Stock-Based Compensation - Compensation expense (Details) - USD ($)
$ in Thousands |
1 Months Ended |
12 Months Ended |
|
Oct. 31, 2018 |
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Apr. 30, 2017 |
| Stock-based compensation expense |
|
|
|
|
|
| Stock-based compensation expense |
|
$ 33,665
|
$ 41,271
|
$ 27,528
|
|
| Research and development expenses |
|
|
|
|
|
| Stock-based compensation expense |
|
|
|
|
|
| Stock-based compensation expense |
|
8,023
|
9,011
|
3,787
|
|
| General and administrative expenses |
|
|
|
|
|
| Stock-based compensation expense |
|
|
|
|
|
| Stock-based compensation expense |
|
25,642
|
$ 32,260
|
23,741
|
|
| Stock options. |
|
|
|
|
|
| Stock-based compensation expense |
|
|
|
|
|
| Stock-based compensation expense |
|
|
|
$ 2,200
|
|
| Unrecognized compensation cost |
|
$ 43,200
|
|
|
|
| Purchase of an aggregate shares of common stock |
|
4,289,471
|
|
|
|
| Unrecognized compensation cost expected to be recognized over a weighted average period |
|
1 year 9 months 18 days
|
|
|
|
| Options for the purchase of shares of common stock cancelled |
|
|
257,854
|
|
|
| Performance-based vesting |
|
|
|
|
|
| Stock-based compensation expense |
|
|
|
|
|
| Stock-based compensation expense |
|
$ 1,100
|
|
|
|
| Purchase of an aggregate shares of common stock |
|
|
|
447,000
|
|
| Shares issued |
|
0
|
|
|
|
| Unvested restricted common stock |
|
|
|
|
|
| Stock-based compensation expense |
|
|
|
|
|
| Stock-based compensation expense |
|
$ 100
|
$ 7,600
|
$ 7,300
|
|
| Shares issued |
|
|
99,314
|
|
|
| Market-Based Stock Options |
|
|
|
|
|
| Stock-based compensation expense |
|
|
|
|
|
| Purchase of an aggregate shares of common stock |
|
0
|
0
|
|
|
| Market based and service based vesting |
|
|
|
|
|
| Stock-based compensation expense |
|
|
|
|
|
| Stock-based compensation expense |
|
$ 600
|
$ 900
|
$ 200
|
|
| Market based and service based vesting | Executive officer |
|
|
|
|
|
| Stock-based compensation expense |
|
|
|
|
|
| Purchase of an aggregate shares of common stock |
164,400
|
|
|
|
|
| Executive officer |
|
|
|
|
|
| Stock-based compensation expense |
|
|
|
|
|
| Purchase of an aggregate shares of common stock |
193,400
|
|
|
|
|
| Executive officer | Unvested restricted common stock |
|
|
|
|
|
| Stock-based compensation expense |
|
|
|
|
|
| Shares issued |
|
|
|
|
460,000
|