Net Loss Per Share (Details) - shares shares in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2016 |
Jun. 30, 2015 |
Jun. 30, 2016 |
Jun. 30, 2015 |
|
| Antidilutive securities excluded from the computation of diluted net loss per share | ||||
| Antidilutive securities excluded from computation of earnings per share (in shares) | 22,679 | 20,561 | 22,588 | 20,482 |
| Employee Stock Option | ||||
| Antidilutive securities excluded from the computation of diluted net loss per share | ||||
| Antidilutive securities excluded from computation of earnings per share (in shares) | 22,232 | 20,138 | 22,232 | 20,138 |
| Warrant to purchase common stock | ||||
| Antidilutive securities excluded from the computation of diluted net loss per share | ||||
| Antidilutive securities excluded from computation of earnings per share (in shares) | 200 | 200 | 200 | 200 |
| Employee Stock Purchase Plan | ||||
| Antidilutive securities excluded from the computation of diluted net loss per share | ||||
| Antidilutive securities excluded from computation of earnings per share (in shares) | 247 | 223 | 156 | 144 |