v3.26.1
Intangible Assets - Summary of Geographically Cash-Generating Units to Goodwill (Detail) - EUR (€)
€ in Millions
Dec. 31, 2025
Dec. 31, 2024
Disclosure of detailed information about intangible assets [Line Items]    
Goodwill € 313 € 345
Americas [member]    
Disclosure of detailed information about intangible assets [Line Items]    
Goodwill 189 215
United Kingdom [member]    
Disclosure of detailed information about intangible assets [Line Items]    
Goodwill 79 81
Asset management [member]    
Disclosure of detailed information about intangible assets [Line Items]    
Goodwill € 45 € 49