v3.26.1
Inventories (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Inventory [Line Items]    
Materials and supplies, net $ 180.2 $ 161.6
Raw coal 76.3 95.6
Saleable coal 183.8 126.0
Inventories, net $ 440.3 $ 383.2