Analysis Of Income And Expense [Abstract]
| Concept | 2024-01-01 to 2024-12-31 | 2024-01-01 to 2024-12-31 | 2024-01-01 to 2024-12-31 | 2024-01-01 to 2024-12-31 | 2024-01-01 to 2024-12-31 | 2024-01-01 to 2024-12-31 | 2024-01-01 to 2024-12-31 | 2024-01-01 to 2024-12-31 | 2024-01-01 to 2024-12-31 | 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 | 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 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Analysis of income and expense [abstract] | ||||||||||||||||||
| Revenue [abstract] | ||||||||||||||||||
| Interest income | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Interest income on cash and cash equivalents | — | — | 
                                                2,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                3,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
| Material income and expense [abstract] | ||||||||||||||||||
| Expense of restructuring activities | — | — | 
                                                93,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                5,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
| Research and development expense | — | — | 
                                                86,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                68,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
| Finance income (cost) | — | — | 
                                                92,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                97,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
| Other finance income (cost) | — | — | 
                                                20,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                35,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
| Interest expense | — | — | 
                                                74,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                65,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
| Other operating income (expense) | — | — | 
                                                23,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                9,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
| Selling, general and administrative expense [abstract] | ||||||||||||||||||
| Selling, general and administrative expense | — | — | 
                                                185,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                145,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
| Expenses by nature [abstract] | ||||||||||||||||||
| Depreciation, amortisation and impairment loss (reversal of impairment loss) recognised in profit or loss [abstract] | ||||||||||||||||||
| Impairment loss (reversal of impairment loss) recognised in profit or loss | — | — | 
                                                5,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                5,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
| Miscellaneous other comprehensive income [abstract] | ||||||||||||||||||
| Income tax relating to exchange differences on translation of foreign operations and hedges of net investments in foreign operations included in other comprehensive income [abstract] | ||||||||||||||||||
| Income tax relating to exchange differences on translation of foreign operations included in other comprehensive income | — | — | 
                                                4,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                1,000,000
                                                
                                                    
                                                        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 | — | — | 
                                                1,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                25,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
| Comprehensive income, continuing and discontinued operations [abstract] | ||||||||||||||||||
| Comprehensive income | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                262,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                12,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                8,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                282,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                262,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                21,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                314,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                285,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                314,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                7,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
| Comprehensive income attributable to owners of parent, continuing and discontinued operations [abstract] | ||||||||||||||||||
| Comprehensive income, attributable to owners of parent | — | — | 
                                                262,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                314,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
| Comprehensive income attributable to non-controlling interests, continuing and discontinued operations [abstract] | ||||||||||||||||||
| Comprehensive income, attributable to non-controlling interests | — | — | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — |