Nature of the Business and Basis of Presentation (Details) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
Jul. 20, 2018 |
Mar. 31, 2020 |
Mar. 31, 2019 |
Dec. 31, 2019 |
|
| Sale of Equity | ||||
| Net loss | $ (48,486) | $ (32,581) | $ 163,500 | |
| Accumulated deficit | (361,226) | $ (312,740) | ||
| Common stock | ||||
| Sale of Equity | ||||
| Conversion of redeemable convertible preferred stock to common stock (in shares) | 51,845,438 | |||
| Net loss | ||||
| IPO | ||||
| Sale of Equity | ||||
| Shares issued (in shares) | 12,055,450 | |||
| Net proceeds after deducting underwriting discounts and commissions and other offering costs | $ 254,300 | |||
| IPO | Common stock | ||||
| Sale of Equity | ||||
| Shares issued (in shares) | 12,055,450 | |||
| Overallotment | ||||
| Sale of Equity | ||||
| Shares issued (in shares) | 1,572,450 | |||