Net Loss Per Share - Weighted Average Shares (Details) - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2019 |
Sep. 30, 2019 |
Jun. 30, 2019 |
Mar. 31, 2019 |
Dec. 31, 2018 |
Sep. 30, 2018 |
Jun. 30, 2018 |
Mar. 31, 2018 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Numerator: | |||||||||||
| Net Loss | $ (163,458) | $ (89,195) | $ (43,847) | ||||||||
| Accretion of Series A redeemable convertible preferred stock to redemption value | (656) | ||||||||||
| Net loss attributable to common stockholders | $ (44,472) | $ (47,015) | $ (39,390) | $ (32,581) | $ (27,183) | $ (26,362) | $ (21,239) | $ (14,411) | $ (163,458) | $ (89,195) | $ (44,503) |
| Denominator: | |||||||||||
| Weighted average common shares outstanding, basic and diluted | 78,688,878 | 39,285,468 | 8,023,785 | ||||||||
| Net loss per share, basic and diluted | $ (0.56) | $ (0.59) | $ (0.50) | $ (0.42) | $ (0.35) | $ (0.42) | $ (2.43) | $ (1.72) | $ (2.08) | $ (2.27) | $ (5.55) |