Other Assets and Receivables - Summary of Real Estate Held for Own Use and Equipment (Detail) - EUR (€) € in Millions |
Dec. 31, 2025 |
Dec. 31, 2024 |
|---|---|---|
| Disclosure of other assets and receivables [Line Items] | ||
| Real estate held for own use and equipment | € 200 | € 236 |
| Real estate held for own use [member] | ||
| Disclosure of other assets and receivables [Line Items] | ||
| Real estate held for own use and equipment | 56 | 66 |
| Equipment [member] | ||
| Disclosure of other assets and receivables [Line Items] | ||
| Real estate held for own use and equipment | € 144 | € 170 |