CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
CONDENSED CONSOLIDATED STATEMENTS OF INCOME
Net sales	$ 41,151	$ 42,050
Cost of sales	28,447	29,970
Gross margin	12,704	12,080
Selling, general and administrative expense	5,664	5,774
Other operating income (expense):
Corporate expense	2,843	2,436
Income from operations	4,197	3,870
Equity in earnings of Kronos Worldwide, Inc.	(4,637)	17,533
Other income (expense):
Interest and dividend income	1,965	309
Marketable equity securities	(5,498)	671
Other components of net periodic pension and OPEB cost	(346)	(223)
Interest expense	(199)	(246)
Income before income taxes	(4,518)	21,914
Income tax expense (benefit)	1,421	2,705
Net income	(5,939)	19,209
Noncontrolling interest in net income of subsidiary	777	652
Net income attributable to NL stockholders	$ (6,716)	$ 18,557
Amounts attributable to NL stockholders:
Net income (loss) per basic share	$ (0.14)	$ 0.38
Net income (loss) per diluted share	$ 0.82	$ 0.74
Weighted average shares outstanding - basic	48,816	48,803
Weighted average shares outstanding - diluted	48,809	48,795