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, 2022	$ 6,101	$ 298,598	$ 300,442	$ (222,991)	$ 20,597	$ 402,747
Net income (loss)			(9,824)		1,294	(8,530)
Other comprehensive 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 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
Beginning Balance at Dec. 31, 2023	6,103	298,868	284,462	(219,621)	21,950	391,762
Net income (loss)			14,674		1,094	15,768
Other comprehensive loss, net of tax				(3,813)		(3,813)
Issuance of NL common stock	2	98				100
Dividends paid			(7,814)			(7,814)
Dividends paid to noncontrolling interest					(936)	(936)
Other, net		133			16	149
Ending Balance at Jun. 30, 2024	6,105	299,099	291,322	(223,434)	22,124	395,216
Beginning Balance at Mar. 31, 2024	6,103	298,868	287,395	(224,240)	21,958	390,084
Net income (loss)			7,835		618	8,453
Other comprehensive loss, net of tax				806	1	807
Issuance of NL common stock	2	98				100
Dividends paid			(3,908)			(3,908)
Dividends paid to noncontrolling interest					(469)	(469)
Other, net		133			16	149
Ending Balance at Jun. 30, 2024	$ 6,105	$ 299,099	$ 291,322	$ (223,434)	$ 22,124	$ 395,216