Stock-Based Compensation - Compensation expense (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2021 |
Dec. 31, 2020 |
Dec. 31, 2019 |
|
| Stock-based compensation expense | |||
| Stock-based compensation expense | $ 35,610 | $ 33,665 | $ 41,271 |
| Research and development expense | |||
| Stock-based compensation expense | |||
| Stock-based compensation expense | 12,338 | 8,023 | 9,011 |
| General and administrative expense | |||
| Stock-based compensation expense | |||
| Stock-based compensation expense | 23,272 | $ 25,642 | $ 32,260 |
| Stock options. | |||
| Stock-based compensation expense | |||
| Unrecognized compensation cost | $ 57,300 | ||
| Unrecognized compensation cost expected to be recognized over a weighted average period | 2 years 6 months | ||