Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation and Employee Benefit Plans - Fair Value of Employee Stock Purchase Rights (Details)

v3.6.0.2
Stock-Based Compensation and Employee Benefit Plans - Fair Value of Employee Stock Purchase Rights (Details) - Employee Stock Purchase Rights [Member] - $ / shares
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Dividend yield 0.00%   0.00%
Expected life (in years) 6 months 6 months 6 months
Minimum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Weighted-average grant date fair value per share $ 5.85 $ 2.25 $ 2.03
Risk-free interest rate 0.38% 0.09% 0.05%
Volatility 49.94% 32.65% 47.75%
Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Weighted-average grant date fair value per share $ 6.20 $ 5.02 $ 2.47
Risk-free interest rate 0.60% 0.33% 0.07%
Volatility 53.94% 59.14% 46.82%