company recognized a one-off, non-cash settlement charge of $155.6 million in the income statement relating to the updated valuations at the time of the buy-out and the recycling of historical pension costs previously held in the statement of comprehensive income.

As of December 31, 2024, the remaining asset on the balance sheet was $2.5 million, relating to cash held to cover the remaining expenses of the scheme, being partly offset by the remaining Projected Benefit Obligation ("PBO") of $0.1 million, reflecting the UK Plan’s residual liabilities in respect of Guaranteed Minimum Pension equalization top-up payments due to former members of the UK Plan.

On July 29, 2025, the UK Plan was fully wound up. As of December 31, 2025, there were no remaining assets on the balance sheet (December 31, 2024 $2.4 million).

Following the UK Plan buy-out, the Company is no longer required to make future cash contributions to the UK Plan. In 2024, the Company contributed $0.0 million in cash to the UK Plan in accordance with an agreement with the trustees.

In September 2024, the Company received $8.4 million from the UK Plan as recovery of pension related costs previously incurred, which has been credited against the service cost in 2024, resulting in an associated income tax expense of $2.1 million.


(in millions)	2025		2024			2023
Service cost/(credit)	$	1.5	$	(4.9	)	$	3.4
Interest cost on PBO		—		18.6			19.6
Expected return on plan assets		—		(25.9	)		(25.2	)
Amortization of prior service cost		—		16.8			0.5
Amortization of actuarial net losses		—		—			(1.6	)
Recycling of residual reserves		—		138.8			—
Net periodic cost/(benefit)	$	1.5	$	143.4		$	(3.3	)

The income statement captions are shown here:


Selling, general and administrative	2025		2024			2023
Service cost/(credit)	$	1.5	$	(4.9	)	$	3.4

Other expense/(income), net	2025		2024			2023
Interest cost on PBO	$	—		18.6			19.6
Expected return on plan assets		—		(25.9	)		(25.2	)
Amortization of prior service cost		—		—			0.5
Amortization of actuarial net losses		—		—			(1.6	)
	$	—	$	(7.3	)	$	(6.7	)

Pension scheme settlement charge	2025		2024			2023
Amortization of prior service cost	$	—		16.8			—
Recycling of residual reserves		—		138.8			—
		—		155.6			—
Tax relating to the amortization of prior service cost		—		(4.2	)		—
Tax relating to the recycling of residual reserves		—		(34.7	)		—
	$	—	$	116.7		$	—

The other financial statement captions relating to the buy-out settlement are shown here:


Recognized in Other Comprehensive Income	2025		2024			2023
Recycling of residual reserves	$	—		138.8			—
Release of historic cumulative translation adjustments		—		(0.7	)		—
		—		138.1			—
Tax relating to the recycling of residual reserves		—		(34.7	)		—
Tax relating to historic cumulative translation adjustments		—		(11.0	)		—
	$	—	$	92.4		$	—

Recognized in Reclassifications out of Accumulated Other Comprehensive Loss	2025		2024			2023
Recycling of residual reserves	$	—		138.8			—
Release of historic cumulative translation adjustments		—		(0.7	)		—
		—		138.1			—
Tax relating to the recycling of residual reserves		—		(34.7	)		—
Tax relating to historic cumulative translation adjustments		—		(11.0	)		—
	$	—	$	92.4		$	—


Plan assumptions at December 31, (%):	2025	2024		2023
Discount rate	n/a		5.18		4.59
Inflation rate	n/a		2.85		2.70
Rate of return on plan assets – overall on bid-value	n/a		4.20		4.25


Plan asset allocation by category (%):	2025	2024		2023
Debt securities and insurance contracts	n/a		—		96
Cash	n/a		100		4
	n/a		100		100

Following the buy-out, the UK Plan does not need to follow an investment strategy.

