v3.26.1
Insurance service result - Summary of Revenue Recognized on Insurance and Investments Contracts (Detail) - EUR (€)
€ in Millions
 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Disclosure Of Detailed Information About Recognition Of Revenue In Transition To IFRS 17 [Line Items]    
Insurance revenue € 4,247 € 4,558
Insurance contracts issued [member]    
Disclosure Of Detailed Information About Recognition Of Revenue In Transition To IFRS 17 [Line Items]    
Insurance revenue 4,247 4,558 [1]
Transitioned under the modified retrospective approach [member] | Insurance contracts issued [member]    
Disclosure Of Detailed Information About Recognition Of Revenue In Transition To IFRS 17 [Line Items]    
Insurance revenue 191 234 [1]
Transitioned under the fair value approach [member] | Insurance contracts issued [member]    
Disclosure Of Detailed Information About Recognition Of Revenue In Transition To IFRS 17 [Line Items]    
Insurance revenue 3,451 3,814 [1]
Other contracts [member] | Insurance contracts issued [member]    
Disclosure Of Detailed Information About Recognition Of Revenue In Transition To IFRS 17 [Line Items]    
Insurance revenue € 605 € 510 [1]
[1] 1H 2025 figures are restated as Aegon UK is classified as discontinued operations.