v3.25.4
Fair value measurements and financial instruments - Financial Instruments not Carried at Fair Value (Details)
€ in Thousands, $ in Millions
Dec. 31, 2025
EUR (€)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Reported Value Measurement      
Fair value measurements and financial instruments      
Cash, cash equivalents and restricted cash equivalents   $ 228.7 $ 378.6
Estimate of Fair Value Measurement      
Fair value measurements and financial instruments      
Cash, cash equivalents and restricted cash equivalents   228.7 378.6
Kronos Worldwide | Kronos International, Inc      
Fair value measurements and financial instruments      
Long term debt, carrying amount     10.0
Long term debt, fair value     10.0
Kronos Worldwide | 9.50% Senior Secured Notes due 2029 | Kronos International, Inc      
Fair value measurements and financial instruments      
Long term debt, carrying amount € 426,174 503.7 365.4
Long term debt, fair value   469.9 403.4
Kronos Worldwide | 3.75% Senior Secured Notes due 2025 | Kronos International, Inc      
Fair value measurements and financial instruments      
Long term debt, carrying amount     78.3
Long term debt, fair value     77.9
LandWell | Bank note payable      
Fair value measurements and financial instruments      
Long term debt, carrying amount   10.7 11.4
Long term debt, fair value   $ 10.7 $ 11.4