v3.23.2
BASIS OF PRESENTATION - AOCL and Accumulated Depreciation and Amortization (Details) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2023
Dec. 31, 2022
Accumulated other comprehensive loss    
Balance at the beginning of the period $ (2,624.5)  
Balance at the end of the period (2,582.6)  
Accumulated depreciation and amortization    
Accumulated depreciation 2,958.0 $ 2,853.8
Accumulated amortization 17.3 $ 22.2
Foreign Currency    
Accumulated other comprehensive loss    
Balance at the beginning of the period (78.8)  
Other comprehensive loss (47.2)  
Balance at the end of the period (126.0)  
Pension Benefits    
Accumulated other comprehensive loss    
Balance at the beginning of the period 1.5  
Other comprehensive loss (0.1)  
Balance at the end of the period 1.4  
Accumulated Other Comprehensive Income (Loss)    
Accumulated other comprehensive loss    
Balance at the beginning of the period (77.3)  
Other comprehensive loss (47.3)  
Balance at the end of the period $ (124.6)