CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive loss	Noncontrolling interest in subsidiary	Total
Beginning Balance at Dec. 31, 2021	$ 6,100	$ 299,775	$ 297,351	$ (240,756)	$ 22,501	$ 384,971
Net income (loss)			33,844		2,612	36,456
Other comprehensive income (loss), net of tax				17,765		17,765
Issuance of NL common stock	1	119				120
Dividends paid			(30,753)			(30,753)
Dividends paid to noncontrolling interest					(4,304)	(4,304)
Other, net		(1,296)			(212)	(1,508)
Ending Balance at Dec. 31, 2022	6,101	298,598	300,442	(222,991)	20,597	402,747
Net income (loss)			(2,308)		2,890	582
Other comprehensive income (loss), net of tax				3,370	18	3,388
Issuance of NL common stock	2	98				100
Dividends paid			(13,672)			(13,672)
Dividends paid to noncontrolling interest					(1,555)	(1,555)
Other, net		172				172
Ending Balance at Dec. 31, 2023	6,103	298,868	284,462	(219,621)	21,950	391,762
Net income (loss)			67,228		2,033	69,261
Other comprehensive income (loss), net of tax				(3,735)		(3,735)
Issuance of NL common stock	2	98				100
Dividends paid			(36,634)			(36,634)
Dividends paid to noncontrolling interest					(5,000)	(5,000)
Other, net		133			16	149
Ending Balance at Dec. 31, 2024	$ 6,105	$ 299,099	$ 315,056	$ (223,356)	$ 18,999	$ 415,903