Financial instruments - (Schedule of share price risk) (Details) - Share price risk [Member] - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Disclosure of detailed information about financial instruments [line items] | ||
| Sensitivity analysis, variance, percentage | 25.00% | 25.00% |
| Effect of variance increase on after-tax profit | $ 32.0 | $ 3.0 |
| Effect of variance decrease on after-tax profit | $ (32.0) | $ (3.0) |