CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 136.1	$ 197.7	$ 89.0
Other comprehensive income (loss), net of tax:
Currency translation	(26.1)	(6.8)	12.5
Defined benefit pension plans	89.4	45.3	(10.4)
Other	1.0	(0.3)	(0.7)
Total other comprehensive income, net	64.3	38.2	1.4
Comprehensive income	200.4	235.9	90.4
Comprehensive income attributable to noncontrolling interest	62.8	80.6	33.9
Comprehensive income attributable to Valhi stockholders	$ 137.6	$ 155.3	$ 56.5