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Stockholders' Equity - Summary of Assumptions Used to Value Stock Option Grants Using Lattice-Binomial Model (Details)
$ / shares in Units, $ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2017
USD ($)
$ / shares
Jun. 30, 2016
USD ($)
$ / shares
Jun. 30, 2017
USD ($)
$ / shares
Jun. 30, 2016
USD ($)
$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based payment award, expiration period (in years)     10 years  
Dividend yield 0.00% 0.00% 0.00% 0.00%
Expected volatility 34.00% 45.00%    
Risk-free interest rate 2.37% 1.83%    
Suboptimal exercise factor 2.51 2.48   2.48
Weighted-average fair value (in dollars per share) | $ / shares $ 67.21 $ 48.38 $ 64.67 $ 49.52
Stock-based compensation expense $ 44,028 $ 44,112 $ 88,916 $ 86,534
Total income tax impact on provision (in thousands) $ 14,477 $ 16,571 $ 29,178 $ 32,534
Minimum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expected volatility     34.00% 45.00%
Risk-free interest rate     2.37% 1.83%
Suboptimal exercise factor     2.48  
Maximum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expected volatility     37.00% 50.00%
Risk-free interest rate     2.45% 2.04%
Suboptimal exercise factor     2.51