v3.26.1
Dividends paid and proposed - Schedule of Dividends Proposed (Detail) - EUR (€)
€ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Disclosure Of Dividends Proposed [Line Items]    
Dividends proposed € 112 € 112
Class A Shares [Member]    
Disclosure Of Dividends Proposed [Line Items]    
Dividends proposed 93 93
Class B Shares [Member]    
Disclosure Of Dividends Proposed [Line Items]    
Dividends proposed € 19 € 19