v3.26.1
Financial Risks - Schedule of Credit Risk Concentration - Government Bonds (Detail) - Government bonds per country of risk [member] - Credit risk [member] - EUR (€)
€ in Millions
Dec. 31, 2025
Dec. 31, 2024
United States government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations [1] € 5,084 € 6,164
Netherlands government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations [1] 2 2
United Kingdom government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations [1] 275 334
Austria government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations [1] 9 10
Belgium government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations [1] 3 4
France government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations [1] 25 36
Hungary government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations [1] 21 25
Indonesia government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations [1] 63 69
Luxembourg government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations [1] 6 7
Spain government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations [1] 188 161
Rest of Europe government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations [1] 84 93
Rest of world government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations [1] 612 695
Government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations [1] 6,374 7,601
Americas [member] | United States government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 5,017 6,095
Americas [member] | Hungary government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 19 21
Americas [member] | Indonesia government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 63 69
Americas [member] | Rest of Europe government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 76 82
Americas [member] | Rest of world government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 586 660
Americas [member] | Government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 5,762 6,926
United Kingdom [member] | United States government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 2  
United Kingdom [member] | United Kingdom government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 257 316
United Kingdom [member] | France government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 18 28
United Kingdom [member] | Luxembourg government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 5 5
United Kingdom [member] | Rest of world government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 19 20
United Kingdom [member] | Government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 302 370
International [member] | United States government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 64 69
International [member] | Netherlands government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 2 2
International [member] | Austria government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 9 10
International [member] | Belgium government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 3 4
International [member] | France government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 8 8
International [member] | Hungary government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 2 4
International [member] | Luxembourg government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 1 1
International [member] | Spain government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 188 161
International [member] | Rest of Europe government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 8 12
International [member] | Rest of world government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 7 16
International [member] | Government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 293 286
Asset management [member] | United Kingdom government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations 17 18
Asset management [member] | Government bonds [member]    
Disclosure of credit risk exposure [line items]    
Credit risk concentrations € 17 € 18
[1] Includes investments of Holding and other activities.