v3.26.1
Capital Management and Solvency - Additional Information (Detail) - EUR (€)
€ / shares in Units, € in Millions, shares in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Disclosure of capital management and solvency [line items]    
Withdrawal of insurance license triggered by breach of Authorized Control Level (ACL), percentage 100.00%  
Percentage of higher capital requirement in SCR 50.00%  
Capital requirements on a solo-level, Solvency II ratio 100.00%  
Proportions Group Solvency Two Ratio 184.00% 188.00%
Cash capital maintained € 1,300 € 1,700
Gross Financial Leverage 4,850 5,201
Decrease in cash capital due to share buy backs 1,100  
Free Cash Flows 800  
Disposal Of Investments In Associates Joint Ventures Amount € 700  
Lower group solvency two ratio 7.00%  
Number Of Shares Sold 12.5  
Percentage Of Stake Material Associate 24.12%  
Capital Injection For Reinsurance Transaction € 800  
Decrease In Equitable Solvency Two Ratio 3.00%  
Negative Impact Recognized In Share Buy Back € 200 € 227
Increase Decrease In Solvency Ratio 4.00%  
Final Dividend [Member]    
Disclosure of capital management and solvency [line items]    
Dividends Proposed as Distributions to Owners Per Share € 0.21  
Interim Diviend [Member]    
Disclosure of capital management and solvency [line items]    
Dividends Proposed as Distributions to Owners Per Share € 0.19  
United States [member]    
Disclosure of capital management and solvency [line items]    
Risk based capital ratio 424.00% [1] 443.00%
United Kingdom [member]    
Disclosure of capital management and solvency [line items]    
Equitable solvency two ratio 183.00% [1] 186.00%
Statutory Capital Reserve For Solvency Two Units [Member]    
Disclosure of capital management and solvency [line items]    
Percentage of higher capital requirement in SCR 120.00%  
Operating level capital percentage 400.00%  
RBC Cal [Member]    
Disclosure of capital management and solvency [line items]    
Operating level capital percentage 150.00%  
Top of range [member]    
Disclosure of capital management and solvency [line items]    
Cash capital maintained € 1,500  
Bottom of range [member]    
Disclosure of capital management and solvency [line items]    
Cash capital maintained € 500  
Bottom of range [member] | United States [member]    
Disclosure of capital management and solvency [line items]    
Risk based capital ratio 400.00%  
Bottom of range [member] | United Kingdom [member]    
Disclosure of capital management and solvency [line items]    
Equitable solvency two ratio 150.00%  
[1] The capital ratios are estimates and are not final until filed with the respective supervisory authority.