Earnings per share - Schedule of Weighted Average Number of Shares used in Calculating Basic Earnings Per Share Value (Parenthetical) (Detail) - Class B Shares [Member] - EUR (€) € in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Disclosure of weighted average number of shares used in calculating basic earnings per share value [line items] | |||
| Weighted average number of share held value | € 173.8 | € 182.3 | € 185.7 |
| Percentage of own share held on relative economic right | 40.00% | ||