v3.26.1
Shareholders' Equity - Summary of Share Premium (Detail) - EUR (€)
€ in Millions
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of share premium [Line Items]      
Beginning balance € 6,853 € 6,853 € 6,853
Ending balance 6,853 6,853 6,853
Common shares [member]      
Disclosure of share premium [Line Items]      
Beginning balance 5,200 5,200  
Ending balance 5,200 5,200 5,200
Common share B [member]      
Disclosure of share premium [Line Items]      
Beginning balance 1,653 1,653  
Ending balance € 1,653 € 1,653 € 1,653