Analysis Of Income And Expense [Abstract]
| Concept | 2024-01-01 to 2024-12-31 | 2023-01-01 to 2023-12-31 | 
|---|---|---|
| Analysis of income and expense [abstract] | ||
| Revenue [abstract] | ||
| Revenue | 
                                                4,698,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                4,535,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
| Expenses by nature [abstract] | ||
| Classes of employee benefits expense [abstract] | ||
| Employee benefits expense | 
                                                484,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                528,000
                                                
                                                    
                                                        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 | 
                                                0
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
| Income tax relating to components of other comprehensive income [abstract] | ||
| Income tax relating to components of other comprehensive income | 
                                                0
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
| Comprehensive income, continuing and discontinued operations [abstract] | ||
| Comprehensive income | 
                                                487,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                3,501,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
| Comprehensive income attributable to owners of parent, continuing and discontinued operations [abstract] | ||
| Comprehensive income, attributable to owners of parent | 
                                                497,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                3,471,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
| Comprehensive income attributable to non-controlling interests, continuing and discontinued operations [abstract] | ||
| Comprehensive income, attributable to non-controlling interests | 
                                                10,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                30,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             |