Investment and return - Narrative (Details) - EUR (€) € in Millions |
Dec. 31, 2025 |
Dec. 31, 2024 |
|---|---|---|
| Investment And Return [Abstract] | ||
| Cash and cash equivalents held by central finance companies | € 600 | |
| Percentage of cash and cash equivalents held by central finance companies | 15.00% | |
| Cash and cash equivalents held with foreign subsidiaries | € 3,300 | |
| Percentage of cash and cash equivalents held with foreign subsidiaries | 85.00% | |
| Cash and cash equivalents held by entity unavailable for use by group | € 160 | € 176 |
| Collateral held permitted to be sold or repledged in absence of default by owner of collateral, at fair value | € 28 | € 89 |