v3.25.4
Long-term debt - Kronos 3.75 Senior Secured Notes - Additional Information (Details) - Kronos Worldwide - 3.75% Senior Secured Notes due 2025 - EUR (€)
€ in Millions
Dec. 31, 2025
Sep. 30, 2025
Sep. 15, 2025
Dec. 31, 2024
Feb. 12, 2024
Long-term debt          
Debt instrument interest rate     3.75%   3.75%
Debt instrument principal amount     € 75   € 325
Kronos International, Inc          
Long-term debt          
Debt instrument interest rate 3.75% 3.75%   3.75%  
Debt instrument principal amount € 75 € 75