Derivative financial instruments - Change in fair value of the derivative instruments (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
|
| Derivative financial instruments | ||||
| Change in fair value of derivative instruments | $ (25.0) | $ 40.8 | $ (37.5) | $ 45.3 |
| Embedded options within listed bonds | ||||
| Derivative financial instruments | ||||
| Change in fair value of derivative instruments | (18.5) | 30.6 | (7.1) | 34.9 |
| Foreign exchange swaps | ||||
| Derivative financial instruments | ||||
| Change in fair value of derivative instruments | $ 10.2 | $ 10.4 | ||
| Nondeliverable forwards | ||||
| Derivative financial instruments | ||||
| Change in fair value of derivative instruments | $ (6.5) | $ (30.4) | ||