Disclosure Of Entity's Operating Segments [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 | 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 | 
|---|---|---|---|---|---|---|---|---|---|---|
| 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 | 
                                                17,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                17,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Share of profit (loss) of associates and joint ventures accounted for using equity method | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                2,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Tax expense (income) | 
                                                1,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                2,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Profit (loss) from continuing operations | 
                                                536,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                10,000,000
                                                
                                                    
                                                        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
                                                    
                                                
                                             | 
| Assets | — | 
                                                18 500
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
                                                32 427
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | 
| Investments accounted for using equity method | — | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
                                                376,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | 
| Cash flows from (used in) operating activities | 
                                                660,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                1 166
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Cash flows from (used in) investing activities | 
                                                144,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                111,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Cash flows from (used in) financing activities | 
                                                165,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                1 315
                                                
                                                    
                                                        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] |