Movements in PBO and fair value of UK Plan assets are as follows:


(in millions)	2025			2024
Change in PBO:
Opening balance	$	0.1		$	424.1
Interest cost		—			18.6
Service cost/(credit)		1.5			(4.9	)
Benefits paid		—			(32.9	)
Plan amendments		—			8.4
Scheme closure expenses		(1.6	)		—
Actuarial losses/(gains)		—			3.7
Settlements		—			(419.2	)
Exchange effect		—			2.3
Closing balance	$	—		$	0.1
Fair value of plan assets:
Opening balance	$	2.5		$	459.2
Return of funds to cover historic expenses		(0.9	)		(8.4	)
Scheme closure expenses		(1.6	)		—
Benefits paid		—			(32.9	)
Actual return on assets		—			1.5
Settlements		—			(419.2	)
Exchange effect		—			2.3
Closing balance	$	—		$	2.5
Net pension asset	$	—		$	2.4

The fair values of pension assets by level of input were as follows:


(in millions)	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
At December 31, 2024
Cash		2.5						2.5
Total plan assets	$	2.5	$	—	$	—	$	2.5

The reconciliation of the fair value of the UK Plan assets measured using significant unobservable inputs was as follows:


(in millions)	Other Assets
Balance at December 31, 2023	$	438.7
Realized/unrealized gains/(losses):
Relating to assets still held at the reporting date		(2.2	)
Purchases, issuances and settlements		(438.8	)
Exchange effect		2.3
Balance at December 31, 2024	$	—

German plan

The Company also maintains an unfunded defined benefit pension plan covering certain current and former employees in Germany (the “German plan”), which is reported within our Fuel Specialties segment. The German plan is closed to new entrants and has no assets.

The service cost shown in the table below has been recognized in selling, general and administrative expenses within Corporate costs and the other items recognized within other income, net.


(in millions)	2025		2024			2023
Service cost	$	—	$	—		$	0.1
Interest cost on PBO		0.3		0.3			0.3
Amortization of actuarial net loss/(gain)		—		(0.2	)		(0.5	)
Net periodic cost/(benefit)	$	0.3	$	0.1		$	(0.1	)

Plan assumptions at December 31, (%):


Discount rate	3.80	3.20	3.70
Inflation rate	2.25	2.25	2.25
Rate of increase in compensation levels	2.75	2.75	2.75

Movements in PBO of the German plan are as follows:


(in millions)	2025			2024
Change in PBO:
Opening balance	$	9.0		$	9.1
Service cost		—			—
Interest cost		0.3			0.3
Benefits paid		(0.5	)		(0.4	)
Actuarial losses/(gains)		(0.6	)		0.5
Exchange effect		1.2			(0.5	)
Closing balance	$	9.4		$	9.0

Other plans

As at December 31, 2025, we have post-employment obligations in our Performance Chemicals European businesses with a liability of $3.8 million (December 31, 2024 – $4.1 million). For the year ended

December 31, 2025, we have recognized an actuarial gain of $0.1 million in other comprehensive loss in relation to the Performance Chemicals pension in France (December 31, 2024 – $0.2 million).

Company contributions to defined contribution schemes during 2025 were $15.3 million (2024 – $13.9 million), across all of our reporting segments.

- Definition

The entire disclosure for retirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (o)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (p)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (q)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 60
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480266/715-60-50-3

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480126/715-20-S99-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 70
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480794/715-70-50-1

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480482/715-20-55-17

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(iv)(03)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (l)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/715/tableOfContent

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(iii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (r)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (r)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

+ Details

Earnings per Share - Summary of Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Numerator (in millions):
Net income available to common stockholders	$ 116.6	$ 35.6	$ 139.1
Denominator (in thousands):
Weighted average common shares outstanding	24,880	24,932	24,851
Dilutive effect of stock options and awards	113	187	171
Denominator for diluted earnings per share	24,993	25,119	25,022
Net income per share, basic:	$ 4.69	$ 1.43	$ 5.6
Net income per share, diluted:	$ 4.67	$ 1.42	$ 5.56

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482662/260-10-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-4

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 9
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-9

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 17
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480336/718-10-65-17

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-6

Reference 8: http://www.xbrl.org/2003/role/exampleRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 52
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482635/260-10-55-52

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 60
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476176/805-60-65-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-3

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482635/260-10-55-15

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-11

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-11

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-7

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482689/260-10-45-2

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 60B
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482689/260-10-45-60B

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482689/260-10-45-10

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(25))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(27))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(23))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482689/260-10-45-7

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (f)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481538/470-20-65-4

+ Details

- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482662/260-10-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-4

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 9
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-9

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 17
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480336/718-10-65-17

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-6

Reference 8: http://www.xbrl.org/2003/role/exampleRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 52
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482635/260-10-55-52

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 60
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476176/805-60-65-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-3

