Pension obligations (Schedule of net defined benefit liability (asset)) - (Details) - Pension obligations [Member] - USD ($) $ in Millions |
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|---|---|---|---|
| Pension Obligations [Line Items] | |||
| Present value of funded defined benefit obligation | $ 87.7 | $ 87.1 | |
| Fair value of plan assets | (94.5) | (94.2) | $ (106.0) |
| Present value of unfunded defined benefit obligation | 15.2 | 14.3 | |
| Net liability arising from defined benefit obligation | $ 8.4 | $ 7.2 |