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Share-Based Compensation Plans - Additional Information (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Shares available to be granted 7.2    
Unrecognized share-based compensation expense $ 50.6    
Unrecognized share-based compensation expense, period of recognition 1 year 9 months 18 days    
Service-based Restricted Share Units      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vested, total fair value $ 25.6 $ 24.6 $ 14.5
Granted, weighted average grant date fair value (in dollars per share) $ 47.48 $ 81.51 $ 70.55
Performance-based Restricted Share Units      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vested, total fair value $ 8.0 $ 2.4 $ 3.8
Granted, weighted average grant date fair value (in dollars per share) $ 47.54 $ 85.01 $ 70.34
RTSR      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Granted, weighted average grant date fair value (in dollars per share) $ 55.61 $ 101.13 $ 64.82
Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Award vesting period 1 year    
Maximum | RTSR      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Award vesting period 10 years