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Stock Options, Restricted Stock Units and Employee Stock Purchase Plan - Additional Information (Details) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Apr. 27, 2017
May 02, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Number of options granted (in Shares) 0          
Exercise of stock options (in Shares) 400,000 1,500,000 500,000 1,500,000    
Proceeds from stock options exercised $ 5,900,000 $ 9,900,000 $ 7,100,000 $ 9,900,000    
Tax benefit from compensation expense $ 6,100,000 $ 36,600,000 $ 6,900,000 $ 36,600,000    
Restricted stock units            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Annual award vesting percentage     25.00%      
Award vesting period     4 years      
Number of unit granted (in Shares)     662,000      
Omnibus Plan            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Number of shares available for issuance (in Shares)         8,000,000  
2014 Plan            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Number of shares reserved for issuance (in Shares)           7,500,000
Employee Stock Purchase Plan ESPP            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Number of shares reserved for issuance (in Shares) 2,000,000   2,000,000      
Discount from market price at the beginning or end of the offering period     15.00%      
Maximum annual purchase per employee under ESPP     $ 25,000      
Maximum annual withholdings per employee for purchases under ESPP     $ 21,250      
Maximum number of shares available for purchase per employee (in Shares)     15,000      
Contributions from plan participants through payroll deductions     $ 1,700,000      
Employee Stock Purchase Plan ESPP | Minimum            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Percentage of base wages withheld for purchase of stock     1.00%      
Employee Stock Purchase Plan ESPP | Maximum            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Percentage of base wages withheld for purchase of stock     15.00%