v3.26.1
(Re)Insurance contracts and investment contracts with discretionary participation features - Summary of Assets and Liabilities for Groups of Insurance Contracts Issued and Reinsurance Contracts Held by Measurement Model (Detail) - EUR (€)
€ in Millions
Dec. 31, 2025
Dec. 31, 2024
Disclosure In Tabular Form Of Insurance Contracts And Reinsurance Contracts Assets And Liabilities Based On The Approach [Line Items]    
Insurance contract assets € 18 € 125
Insurance contract liabilities 176,067 188,359
Insurance contracts net balance 176,049 188,233
ReInsurance contract assets 17,153 16,021
ReInsurance contract liabilities 195 303
Reinsurance contracts net balance 16,958 15,719
Contracts not measured under the PAA [member]    
Disclosure In Tabular Form Of Insurance Contracts And Reinsurance Contracts Assets And Liabilities Based On The Approach [Line Items]    
Insurance contract assets 18 125
Insurance contract liabilities 176,024 188,318
Insurance contracts net balance 176,006 188,193
ReInsurance contract assets 17,146 16,015
ReInsurance contract liabilities 195 303
Reinsurance contracts net balance 16,950 15,712
Contracts measured under the PAA [member]    
Disclosure In Tabular Form Of Insurance Contracts And Reinsurance Contracts Assets And Liabilities Based On The Approach [Line Items]    
Insurance contract assets 0 0
Insurance contract liabilities 44 41
Insurance contracts net balance 44 41
ReInsurance contract assets 8 7
ReInsurance contract liabilities 0 0
Reinsurance contracts net balance € 8 € 7