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482635/260-10-55-15

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-11

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-11

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-7

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482689/260-10-45-2

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 60B
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482689/260-10-45-60B

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(25))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(27))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(23))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482689/260-10-45-7

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (f)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481538/470-20-65-4

+ Details

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 235
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478671/942-235-S50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 235
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-05(b)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477314/942-235-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(i))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(k)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 9
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-9

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 17
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480336/718-10-65-17

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-6

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-9

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 60
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476176/805-60-65-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481687/323-10-50-3

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-1

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-8

Reference 18: http://www.xbrl.org/2003/role/exampleRef
-Topic 946
-SubTopic 830
-Name Accounting Standards Codification
-Section 55
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479168/946-830-55-11

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 205
-Name Accounting Standards Codification
-Section 45
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478009/946-205-45-3

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479105/946-220-45-7

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(16))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(9))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(1)(d))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 810
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 19
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481231/810-10-45-19

Reference 25: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-6

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(i))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1A

Reference 27: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(ii))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1A

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iii)(A))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1A

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iv))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1A

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(5))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1A

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(i))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1B

Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(A))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1B

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(B))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1B

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iv))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1B

Reference 35: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(5))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1B

Reference 36: http://www.xbrl.org/2003/role/disclosureRef
-Topic 205
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483499/205-20-50-7

Reference 37: http://www.xbrl.org/2003/role/exampleRef
-Topic 810
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 4J
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481175/810-10-55-4J

Reference 38: http://www.xbrl.org/2003/role/exampleRef
-Topic 810
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 4K
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481175/810-10-55-4K

Reference 39: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-1A

Reference 40: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-1B

Reference 41: http://www.xbrl.org/2003/role/disclosureRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-2

Reference 42: http://www.xbrl.org/2003/role/disclosureRef
-Topic 810
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481203/810-10-50-1A

Reference 43: http://www.xbrl.org/2003/role/disclosureRef
-Topic 810
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481203/810-10-50-1A

Reference 44: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (f)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481538/470-20-65-4

+ Details

Goodwill (Tables)

12 Months Ended

Dec. 31, 2025

Goodwill and Intangible Assets Disclosure [Abstract]

Summary of Goodwill

The following table analyzes goodwill movement for 2025 and 2024.


(in millions)	Performance Chemicals			Fuel Specialties			Oilfield Services			Total
At December 31, 2023
Gross cost	$	146.9		$	207.6		$	44.8		$	399.3
Accumulated impairment losses		—			—			—			—
Net book amount	$	146.9		$	207.6		$	44.8		$	399.3
Adjustment to the acquired fair values		(3.1	)		—			—			(3.1	)
Exchange effect		(13.7	)		(0.1	)		0.1			(13.7	)
At December 31, 2024
Gross cost	$	130.1		$	207.5		$	44.9		$	382.5
Accumulated impairment losses		—			—			—			—
Net book amount	$	130.1		$	207.5		$	44.9		$	382.5
Additions		—			—			2.0			2.0
Exchange effect		14.4			0.2			(0.1	)		14.5
At December 31, 2025
Gross cost	$	144.5		$	207.7		$	46.8		$	399.0
Accumulated impairment losses		—			—			—			—
Net book amount	$	144.5		$	207.7		$	46.8		$	399.0

- Definition

Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 24
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482548/350-20-55-24

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1A

Reference 12: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-2

+ Details

Leases - Components of Lease Expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Leases [Line Items]
Operating lease cost	$ 18.2	$ 17.1	$ 17.9
Short-term lease cost	7.7	8.7	8.1
Total lease cost	$ 25.9	$ 25.8	$ 26.0

