Post-employment benefits - Assumptions used for defined benefit obligations (Detail) |
Dec. 31, 2025 |
Dec. 31, 2024 |
|---|---|---|
| Post-employment benefits [Line Items] | ||
| Discount rate | 4.10% | 4.00% |
| Inflation rate | 2.00% | 2.10% |
| Salary increase | 3.10% | 3.10% |
| Germany | ||
| Post-employment benefits [Line Items] | ||
| Discount rate | 3.90% | 3.30% |
| Inflation rate | 2.00% | 2.00% |
| Salary increase | 2.80% | 2.80% |
| United States | ||
| Post-employment benefits [Line Items] | ||
| Discount rate | 5.00% | 5.10% |
| Inflation rate | 2.30% | 2.30% |
| Salary increase | 0.00% | 0.00% |
| Other countries | ||
| Post-employment benefits [Line Items] | ||
| Discount rate | 4.40% | 4.20% |
| Inflation rate | 2.10% | 2.20% |
| Salary increase | 4.50% | 4.40% |