CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
Net sales	$ 37,971	$ 41,151
Cost of sales	28,304	28,447
Gross margin	9,667	12,704
Selling, general and administrative expense	5,952	5,664
Other operating income (expense):
Corporate expense	2,359	2,843
Income from operations	1,356	4,197
Equity in earnings (losses) of Kronos Worldwide, Inc.	2,476	(4,637)
Other income (expense):
Interest and dividend income	2,551	1,965
Marketable equity securities	2,383	(5,498)
Other components of net periodic pension and OPEB cost	(318)	(346)
Interest expense	(145)	(199)
Income (loss) before income taxes	8,303	(4,518)
Income tax expense	988	1,421
Net income (loss)	7,315	(5,939)
Noncontrolling interest in net income of subsidiary	476	777
Net income (loss) attributable to NL stockholders	$ 6,839	$ (6,716)
Amounts attributable to NL stockholders:
Net income (loss) per basic share	$ 0.14	$ (0.14)
Net income (loss) per diluted share	$ 0.14	$ (0.14)
Weighted average shares outstanding - basic	48,833	48,816
Weighted average shares outstanding - diluted	48,833	48,816