Transfers of Financial Assets - Summary of Carrying Amount of Financial Assets (Detail) - EUR (€) € in Millions |
Dec. 31, 2025 |
Dec. 31, 2024 |
|---|---|---|
| Debt securities [member] | FVOCI financial assets [member] | ||
| Disclosure of financial assets [line items] | ||
| Carrying amount of transferred assets | € 1,629 | € 1,628 |
| Carrying amount of associated liabilities | 1,677 | 1,897 |
| Debt securities [member] | FVPL financial assets [member] | ||
| Disclosure of financial assets [line items] | ||
| Carrying amount of transferred assets | 1 | 1 |
| Carrying amount of associated liabilities | 0 | 1 |
| Investments - Policyholder risk [member] | FVPL financial assets [member] | ||
| Disclosure of financial assets [line items] | ||
| Carrying amount of transferred assets | 88 | 39 |
| Carrying amount of associated liabilities | € 0 | € 0 |