v3.22.4
ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Change in AOCI by component (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Accumulated other comprehensive loss      
Balance at the beginning of the period $ (28.1)    
Realized loss on foreign currency transactions reclassified into investment expense (income)   $ (0.4) $ 1.9
Balance at the end of period (77.3) (28.1)  
Accumulated Other Comprehensive Income (Loss)      
Accumulated other comprehensive loss      
Balance at the beginning of the period (28.1) 38.7  
Other comprehensive income (loss) (49.2) (66.4)  
Realized loss on foreign currency transactions reclassified into investment expense (income)   (0.4)  
Balance at the end of period (77.3) (28.1) 38.7
Foreign Currency      
Accumulated other comprehensive loss      
Balance at the beginning of the period (19.0) 60.1  
Other comprehensive income (loss) (59.8) (78.7)  
Realized loss on foreign currency transactions reclassified into investment expense (income)   (0.4) 1.9
Balance at the end of period (78.8) (19.0) 60.1
Pension Benefits      
Accumulated other comprehensive loss      
Balance at the beginning of the period (9.1) (21.4)  
Other comprehensive income (loss) 10.6 12.3  
Balance at the end of period $ 1.5 $ (9.1) $ (21.4)