Stock-based compensation - Stock Based Compensation Expense (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Stock options | |||
| Stock-based compensation expense included in total operating expenses | $ 21,136 | $ 21,522 | $ 18,409 |
| Research and development | |||
| Stock options | |||
| Stock-based compensation expense included in total operating expenses | 11,043 | 11,386 | 9,984 |
| General and administrative | |||
| Stock options | |||
| Stock-based compensation expense included in total operating expenses | 10,093 | 10,136 | 8,425 |
| Stock options | |||
| Stock options | |||
| Stock-based compensation expense included in total operating expenses | 14,171 | 15,814 | 14,528 |
| Restricted stock units and other stock awards | |||
| Stock options | |||
| Stock-based compensation expense included in total operating expenses | 6,184 | 5,175 | 3,522 |
| Employee stock purchase plan | |||
| Stock options | |||
| Stock-based compensation expense included in total operating expenses | $ 781 | $ 533 | $ 359 |