Derivative financial instruments - Change in fair value of the derivative instruments (Details) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
|
| Derivative financial instruments | ||
| Change in fair value of derivative instruments | $ (19.2) | $ 3.0 |
| Embedded options within listed bonds | ||
| Derivative financial instruments | ||
| Change in fair value of derivative instruments | (6.2) | 2.9 |
| Foreign exchange swaps | ||
| Derivative financial instruments | ||
| Change in fair value of derivative instruments | $ 0.1 | |
| Nondeliverable forwards | ||
| Derivative financial instruments | ||
| Change in fair value of derivative instruments | $ (13.0) | |