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Schedule of Intangible Assets (Details) - USD ($)
$ in Millions
9 Months Ended
Sep. 30, 2021
Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]    
Amortizable intangible assets, gross $ 123.5 $ 123.5
Accumulated intangible asset amortization (66.1) (60.7)
Amortizable intangible assets, net $ 57.4 62.8
Average useful life of finite-lived intangible assets 15 years  
Contract-Based Intangible Assets [Member]    
Finite-Lived Intangible Assets [Line Items]    
Amortizable intangible assets, gross $ 54.6 54.6
Accumulated intangible asset amortization (34.0) (32.0)
Amortizable intangible assets, net 20.6 22.6
Customer-Related Intangible Assets [Member]    
Finite-Lived Intangible Assets [Line Items]    
Amortizable intangible assets, gross 68.9 68.9
Accumulated intangible asset amortization (32.1) (28.7)
Amortizable intangible assets, net $ 36.8 $ 40.2