Fair value measurements - Schedule of Changes in Level 3 Instruments (Details) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Fair value measurements | ||
| Balance at the beginning | $ 40,800 | $ 63,918 |
| Unrealized fair value change recognized in other comprehensive loss | $ (16,684) | $ (23,108) |
| Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Asset, Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration] | OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax | OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax |
| Foreign currency exchange losses, net | $ 14 | $ (10) |
| Balance at the end | $ 24,130 | $ 40,800 |