Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept | As at 2024-12-31 | As at 2023-12-31 | As at 2022-12-31 | As at 2021-12-31 | 
|---|---|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | ||||
| Intangible assets and goodwill [abstract] | ||||
| Intangible assets other than goodwill [abstract] | ||||
| Intangible assets other than goodwill | 
                                                2,982,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                3,190,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Goodwill | 
                                                10,383,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                9,876,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Investments accounted for using equity method [abstract] | ||||
| Investments in associates accounted for using equity method | 
                                                257,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                381,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Trade and other non-current receivables [abstract] | ||||
| Trade and other non-current receivables | 
                                                208,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                193,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Miscellaneous non-current assets [abstract] | ||||
| Non-current derivative financial assets | 
                                                8,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                3,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Trade and other current receivables [abstract] | ||||
| Trade and other current receivables | 
                                                3,672,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                3,733,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Current prepayments and current accrued income including current contract assets [abstract] | ||||
| Current prepayments and current accrued income including current contract assets | 
                                                586,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                500,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Classes of current inventories [abstract] | ||||
| Current inventories | 
                                                3,198,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                3,491,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Classes of current inventories, alternative [abstract] | ||||
| Cash and cash equivalents [abstract] | ||||
| Cash and cash equivalents | 
                                                2,401,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1,869,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1,172,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                2,303,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
| Non-current assets or disposal groups classified as held for sale or as held for distribution to owners [abstract] | ||||
| Non-current assets or disposal groups classified as held for sale or as held for distribution to owners | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                79,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Miscellaneous current assets [abstract] | ||||
| Current derivative financial assets | 
                                                69,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                45,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Borrowings [abstract] | ||||
| Non-current portion of non-current borrowings | 
                                                7,113,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                7,035,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Current borrowings and current portion of non-current borrowings [abstract] | ||||
| Current borrowings and current portion of non-current borrowings | 
                                                526,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                654,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Non-current portion of non-current borrowings, by type [abstract] | ||||
| Current borrowings and current portion of non-current borrowings, by type [abstract] | ||||
| Trade and other non-current payables [abstract] | ||||
| Non-current accruals and non-current deferred income including non-current contract liabilities [abstract] | ||||
| Non-current deferred income including non-current contract liabilities [abstract] | ||||
| Non-current contract liabilities [abstract] | ||||
| Non-current contract liabilities | 
                                                431,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                469,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Trade and other current payables [abstract] | ||||
| Current accruals and current deferred income including current contract liabilities [abstract] | ||||
| Current deferred income including current contract liabilities [abstract] | ||||
| Current contract liabilities [abstract] | ||||
| Current contract liabilities | 
                                                1,699,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1,809,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Accruals classified as current | 
                                                1,630,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1,887,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Trade and other current payables | 
                                                1,830,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1,917,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Miscellaneous non-current liabilities [abstract] | ||||
| Non-current derivative financial liabilities | 
                                                4,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                3,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Miscellaneous current liabilities [abstract] | ||||
| Current derivative financial liabilities | 
                                                59,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                40,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Current dividend payables | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                11,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Issued capital [abstract] | ||||
| Issued capital | 
                                                188,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                183,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Net assets (liabilities) [abstract] | ||||
| Assets | 
                                                28,976,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                29,406,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Liabilities | 
                                                16,933,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                17,345,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Net current assets (liabilities) [abstract] | ||||
| Current assets | 
                                                10,022,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                9,940,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Current liabilities | 
                                                8,146,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                8,287,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Assets less current liabilities [abstract] |