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, 2020	$ 6,098	$ 299,093	$ 257,875	$ (251,189)	$ 23,472	$ 335,349
Net income			51,188		2,172	53,360
Other comprehensive income, net of tax				10,433		10,433
Issuance of NL common stock	2	99				101
Dividends paid			(11,712)			(11,712)
Dividends paid to noncontrolling interest					(1,324)	(1,324)
Other, net		583			(1,819)	(1,236)
Ending Balance at Dec. 31, 2021	6,100	299,775	297,351	(240,756)	22,501	384,971
Net income			33,844		2,612	36,456
Other comprehensive income, 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			(2,308)		2,890	582
Other comprehensive income, 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