Employee benefits - Defined contribution plans (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
|
| Austria | ||||
| Defined Contribution Plan Disclosure [Line Items] | ||||
| Defined contribution plan, cost incurred | $ 10.3 | $ 8.8 | $ 33.8 | $ 28.7 |
| United States | ||||
| Defined Contribution Plan Disclosure [Line Items] | ||||
| Defined contribution plan, cost incurred | $ 0.9 | $ 0.6 | $ 5.2 | $ 3.9 |