Income taxes (Tables)

12 Months Ended

Dec. 31, 2025

Income taxes

Schedule of Income Taxes

	Years ended December 31,
	2023		2024		2025
	(In thousands)
Components of income tax expense (benefit):
Current income tax expense
U.S. federal	$	247	$	266	$	67
State		60		74		101
		307		340		168
Deferred income taxes (benefit)
U.S. federal		(7,306)		13,720		(16,217)
State		(2)		(3)		(4)
		(7,308)		13,717		(16,221)
Income tax expense (benefit)	$	(7,001)	$	14,057	$	(16,053)
Comprehensive provision (benefit) for income taxes allocable to:
Net income (loss)	$	(7,001)	$	14,057	$	(16,053)
Other comprehensive income (loss):
Currency translation		241		(2,207)		2,103
Defined benefit pension plans		(291)		1,251		10,022
Other		(35)		(28)		27
Comprehensive income tax expense (benefit)	$	(7,086)	$	13,073	$	(3,901)

Schedule of Components of Net Deferred Tax Liability

	December 31,
	2024				2025
	Assets		Liabilities		Assets		Liabilities
	(In thousands)
Tax effect of temporary differences related to:
Marketable securities	$	—	$	(5,652)	$	—	$	(2,799)
Goodwill		—		(1,693)		—		(1,693)
Accrued environmental liabilities		14,406		—		2,831		—
Other accrued liabilities and deductible differences		1,981		—		2,138		—
Other taxable differences		—		(5,733)		—		(2,945)
Investment in Kronos Worldwide, Inc.		—		(56,700)		—		(52,460)
Tax loss carryforwards		—		—		825		—
Adjusted gross deferred tax assets (liabilities)		16,387		(69,778)		5,794		(59,897)
Netting of items by tax jurisdiction		(16,387)		16,387		(5,794)		5,794
Net noncurrent deferred tax liability	$	—	$	(53,391)	$	—	$	(54,103)