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 | 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] | ||||||||
| Revenue | — | 
                                                2,693,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
                                                3,382,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Material income and expense [abstract] | ||||||||
| Finance income (cost) | — | 
                                                41,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
                                                23,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Expenses by nature [abstract] | ||||||||
| Classes of employee benefits expense [abstract] | ||||||||
| Employee benefits expense | — | 
                                                1,150,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
                                                1,107,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Depreciation, amortisation and impairment loss (reversal of impairment loss) recognised in profit or loss [abstract] | ||||||||
| Depreciation and amortisation expense [abstract] | ||||||||
| Depreciation and amortisation expense | — | 
                                                899,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
                                                867,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Impairment loss (reversal of impairment loss) recognised in profit or loss | — | 
                                                0
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
                                                23,766,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Other expenses, by nature | — | 
                                                713,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | 
                                                1,533,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Disclosure of attribution of expenses by nature to their function [text block] | — | — | — | — | — | — | — | — | 
| Disclosure of attribution of expenses by nature to their function [abstract] | ||||||||
| Disclosure of attribution of expenses by nature to their function [line items] | ||||||||
| Comprehensive income attributable to owners of parent, continuing and discontinued operations [abstract] | ||||||||
| Comprehensive income, attributable to owners of parent | 
                                                0
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1,369,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1,369,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                26,817,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                26,817,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             |