Derivative financial instruments - Reconciliation of movements (Details) - Foreign exchange swaps/nondeliverable forwards - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
|
| Derivative financial instruments | ||
| Opening balance | $ (1,393) | $ (3,771) |
| Fair value loss (unrealized foreign exchange on open contracts) | (92,151) | (1,599) |
| Foreign exchange gain | 25,831 | 780 |
| Cash flow on settlement | (420) | 3,197 |
| Ending balance | $ (68,133) | $ (1,393) |