v3.22.2
BASIS OF PRESENTATION - AOCL and Accumulated Depreciation and Amortization (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2022
Jun. 30, 2021
Dec. 31, 2021
Accumulated other comprehensive loss        
Balance at the beginning of the period $ (2,287.0) $ (1,789.5) $ (2,858.2)  
Realized loss on foreign currency transactions reclassified into investment expense (income), net of tax (0.9)   (0.9)  
Balance at the end of the period (1,404.7) (2,326.8) (1,404.7)  
Accumulated depreciation and amortization        
Accumulated depreciation   2,680.0   $ 2,583.4
Accumulated amortization   42.0   $ 41.2
Foreign Currency        
Accumulated other comprehensive loss        
Balance at the beginning of the period   (19.0)    
Other comprehensive income (loss)   (52.3)    
Balance at the end of the period   (71.3)    
Pension and Other Benefits (recorded in G&A : Other)        
Accumulated other comprehensive loss        
Balance at the beginning of the period   (9.1)    
Other comprehensive income (loss)   0.2    
Balance at the end of the period   (8.9)    
Accumulated Other Comprehensive Income (Loss)        
Accumulated other comprehensive loss        
Balance at the beginning of the period (12.3) (28.1) 38.7  
Other comprehensive income (loss)   (52.1)    
Balance at the end of the period $ 8.2 $ (80.2) $ 8.2