v3.26.1
Long-term debt - Valhi Contran Credit Facility - Additional Information (Details) - USD ($)
$ in Millions
6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Long-term debt    
Repayments of credit facility $ 255.3 $ 280.9
VALHI, INC. | Contran Credit Facility    
Long-term debt    
Borrowings 0.0  
Repayments of credit facility $ 16.0  
Debt instrument, interest rate during period 7.75%  
Debt instrument, Interest rate at period end 7.75%  
Amount available for borrowing $ 117.4