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Stock Options, Employee Stock Purchase Plan and Restricted Stock - Weighted-average Assumptions for Stock Options (Details) - $ / shares
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected life (in years) 4 years 9 months 18 days 4 years 1 month 6 days 4 years
Risk-free interest rate 1.50%    
Fair value per stock option (in Dollars per share) $ 14.59 $ 12.89 $ 6.95
Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected volatility 42.00% 40.00% 49.00%
Risk-free interest rate   0.90% 0.70%
Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected volatility 47.00% 71.00% 68.00%
Risk-free interest rate 1.60% 2.20% 1.40%