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Asset Retirement Obligations (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Loss Contingencies [Line Items]      
Asset retirement obligation $ 19.0 $ 24.0 $ 23.7
Revisions of estimates $ 0.0 (0.2)  
Buyer of Formerly-Owned Business      
Loss Contingencies [Line Items]      
Revisions of estimates   (4.3)  
Facility Idling      
Loss Contingencies [Line Items]      
Revisions of estimates   $ 4.1