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Intangible Assets (Gross and Net Intangible Assets) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2022
Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount $ 40.0 $ 40.0
Accumulated Amortization 10.2 8.2
Total $ 29.8 31.8
Customer relationships    
Finite-Lived Intangible Assets [Line Items]    
Weighted - Average Remaining Amortization Years 2 years  
Gross Carrying Amount $ 6.7 6.7
Accumulated Amortization 5.6 5.0
Total $ 1.1 1.7
Permits    
Finite-Lived Intangible Assets [Line Items]    
Weighted - Average Remaining Amortization Years 20 years  
Gross Carrying Amount $ 31.7 31.7
Accumulated Amortization 4.5 3.1
Total $ 27.2 28.6
Other    
Finite-Lived Intangible Assets [Line Items]    
Weighted - Average Remaining Amortization Years 28 years  
Gross Carrying Amount $ 1.6 1.6
Accumulated Amortization 0.1 0.1
Total $ 1.5 $ 1.5