Fair Value Measurement - Summary of Assets and Liabilities that Require Fair Value Measurements on a Recurring Basis (Details) - Fair Value Measurements on Recurring Basis - USD ($) $ in Thousands |
Mar. 31, 2021 |
Dec. 31, 2020 |
|---|---|---|
| Assets | ||
| Cash equivalents | $ 76,730 | $ 27,872 |
| Liabilities | ||
| Development derivative liability (Note 7) | 68,260 | 51,719 |
| Level 1 | ||
| Assets | ||
| Cash equivalents | 76,730 | 27,872 |
| Liabilities | ||
| Development derivative liability (Note 7) | 0 | 0 |
| Level 2 | ||
| Assets | ||
| Cash equivalents | 0 | 0 |
| Liabilities | ||
| Development derivative liability (Note 7) | 0 | 0 |
| Level 3 | ||
| Assets | ||
| Cash equivalents | 0 | 0 |
| Liabilities | ||
| Development derivative liability (Note 7) | $ 68,260 | $ 51,719 |