v3.26.1
Long-term debt - Components of Long-Term Debt (Detail) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Long-term debt    
Revolving credit facility $ 28.2  
Total debt 569.6 $ 557.4
Total long-term debt 569.6 557.4
Related party    
Long-term debt    
Total long-term debt 53.7 53.7
Related party | Subordinated, Unsecured Term Loan from Contran    
Long-term debt    
Subordinated debt 53.7 53.7
Kronos International, Inc | 9.50% Senior Secured Notes due 2029    
Long-term debt    
Kronos International, Inc. $ 487.7 $ 503.7