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Share-Based Compensation - Schedule of Fair Value Options Granted and Assumptions (Details) - Stock Options - USD ($)
$ / shares in Units, $ in Millions
9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Share-based Compensation    
Stock options granted, fair value $ 0.8 $ 16.4
Stock options, expiration period (in years) 7 years  
Stock options granted, weighted average fair value (in dollar per share) $ 48.05 $ 39.02
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]    
Dividend yield 0.50% 0.00%
Expected volatility 28.00% 30.70%
Risk-fee interest rate 2.10% 1.60%
Expected life of options (in years) 5 years 8 months 12 days 5 years 8 months 12 days
Forfeiture rate 0.00% 0.00%
Minimum    
Share-based Compensation    
Stock options, vesting period (in years) 3 years  
Maximum    
Share-based Compensation    
Stock options, vesting period (in years) 4 years