Defined contribution and defined benefit retirement plans - Summary of Actuarial Assumptions Used to Determine Net Periodic Benefit Cost (Credit) (Details) - Pension Plans |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| UNITED STATES | |||
| Pension Plans Postretirement And Other Employee Benefits [Line Items] | |||
| Discount rate | 5.50% | 5.00% | 5.30% |
| Long-term return on plan assets | 5.00% | 5.00% | 5.00% |
| Non-U.S. | |||
| Pension Plans Postretirement And Other Employee Benefits [Line Items] | |||
| Discount rate | 3.60% | 3.40% | 3.90% |
| Increase in future compensation levels | 2.80% | 2.70% | 2.70% |
| Long-term return on plan assets | 4.50% | 4.90% | 4.60% |