v3.26.1
Equity Method Investments (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Schedule of Equity Method Investments [Line Items]          
Equity method investments $ 35.3   $ 35.3   $ 47.5
Loss from equity affiliates 9.9 $ 0.9 15.6 $ 7.6  
Middlemount Mine          
Schedule of Equity Method Investments [Line Items]          
Equity method investments 35.3   35.3   47.5
Loss from equity affiliates 9.3 0.5 13.8 6.8  
R3 Renewables II          
Schedule of Equity Method Investments [Line Items]          
Equity method investments 0.0   0.0   $ 0.0
Loss from equity affiliates $ 0.6 $ 0.4 $ 1.8 $ 0.8