Net Loss per Share - Anti-dilutive Securities (Details) - shares
|
3 Months Ended |
Mar. 31, 2018 |
Mar. 31, 2017 |
| Anti-dilutive securities |
|
|
| Potential common shares excluded from computation of diluted net loss per share (in shares) |
61,245,434
|
58,667,402
|
| Options to purchase common stock |
|
|
| Anti-dilutive securities |
|
|
| Potential common shares excluded from computation of diluted net loss per share (in shares) |
15,368,789
|
13,295,581
|
| RSUs |
|
|
| Anti-dilutive securities |
|
|
| Potential common shares excluded from computation of diluted net loss per share (in shares) |
394,500
|
|
| Options to Purchase Series E-1 Preferred Stock [Member] |
|
|
| Anti-dilutive securities |
|
|
| Potential common shares excluded from computation of diluted net loss per share (in shares) |
837,835
|
837,835
|
| Common stock warrants |
|
|
| Anti-dilutive securities |
|
|
| Potential common shares excluded from computation of diluted net loss per share (in shares) |
106,250
|
106,250
|
| Redeemable convertible preferred stock warrants |
|
|
| Anti-dilutive securities |
|
|
| Potential common shares excluded from computation of diluted net loss per share (in shares) |
167,500
|
202,628
|
| Redeemable convertible preferred stock |
|
|
| Anti-dilutive securities |
|
|
| Potential common shares excluded from computation of diluted net loss per share (in shares) |
44,370,560
|
44,225,108
|