Net Loss Per Share (Details) - shares shares in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2017 |
Jun. 30, 2016 |
Jun. 30, 2017 |
Jun. 30, 2016 |
|
| Antidilutive securities excluded from the computation of diluted net loss per share | ||||
| Antidilutive securities excluded from computation of earnings per share (in shares) | 22,145 | 22,679 | 22,082 | 22,588 |
| 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) | 21,958 | 22,232 | 21,958 | 22,232 |
| 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 | ||
| 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) | 187 | 247 | 124 | 156 |