Net Loss Per Share - Antidilutive Securities (Details) - shares |
9 Months Ended | |
|---|---|---|
Sep. 30, 2019 |
Sep. 30, 2018 |
|
| Diluted net loss per share attributable to common stockholders | ||
| Antidilutive securities excluded from computation of of diluted weighted average shares outstanding | 16,246,836 | 17,345,706 |
| Restricted Common Stock | ||
| Diluted net loss per share attributable to common stockholders | ||
| Antidilutive securities excluded from computation of of diluted weighted average shares outstanding | 397,252 | 2,644,423 |
| Stock options | ||
| Diluted net loss per share attributable to common stockholders | ||
| Antidilutive securities excluded from computation of of diluted weighted average shares outstanding | 15,849,584 | 14,701,283 |