Disclosure Of Interests In Other Entities [Text Block]
| Concept | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | 2023-01-01 to 2023-12-31 | 2023-01-01 to 2023-12-31 | 2023-01-01 to 2023-12-31 | 2023-01-01 to 2023-12-31 | As at 2022-12-31 | 2022-01-01 to 2022-12-31 | 2022-01-01 to 2022-12-31 | 2022-01-01 to 2022-12-31 | 2022-01-01 to 2022-12-31 | 2022-01-01 to 2022-12-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Disclosure of interests in other entities [text block] | 
                                                e
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
| Disclosure of interests in subsidiaries [text block] | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disclosure of composition of group [text block] | 
                                                ______
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
| Disclosure of subsidiaries [text block] | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disclosure of subsidiaries [abstract] | ||||||||||||
| Disclosure of subsidiaries [line items] | ||||||||||||
| Profit (loss), attributable to non-controlling interests | 
                                                6 621
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                272,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
| Non-controlling interests | — | 
                                                3 202
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | 
                                                4 511
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
| Current assets | — | 
                                                18 500
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | 
                                                8 942
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
| Non-current assets | — | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | 
                                                23 485
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
| Current liabilities | — | 
                                                23 864
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | 
                                                12 708
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
| Non-current liabilities | — | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | 
                                                16 132
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
| Revenue | 
                                                17,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                17,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
| Profit (loss) | 
                                                8 564
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                6 621
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1 943
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1 943
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
                                                141,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                413,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                141,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                272,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
| Comprehensive income | 
                                                8 024
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                6 223
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1 943
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1 801
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                142,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                118,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                205,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                141,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                23,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                87,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
| Disclosure of interests in associates [text block] | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disclosure of associates [text block] | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disclosure of associates [abstract] | ||||||||||||
| Disclosure of associates [line items] | ||||||||||||
| Profit (loss) from continuing operations | 
                                                536,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                10,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
| Profit (loss) from discontinued operations | 
                                                8 028
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                423,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
| Other comprehensive income | 
                                                540,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                398,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                142,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                142,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                23,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                208,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                23,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                185,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
| Investments accounted for using equity method | — | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | 
                                                376,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
| Disclosure of interests in joint arrangements [text block] | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disclosure of joint ventures [text block] | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disclosure of joint ventures [abstract] | ||||||||||||
| Disclosure of joint ventures [line items] | ||||||||||||
| Cash and cash equivalents | — | 
                                                31,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | 
                                                2 560
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
| Tax expense (income) | 
                                                1,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                2,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — |