v3.26.1
Insurance Revenue - Summary of Amounts Related to Changes in Liability for Remaining Coverage (Detail) - EUR (€)
€ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of analysis of insurance revenue [line items]      
Insurance revenue € 9,097 € 9,841 € 10,386
Insurance contracts issued [member]      
Disclosure of analysis of insurance revenue [line items]      
Insurance revenue 9,020 9,761 10,322
Insurance contracts issued [member] | Insurance contracts other than those to which premium allocation approach has been applied [member]      
Disclosure of analysis of insurance revenue [line items]      
Expected insurance claims and expenses 7,194 7,870 8,383
Earnings released from CSM 930 958 952
Release of risk adjustment 265 295 340
Recovery of acquisition cash flows 538 553 558
Other (20) (19) (39)
Insurance revenue [1] 8,906 9,656 10,195
Insurance contracts issued [member] | Insurance contracts to which premium allocation approach has been applied [member]      
Disclosure of analysis of insurance revenue [line items]      
Insurance revenue 114 104 127
Insurance contracts with DPF [member]      
Disclosure of analysis of insurance revenue [line items]      
Insurance revenue 77 80 64
Insurance contracts with DPF [member] | Insurance contracts other than those to which premium allocation approach has been applied [member]      
Disclosure of analysis of insurance revenue [line items]      
Expected insurance claims and expenses 26 32 32
Earnings released from CSM 37 33 17
Release of risk adjustment 14 14 15
Recovery of acquisition cash flows 0 0 0
Other 0 0 0
Insurance revenue [1] 77 80 64
Insurance contracts with DPF [member] | Insurance contracts to which premium allocation approach has been applied [member]      
Disclosure of analysis of insurance revenue [line items]      
Insurance revenue € 0 € 0 € 0
[1] This includes contracts measured under the General model and Variable fee approach.