v3.26.1
Noncontrolling interest in subsidiaries - Noncontrolling Interest in Net Assets of Subsidiaries (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Noncontrolling interest in net assets:    
Noncontrolling interest in subsidiaries $ 355.1 $ 340.5
Kronos Worldwide    
Noncontrolling interest in net assets:    
Noncontrolling interest in subsidiaries 197.4 197.6
NLI Holdings    
Noncontrolling interest in net assets:    
Noncontrolling interest in subsidiaries 75.8 75.1
CompX International    
Noncontrolling interest in net assets:    
Noncontrolling interest in subsidiaries 18.8 18.0
BMI    
Noncontrolling interest in net assets:    
Noncontrolling interest in subsidiaries 30.0 25.0
LandWell    
Noncontrolling interest in net assets:    
Noncontrolling interest in subsidiaries $ 33.1 $ 24.8