Annual report pursuant to Section 13 and 15(d)

Equity-Based Compensation - Summary of Option Activity (Details)

Equity-Based Compensation - Summary of Option Activity (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Summary of option activity under stock plans    
Number of options outstanding, beginning balance (in shares) 31,286,787  
Number of options, granted (in shares) 7,945,500  
Number of options, exercised (in shares) (1,836,572)  
Number of options, forfeited (in shares) (1,472,314)  
Number of options, expired (in shares) (1,282,887)  
Number of options outstanding, ending balance (in shares) 34,640,514 31,286,787
Share-based Compensation Weighted Average Exercise Price [Abstract]    
Weighted average exercise price, beginning balance (in usd per share) $ 9.55  
Weighted average exercise price, granted (in usd per share) 10.22  
Weighted average exercise price, exercised (in usd per share) 4.67  
Weighted average exercise price, forfeited (in usd per share) 11.28  
Weighted average exercise price, expired (in usd per share) 1.53  
Weighted average exercise price, ending balance (in usd per share) $ 10.18 $ 9.55
Weighted average remaining contractual term, outstanding 6 years 9 months 15 days 6 years 11 months 19 days
Aggregate intrinsic value, outstanding $ 32,984 $ 63,902
Vested and expected to vest, number of options (in shares) 31,724,227  
Vested and expected to vest, weighted average exercise price (in usd per share) $ 10.07  
Weighted average expected to vest, remaining contractual term 6 years 7 months 21 days  
Aggregate intrinsic value, vested and expected to vest $ 32,477  
Number of options exercisable (in shares) 14,494,573  
Weighted average exercise price exercisable (in usd per share) $ 8.59  
Weighted average remaining contractual term, exercisable 4 years 6 months  
Exercisable, aggregate intrinsic value $ 29,385