Disclosure Of Entity's Operating Segments [Text Block]
| Concept | 2024-01-01 to 2024-12-31 | As at 2024-12-31 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | 2022-01-01 to 2022-12-31 | 
|---|---|---|---|---|---|
| Disclosure of entity's operating segments [text block] | — | — | — | — | — | 
| Disclosure of operating segments [text block] | — | — | — | — | — | 
| Disclosure of operating segments [abstract] | |||||
| Disclosure of operating segments [line items] | |||||
| Revenue | 
                                                18,021,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                18,169,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                17,827,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
| Tax expense (income) | 
                                                963,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                73,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                113,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
| Profit (loss) before tax | 
                                                123,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                526,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                1,731,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
| Profit (loss) from continuing operations | 
                                                840,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                454,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                1,618,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
| Profit (loss) | 
                                                698,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                463,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                1,605,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
| Assets | — | 
                                                28,976,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                29,406,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Liabilities | — | 
                                                16,933,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                17,345,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Disclosure of products and services [text block] | — | — | — | — | — | 
| Disclosure of products and services [abstract] | |||||
| Disclosure of products and services [line items] | |||||
| Disclosure of geographical areas [text block] | — | — | — | — | — | 
| Disclosure of geographical areas [abstract] | |||||
| Disclosure of geographical areas [line items] | |||||
| Disclosure of major customers [text block] | — | — | — | — | — | 
| Disclosure of major customers [abstract] | |||||
| Disclosure of major customers [line items] |