Earnings per share - Schedule of Weighted Average Number of Shares used in Calculating Diluted Earnings Per Share Value (Detail) - 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 diluted earnings per share value [line items]

Weighted average number of shares used in calculating diluted earnings per share value

€ 413.7

€ 429.1

€ 439.1

Class A Shares [Member]

Disclosure of weighted average number of shares used in calculating diluted earnings per share value [line items]

Weighted average number of shares used in calculating diluted earnings per share value

344.2

356.2

364.8

Class B Shares [Member]

Disclosure of weighted average number of shares used in calculating diluted earnings per share value [line items]

Weighted average number of shares used in calculating diluted earnings per share value

^[1]

€ 69.5

€ 72.9

€ 74.3

[1]	Weighted average number of Class B shares of 173.8 million (2024: 182.3 million, 2023: 185.7 million), net of own shares held, was multiplied by 40% considering the relative economic rights.