CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Common stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income (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			25,954		1,217	27,171
Other comprehensive income , net of tax				3,107		3,107
Issuance of NL common stock	2	99				101
Dividends paid			(5,855)			(5,855)
Dividends paid to noncontrolling interest					(669)	(669)
Other, net		1,117			(1,746)	(629)
Ending Balance at Jun. 30, 2021	6,100	300,309	277,974	(248,082)	22,274	358,575
Beginning Balance at Mar. 31, 2021	6,098	300,097	268,205	(249,564)	21,983	346,819
Net income			12,697		608	13,305
Other comprehensive income , net of tax				1,482		1,482
Issuance of NL common stock	2	99				101
Dividends paid			(2,928)			(2,928)
Dividends paid to noncontrolling interest					(330)	(330)
Equity transactions with noncontrolling interest, net and other		113			13	126
Ending Balance at Jun. 30, 2021	6,100	300,309	277,974	(248,082)	22,274	358,575
Beginning Balance at Dec. 31, 2021	6,100	299,775	297,351	(240,756)	22,501	384,971
Net income			48,809		1,457	50,266
Other comprehensive income , 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			30,252		805	31,057
Other comprehensive income , 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