CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
CONDENSED CONSOLIDATED STATEMENTS OF INCOME
Net sales	$ 40,569	$ 40,272
Cost of sales	27,317	28,109
Gross margin	13,252	12,163
Selling, general and administrative expense	6,202	6,294
Corporate expense	2,943	2,721
Income from operations	4,107	3,148
Equity in earnings (losses) of Kronos Worldwide, Inc.	(1,477)	5,525
Other income (expense):
Interest and dividend income	1,252	2,038
Marketable equity securities	2,695	(8,552)
Other components of net periodic pension and OPEB cost		(285)
Interest expense	(11)	(575)
Income before income taxes	6,566	1,299
Income tax expense (benefit)	1,472	(23)
Net income	5,094	1,322
Noncontrolling interest in net income of subsidiary	750	655
Net income attributable to NL stockholders	$ 4,344	$ 667
Amounts attributable to NL stockholders:
Basic net income per share	$ 0.09	$ 0.01
Diluted net income per share	$ 0.09	$ 0.01
Weighted average shares used in the calculation of net income per share - basic	48,863	48,848
Weighted average shares used in the calculation of net income per share - diluted	48,863	48,848