Income taxes - Movement of the valuation allowance for the deferred tax assets (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Deferred Tax Assets [Roll Forward] | |||
| Beginning balance | $ 102,576 | $ 81,830 | $ 77,874 |
| Increase during the year | 10,915 | 23,648 | 6,418 |
| Foreign currency translation adjustments | 5,581 | (2,902) | (2,462) |
| Ending balance | $ 119,072 | $ 102,576 | $ 81,830 |