Basis of preparation and significant changes in the current reporting period - Additional information (Details) - EUR (€) € in Millions |
6 Months Ended | |
|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Basis of Preparation and Accounting Policies [Abstract] | ||
| Reconciliation net result effect of adjustment after tax EU IAS 39 carve-out | € (319) | € 786 |