Deferred Expenses - Summary of Deferred Costs Arising From Insurance Contracts (Detail) - EUR (€) € in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Disclosure of deferred acquisition costs arising from insurance contracts [Line Items] | ||
| Beginning balance | € 188,359 | |
| Closing balance | 176,067 | € 188,359 |
| Deferred Transaction Costs [member] | ||
| Disclosure of deferred acquisition costs arising from insurance contracts [Line Items] | ||
| Beginning balance | 490 | 447 |
| Costs deferred during the year | 43 | 35 |
| Amortization through income statement | (23) | (22) |
| Net exchange differences | (57) | 30 |
| Closing balance | 452 | 490 |
| Current | 22 | 22 |
| Non-current | € 430 | € 468 |