Investment in associates and joint ventures - Additional information (Details) - EUR (€) € in Millions |
6 Months Ended | 12 Months Ended | |
|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Dec. 31, 2025 |
|
| Disclosure of investments in associates and joint ventures [line items] | |||
| Gross proceeds | € 458 | € 116 | |
| TMBThanachart Bank Public Company Limited | |||
| Disclosure of investments in associates and joint ventures [line items] | |||
| Percentage of ownership interest | 19.50% | ||
| Share of results | € 69 | € 136 | |
| Gross proceeds | 304 | ||
| Accumulated impairment losses | € 395 | € 395 | |
| Total for all associates | TMBThanachart Bank Public Company Limited | |||
| Disclosure of investments in associates and joint ventures [line items] | |||
| Percentage of ownership interest | 20.00% | 23.00% | |
| Associates and joint ventures | |||
| Disclosure of investments in associates and joint ventures [line items] | |||
| Share of results | € 127 | € 209 | |