Annual report pursuant to Section 13 and 15(d)

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

v3.3.1.900
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, 2015
Dec. 31, 2014
Dec. 31, 2013
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 $ 2.25 $ 2.03 $ 1.85
Risk-free interest rate 0.09% 0.05% 0.09%
Volatility 32.65% 47.75% 39.24%
Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Weighted-average grant date fair value per share $ 5.02 $ 2.47 $ 2.09
Risk-free interest rate 0.33% 0.07% 0.10%
Volatility 59.14% 46.82% 41.58%