Noncontrolling Interest in Subsidiaries - Noncontrolling Interest in Net Assets of Subsidiaries (Detail) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Noncontrolling interest in net assets:
Noncontrolling interest in subsidiaries	$ 348.2	$ 328.9
Kronos Worldwide, Inc.
Noncontrolling interest in net assets:
Noncontrolling interest in subsidiaries	239.3	226.6
NL Industries
Noncontrolling interest in net assets:
Noncontrolling interest in subsidiaries	79.0	75.7
CompX International
Noncontrolling interest in net assets:
Noncontrolling interest in subsidiaries	20.6	22.5
BMI
Noncontrolling interest in net assets:
Noncontrolling interest in subsidiaries	6.9	8.3
LandWell
Noncontrolling interest in net assets:
Noncontrolling interest in subsidiaries	$ 2.4	$ (4.2)