Share-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands |
12 Months Ended | |||
|---|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
Dec. 31, 2012 |
|
| Shares | ||||
| Outstanding at beginning of period | 19,924,405 | 20,540,273 | 17,707,139 | |
| Granted | 2,231,504 | 4,406,856 | 8,345,437 | |
| Exercised | (1,374,438) | 0 | (9,400) | |
| Canceled | (4,484,843) | (1,494,219) | (1,057,052) | |
| Forfeited | (1,036,362) | (3,528,505) | (4,445,851) | |
| Outstanding at end of period | 15,260,266 | 19,924,405 | 20,540,273 | 17,707,139 |
| Outstanding, vested and exercisable at end of period | 8,876,517 | 11,879,209 | 9,605,505 | |
| Weighted- Average Exercise Price | ||||
| Outstanding at beginning of period (in dollars per share) | $ 10.91 | $ 11.77 | $ 13.88 | |
| Granted (in dollars per share) | 5.60 | 8.78 | 10.09 | |
| Exercised (in dollars per share) | 1.13 | 0.00 | 4.34 | |
| Canceled (in dollars per share) | 14.10 | 13.41 | 17.60 | |
| Forfeited (in dollars per share) | 8.47 | 12.14 | 15.64 | |
| Outstanding at end of period (in dollars per share) | 10.23 | 10.91 | 11.77 | $ 13.88 |
| Outstanding, vested and exercisable at end of period (in dollars per share) | $ 11.63 | $ 11.73 | $ 11.89 | |
| Weighted- Average Remaining Contractual Term (in years) | ||||
| Outstanding at end of period | 7 years | 6 years 10 months 24 days | 7 years 4 months 24 days | 7 years 7 months 6 days |
| Outstanding, vested and exercisable at end of period | 6 years 1 month 6 days | 5 years 7 months 6 days | 5 years 10 months 24 days | |
| Aggregate Intrinsic Value | ||||
| Outstanding at end of period | $ 261 | $ 9,444 | $ 15,673 | $ 25,957 |
| Outstanding, vested and exercisable at end of period | $ 108 | $ 9,444 | $ 15,096 | |