Disclosure Of Insurance Contracts [Text Block]
| 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 | 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 | 2023-01-01 to 2023-12-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Disclosure of insurance contracts [text block] | — | — | — | — | — | — | 
                                                7.5.13
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Insurance service result [abstract] | ||||||||||||||||||||
| Insurance revenue | — | — | — | — | — | — | 
                                                9,601,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
                                                8,095,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Insurance service expenses from insurance contracts issued | — | — | — | — | — | — | 
                                                8,739,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
                                                7,628,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Income (expenses) from reinsurance contracts held, other than finance income (expenses) [abstract] | ||||||||||||||||||||
| Income (expenses) from reinsurance contracts held, other than finance income (expenses) | — | — | — | — | — | — | 
                                                90,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
                                                27,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Insurance service result | — | — | — | — | — | — | 
                                                772,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
                                                440,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Disclosure of analysis of insurance revenue [text block] | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disclosure of analysis of insurance revenue [abstract] | ||||||||||||||||||||
| Disclosure of analysis of insurance revenue [line items] | ||||||||||||||||||||
| Insurance revenue [abstract] | ||||||||||||||||||||
| Disclosure of adjustments made when entity changed basis of disaggregation of insurance finance income (expenses) between profit or loss and other comprehensive income for contracts with direct participation features [text block] | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disclosure of adjustments made when entity changed basis of disaggregation of insurance finance income (expenses) between profit or loss and other comprehensive income for contracts with direct participation features [abstract] | ||||||||||||||||||||
| Disclosure of adjustments made when entity changed basis of disaggregation of insurance finance income (expenses) between profit or loss and other comprehensive income for contracts with direct participation features [line items] | ||||||||||||||||||||
| Profit (loss) | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                946,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                946,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                2,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                944,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1,086,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1,086,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1,086,000,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             |