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Asset Retirement Obligations Other Commitments (Details) - USD ($)
$ in Millions
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Jul. 27, 2018
Other Commitments [Line Items]        
Assets held-in-trust, current $ 1,749.3 $ 1,393.9 $ 1,315.2  
Asset retirement obligations 1,526.9 1,203.7    
Bonnie Facility Trust        
Other Commitments [Line Items]        
Asset retirement obligations       $ 21.0
Plant City and Bonnie Facilities [Member]        
Other Commitments [Line Items]        
Surety Bonds Outstanding Delivered To EPA 249.7      
Asset retirement obligations $ 262.9 $ 251.8