Share-based compensation - Share based compensation expense (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
|
| Share-based compensation. | ||||
| Total share-based compensation expense | $ 5,418 | $ 8,771 | $ 18,752 | $ 27,811 |
| Location, Statement of Income, Balance [Axis]: us-gaap:GeneralAndAdministrativeExpense | ||||
| Share-based compensation. | ||||
| Total share-based compensation expense | 3,545 | 5,126 | 11,306 | 15,661 |
| Location, Statement of Income, Balance [Axis]: us-gaap:ResearchAndDevelopmentExpense | ||||
| Share-based compensation. | ||||
| Total share-based compensation expense | $ 1,873 | $ 3,645 | $ 7,446 | $ 12,150 |