CONDENSED CONSOLIDATED STATEMENTS OF 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)			48,809		1,457	50,266
Other comprehensive income (loss), net of tax				(5,563)		(5,563)
Issuance of NL common stock	1	119				120
Dividends paid			(6,833)			(6,833)
Dividends paid to noncontrolling interest					(812)	(812)
Other, net		(962)			(210)	(1,172)
Ending Balance at Jun. 30, 2022	6,101	298,932	339,327	(246,319)	22,936	420,977
Beginning Balance at Mar. 31, 2022	6,100	300,210	312,492	(238,371)	22,747	403,178
Net income (loss)			30,252		805	31,057
Other comprehensive income (loss), net of tax				(7,948)		(7,948)
Issuance of NL common stock	1	119				120
Dividends paid			(3,417)			(3,417)
Dividends paid to noncontrolling interest					(406)	(406)
Other, net		(1,397)			(210)	(1,607)
Ending Balance at Jun. 30, 2022	6,101	298,932	339,327	(246,319)	22,936	420,977
Beginning Balance at Dec. 31, 2022	6,101	298,598	300,442	(222,991)	20,597	402,747
Net income (loss)			(9,824)		1,294	(8,530)
Other comprehensive income (loss), net of tax				1,893	4	1,897
Issuance of NL common stock	2	98				100
Dividends paid			(6,834)			(6,834)
Dividends paid to noncontrolling interest					(778)	(778)
Other, net		172				172
Ending Balance at Jun. 30, 2023	6,103	298,868	283,784	(221,098)	21,117	388,774
Beginning Balance at Mar. 31, 2023	6,101	298,252	290,309	(224,368)	20,982	391,276
Net income (loss)			(3,108)		517	(2,591)
Other comprehensive income (loss), net of tax				3,270	8	3,278
Issuance of NL common stock	2	98				100
Dividends paid			(3,417)			(3,417)
Dividends paid to noncontrolling interest					(390)	(390)
Other, net		518				518
Ending Balance at Jun. 30, 2023	$ 6,103	$ 298,868	$ 283,784	$ (221,098)	$ 21,117	$ 388,774