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Commitments and Contingencies - Asset Retirement Obligations (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]    
Beginning balance $ 41.8 $ 38.3
Liabilities identified 0.0 2.3
Liabilities settled 0.0 (0.1)
Accretion expense 1.5 1.3
Ending balance $ 43.3 $ 41.8