Analysis Of Income And Expense [Abstract]
| Concept | 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 | 2023-01-01 to 2023-12-31 | 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 | 
|---|---|---|---|---|---|---|---|---|---|---|
| Analysis of income and expense [abstract] | ||||||||||
| Revenue [abstract] | ||||||||||
| Interest income | — | — | — | — | — | — | — | — | — | — | 
| Interest income on cash and cash equivalents | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
| Other revenue | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
| Revenue | 
                                                17,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
                                                17,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
| Material income and expense [abstract] | ||||||||||
| Profit (loss) from continuing operations attributable to non-controlling interests | 
                                                245,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
| Profit (loss) from discontinued operations attributable to non-controlling interests | 
                                                6 376
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
                                                274,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
| Other finance income | 
                                                2,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
                                                141,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
| Other finance cost | 
                                                2,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
                                                3,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
| Selling, general and administrative expense [abstract] | ||||||||||
| General and administrative expense | 
                                                16,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
                                                21,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
| Miscellaneous other comprehensive income [abstract] | ||||||||||
| Other comprehensive income, before tax, exchange differences on translation of foreign operations and hedges of net investments in foreign operations [abstract] | ||||||||||
| Other comprehensive income, before tax, exchange differences on translation of foreign operations | 
                                                583,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
                                                194,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
| Share of profit (loss) of associates and joint ventures accounted for using equity method [abstract] | ||||||||||
| Share of profit (loss) of associates and joint ventures accounted for using equity method | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
| Share of other comprehensive income of associates and joint ventures accounted for using equity method, before tax [abstract] | ||||||||||
| Share of other comprehensive income of associates and joint ventures accounted for using equity method that will be reclassified to profit or loss, before tax | 
                                                16,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
| Income tax relating to components of other comprehensive income [abstract] | ||||||||||
| Income tax relating to components of other comprehensive income that will not be reclassified to profit or loss | 
                                                5,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
                                                11,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
| Income tax relating to components of other comprehensive income that will be reclassified to profit or loss | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
| Comprehensive income, continuing and discontinued operations [abstract] | ||||||||||
| 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
                                                    
                                                
                                             | 
| Comprehensive income attributable to owners of parent, continuing and discontinued operations [abstract] | ||||||||||
| Comprehensive income, attributable to owners of parent | 
                                                1 801
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
                                                118,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
| Comprehensive income attributable to non-controlling interests, continuing and discontinued operations [abstract] | ||||||||||
| Comprehensive income, attributable to non-controlling interests | 
                                                6 223
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | 
                                                87,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — |