Net Loss per Share - Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | |
|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
|
| Numerator: | ||
| Net loss | $ (20,594) | $ (12,439) |
| Accretion of preferred stock to redemption value | (40,039) | (11,647) |
| Net loss attributable to common stockholders | $ (60,633) | $ (24,086) |
| Denominator: | ||
| Weighted-average common shares outstanding - basic and diluted | 11,264,252 | 10,039,592 |
| Net loss per share attributable to common stockholders - basic and diluted | $ (5.38) | $ (2.40) |