Employee benefits - Additional Information (Detail) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Italian leaving indemnities (TFR) | ||
| Employee Benefits [Line Items] | ||
| Weighted average duration of defined benefit obligation | 7 years 2 months 12 days | 7 years 10 months 24 days |
| Leaving indemnities | China | ||
| Employee Benefits [Line Items] | ||
| Weighted average duration of defined benefit obligation | 8 years 6 months | 9 years 8 months 12 days |
| Leaving indemnities | Spain | ||
| Employee Benefits [Line Items] | ||
| Weighted average duration of defined benefit obligation | 7 years 4 months 24 days | 10 years 2 months 12 days |