Goodwill - Summary of Goodwill (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Goodwill [Line Items]
Gross cost, beginning balance	$ 382.5	$ 399.3
Accumulated impairment losses, beginning balance	0.0	0.0
Net book amount, beginning balance	382.5	399.3
Additions	2.0
Adjustment to the acquired fair values		(3.1)
Exchange effect	14.5	(13.7)
Gross cost, ending balance	399.0	382.5
Accumulated impairment losses, ending balance	0.0	0.0
Net book amount, ending balance	399.0	382.5
Performance Chemicals [Member]
Goodwill [Line Items]
Gross cost, beginning balance	130.1	146.9
Accumulated impairment losses, beginning balance	0.0	0.0
Net book amount, beginning balance	130.1	146.9
Additions	0.0
Adjustment to the acquired fair values		(3.1)
Exchange effect	14.4	(13.7)
Gross cost, ending balance	144.5	130.1
Accumulated impairment losses, ending balance	0.0	0.0
Net book amount, ending balance	144.5	130.1
Fuel Specialties [Member]
Goodwill [Line Items]
Gross cost, beginning balance	207.5	207.6
Accumulated impairment losses, beginning balance	0.0	0.0
Net book amount, beginning balance	207.5	207.6
Additions	0.0
Adjustment to the acquired fair values		0.0
Exchange effect	0.2	(0.1)
Gross cost, ending balance	207.7	207.5
Accumulated impairment losses, ending balance	0.0	0.0
Net book amount, ending balance	207.7	207.5
Oilfield Services [Member]
Goodwill [Line Items]
Gross cost, beginning balance	44.9	44.8
Accumulated impairment losses, beginning balance	0.0	0.0
Net book amount, beginning balance	44.9	44.8
Additions	2.0
Adjustment to the acquired fair values		0.0
Exchange effect	(0.1)	0.1
Gross cost, ending balance	46.8	44.9
Accumulated impairment losses, ending balance	0.0	0.0
Net book amount, ending balance	$ 46.8	$ 44.9

Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2025

Property, Plant and Equipment [Abstract]

Schedule of Property, Plant and Equipment

Property, plant and equipment consists of the following:


(in millions)	2025			2024
Land	$	23.6		$	21.6
Buildings		109.7			88.7
Equipment		508.9			439.6
Work in progress		70.0			62.1
Total gross cost		712.2			612.0
Less accumulated depreciation and impairment		(426.1	)		(342.3	)
Total net book value	$	286.1		$	269.7

Share-Based Compensation Plans - Assumptions Used to Determine Grant-Date Fair Value of Options (Detail) - Black-Scholes Model [Member]	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	1.51%	1.13%	1.16%
Expected life	3 years	3 years	4 years
Volatility	27.00%	25.50%	39.70%
Risk free interest rate	4.16%	4.38%	4.47%

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(v)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(iii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(iv)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (l)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 35
-Paragraph 1D
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480483/718-10-35-1D

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 35
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480483/718-10-35-3

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(ii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(01)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(02)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(03)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(04)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(01)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(02)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(03)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

+ Details

Other Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Sep. 30, 2025	Jun. 30, 2024	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Finite-Lived Intangible Assets [Line Items]
Amortization expense			$ 11.6	$ 12.6	$ 10.6
Cost of goods, amortization			1.7	2.3	$ 2.3
Additional completion costs			$ 4.2
Economic life of the ERP system			12 years
Intangible asset capitalized			$ 23.6	24.3
Impairment of intangible assets			19.0	0.0
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Impairment of intangible assets	$ 19.1
Software Development [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible asset capitalized			$ 23.6	$ 20.8
QGP Quimica Geral [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible asset capitalized		$ 3.5
Useful life of other intangible assets		7 years			10 years

Pension and Post-Employment Benefits - Fair Value of Pension Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Fair value of pension assets
Total plan assets	$ 0.0	$ 2.4
Non-US [Member]
Fair value of pension assets
Cash		2.5
Total plan assets		2.5
Non-US [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair value of pension assets
Cash		2.5
Total plan assets		2.5
Non-US [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Fair value of pension assets
Total plan assets		0.0
Non-US [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Fair value of pension assets
Total plan assets		$ 0.0

- Definition

Amount of asset, recognized in statement of financial position, for overfunded defined benefit pension and other postretirement plans.

+ References + Details

Segment Reporting and Geographical Area Data - Summary of Segment Reporting related to Cost of Goods Sold (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Segment Reporting Information [Line Items]
Total cost of goods sold	$ 1,285.6	$ 1,302.5	$ 1,357.7
Operating Segments [Member] \| Performance Chemicals [Member]
Segment Reporting Information [Line Items]
Total cost of goods sold	559.4	505.3	456.0
Operating Segments [Member] \| Fuel Specialties [Member]
Segment Reporting Information [Line Items]
Total cost of goods sold	449.3	461.2	480.8
Operating Segments [Member] \| Oilfield Services [Member]
Segment Reporting Information [Line Items]
Total cost of goods sold	$ 276.9	$ 336.0	$ 420.9

- Definition

The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

+ References + Details

Segment Reporting and Geographical Area Data (Tables)

