Income taxes (Tables)

12 Months Ended

Dec. 31, 2024

Income taxes

Schedule of Income Taxes

	Years ended December 31,
	2022		2023		2024
	(In thousands)
Expected tax expense (benefit), at U.S. federal statutory   income tax rate of 21%	$	8,241	$	(1,348)	$	17,497
Nontaxable dividends received from Kronos		(5,621)		(5,621)		(3,550)
U.S. state income taxes and other, net		165		(32)		110
Income tax expense (benefit)	$	2,785	$	(7,001)	$	14,057
Components of income tax expense (benefit):
Currently payable	$	495	$	307	$	340
Deferred income tax expense (benefit)		2,290		(7,308)		13,717
Income tax expense (benefit)	$	2,785	$	(7,001)	$	14,057
Comprehensive provision (benefit) for income taxes allocable to:
Net income (loss)	$	2,785	$	(7,001)	$	14,057
Other comprehensive income (loss):
Currency translation		(1,849)		241		(2,207)
Pension plans		6,542		(291)		1,251
Other		69		(35)		(28)
Total	$	7,547	$	(7,086)	$	13,073

Schedule of Components of Net Deferred Tax Liability

	December 31,
	2023				2024
	Assets		Liabilities		Assets		Liabilities
	(In thousands)
Tax effect of temporary differences related to:
Marketable securities	$	—	$	(3,586)	$	—	$	(5,652)
Goodwill		—		(1,693)		—		(1,693)
Accrued environmental liabilities		21,332		—		14,406		—
Other accrued liabilities and deductible differences		2,206		—		1,981		—
Other taxable differences		—		(3,859)		—		(5,733)
Investment in Kronos Worldwide, Inc.		—		(56,133)		—		(56,700)
Adjusted gross deferred tax assets (liabilities)		23,538		(65,271)		16,387		(69,778)
Netting of items by tax jurisdiction		(23,538)		23,538		(16,387)		16,387
Net noncurrent deferred tax liability	$	—	$	(41,733)	$	—	$	(53,391)