v3.10.0.1
Share-based Compensation (Narrative) (Details) - USD ($)
1 Months Ended 3 Months Ended 6 Months Ended
Jun. 30, 2018
Mar. 31, 2018
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Percent of annual incentive compensation receivable in shares 100.00%   100.00%   100.00%  
Share-based compensation expense     $ 45,500,000 $ 51,400,000 $ 88,200,000 $ 80,300,000
2018 PSUs | PSUs            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Award grant (in shares) 2,228,560 1,114,280        
Award performance period         2 years  
Share-based compensation expense $ 0          
2018 PSUs | PSUs | April 1, 2020            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Award vesting rights         50.00%  
2018 PSUs | PSUs | October 1, 2020            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Award vesting rights         50.00%  
2018 PSUs | PSUs | Minimum            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Award performance range         50.00%  
Award expected performance 50.00%   50.00%   50.00%  
2018 PSUs | PSUs | Maximum            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Award performance range         125.00%  
Award expected performance 150.00%   150.00%   150.00%