12 Months Ended

Dec. 31, 2025

Segment Reporting [Abstract]

Segment Reporting

The following table analyzes financial information by the Company’s reportable segments:


(in millions)	2025			2024			2023
Net Sales:
Personal Care	$	409.2		$	390.0		$	352.7
Home Care		109.0			106.6			86.8
Other		163.2			157.1			122.1
Performance Chemicals		681.4			653.7			561.6
Refinery and Performance		509.4			517.4			540.6
Other		192.1			183.7			155.3
Fuel Specialties		701.5			701.1			695.9
Oilfield Services		395.1			490.6			691.3
Total net sales	$	1,778.0		$	1,845.4		$	1,948.8
Gross profit:
Performance Chemicals		122.0			148.4			105.6
Fuel Specialties		252.2			239.9			215.1
Oilfield Services		118.2			154.6			270.4
Total gross profit	$	492.4		$	542.9		$	591.1
Operating income/(expense):
Performance Chemicals	$	61.0		$	82.9		$	54.5
Fuel Specialties		144.8			129.6			109.7
Oilfield Services		23.3			38.8			78.6
Corporate costs		(72.8	)		(70.2	)		(81.2	)
Adjustment to fair value of contingent consideration		15.9			(3.4	)		—
Restructuring charge		(0.9	)		—			—
Impairment of property, plant and equipment		(22.9	)		—			—
Impairment of intangible assets		(19.1	)		—			—
Profit on disposal of property, plant and equipment		0.2			0.2			—
Total operating income	$	129.5		$	177.9		$	161.6
Identifiable assets at year-end:
Performance Chemicals	$	602.0		$	598.3
Fuel Specialties		625.5			553.8
Oilfield Services		212.2			272.5
Corporate		392.7			310.1
Total assets	$	1,832.4		$	1,734.7

Summary of Segment Reporting related to Cost of Goods Sold

The following table analyzes cost of goods sold by the Company’s reportable segments:


(in millions)	2025		2024		2023
Performance Chemicals	$	559.4	$	505.3	$	456.0
Fuel Specialties		449.3		461.2		480.8
Oilfield Services		276.9		336.0		420.9
Total cost of goods sold	$	1,285.6	$	1,302.5	$	1,357.7

Summary of Segment Reporting related to Selling, General and Administrative Expense and Research and Development Expense

The following table analyzes selling, general and administrative expenses and research and development expenses by the Company’s reportable segments:


(in millions)	2025		2024		2023
Performance Chemicals	$	61.0	$	65.5	$	51.1
Fuel Specialties		107.4		110.3		105.4
Oilfield Services		94.9		115.8		191.8
Corporate		72.8		70.2		81.2
Total selling, general and administrative expenses and research and development expenses	$	336.1	$	361.8	$	429.5

Summary of Segment Depreciation and Amortization

The following tables analyze sales and other financial information by location:


(in millions)	2025			2024			2023
Net sales by source:
United States	$	951.7		$	1,039.7		$	1,227.2
United Kingdom		793.2			823.4			857.7
Rest of World		379.0			288.9			199.4
Sales between areas		(345.9	)		(306.6	)		(335.5	)
	$	1,778.0		$	1,845.4		$	1,948.8
Income before income taxes:
United States	$	25.9		$	90.2		$	95.2
United Kingdom		67.3			(24.6	)		59.1
Rest of World		44.9			(24.4	)		20.1
	$	138.1		$	41.2		$	174.4
Long-lived assets at year-end:
United States	$	132.6		$	156.2
United Kingdom		121.3			88.0
Rest of World		150.4			133.6
	$	404.3		$	377.8
Identifiable assets at year-end:
United States	$	555.9		$	593.6
United Kingdom		579.1			488.2
Rest of World		298.4			270.4
Goodwill		399.0			382.5
	$	1,832.4		$	1,734.7

Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2025

Equity [Abstract]

Stockholders' Equity


	Common Stock						Treasury Stock
(number of shares in thousands)	2025		2024		2023		2025			2024			2023
At January 1		29,554.5		29,554.5		29,554.5		4,595			4,687			4,789
Exercise of options		—		—		—		(82	)		(97	)		(113	)
Stock purchases		—		—		—		264			5			11
At December 31		29,554.5		29,554.5		29,554.5		4,777			4,595			4,687