Disclosure Of Fair Value Measurement [Text Block]
| Concept | As at 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | 2024-01-01 to 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2022-12-31 | As at 2022-12-31 | As at 2022-12-31 | As at 2022-12-31 | As at 2022-12-31 | As at 2022-12-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Disclosure of fair value measurement [text block] | — | — | — | — |  | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disclosure of fair value measurement of assets [text block] | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disclosure of fair value measurement of assets [abstract] | |||||||||||||||||||
| Disclosure of fair value measurement of assets [line items] | |||||||||||||||||||
| Assets | — | — | — | — | — | 
                                                1,434,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
                                                1,410,900
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Reconciliation of changes in fair value measurement, assets [abstract] | |||||||||||||||||||
| Disclosure of fair value measurement of liabilities [text block] | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disclosure of fair value measurement of liabilities [abstract] | |||||||||||||||||||
| Disclosure of fair value measurement of liabilities [line items] | |||||||||||||||||||
| Liabilities | — | — | — | — | — | 
                                                9,033,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
                                                9,120,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Reconciliation of changes in fair value measurement, liabilities [abstract] | |||||||||||||||||||
| Disclosure of fair value measurement of equity [text block] | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disclosure of fair value measurement of equity [abstract] | |||||||||||||||||||
| Disclosure of fair value measurement of equity [line items] | |||||||||||||||||||
| Equity | 
                                                2,745,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                2,198,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                396,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                53,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                5,307,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                85,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                115,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                4,989,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                2,498,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                2,198,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                11,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                396,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                3,711,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                95,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                2,198,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1,232,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                396,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                20,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
| Reconciliation of changes in fair value measurement, entity's own equity instruments [abstract] |