Equity - Share of equity method investments additional information (Details) - EUR (€) € in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Disclosure of equity [Line Items] | |||
| Share of associates, joint venture and other reserves including non-distributable profits from associates and joint ventures | € 962 | € 940 | € 815 |
| Legal and statutory reserves | |||
| Disclosure of equity [Line Items] | |||
| Unrealised revaluations | (802) | (830) | (998) |
| Share of associates, joint ventures and other reserves | |||
| Disclosure of equity [Line Items] | |||
| Transfer to/from retained earnings | (590) | (565) | (892) |
| Software and other intangible assets | |||
| Disclosure of equity [Line Items] | |||
| Legal reserve | 956 | 768 | 628 |
| Stichting Regio Bank and Stichting Vakbondsspaarbank SPN | |||
| Disclosure of equity [Line Items] | |||
| Statutory reserve | € 108 | € 897 | € 1,602 |