Statement Of Financial Position [Abstract]
| Concept | As at 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2022-12-31 | As at 2022-12-31 | As at 2022-12-31 | As at 2022-12-31 | As at 2022-12-31 | As at 2022-12-31 | As at 2022-12-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of financial position [abstract] | |||||||||||||||||||||
| Assets [abstract] | |||||||||||||||||||||
| Property, plant and equipment | — | — | — | — | — | — | 
                                                86,955,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                71,394,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Right-of-use assets | — | — | — | — | — | — | 
                                                1,140,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1,105,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Goodwill | — | — | — | — | — | — | 
                                                252,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                252,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Intangible assets other than goodwill | — | — | — | — | — | — | 
                                                1,814,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1,942,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Investments accounted for using equity method | — | — | — | — | — | — | 
                                                8,320,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                7,300,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Investments in subsidiaries, joint ventures and associates reported in separate financial statements | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Cash and cash equivalents | — | — | — | — | — | — | 
                                                38,416,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                39,955,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                23,772,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | 
| Assets | — | — | — | — | — | — | 
                                                223,535,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                197,933,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Equity and liabilities [abstract] | |||||||||||||||||||||
| Equity [abstract] | |||||||||||||||||||||
| Issued capital | — | — | — | — | — | — | 
                                                6,409,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                6,409,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Retained earnings | — | — | — | — | — | — | 
                                                94,904,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                86,589,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Share premium | — | — | — | — | — | — | 
                                                3,683,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                3,683,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Other reserves | — | — | — | — | — | — | 
                                                26,158,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                24,704,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Equity attributable to owners of parent | — | — | — | — | — | — | 
                                                131,154,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                121,386,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Equity | 
                                                94,904,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                3,683,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                6,409,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1,249,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                131,154,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                24,909,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
                                                86,589,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                24,037,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                3,683,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                6,409,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                667,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                121,385,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                23,686,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                3,500,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                73,457,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                6,369,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                502,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                106,509,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
| Liabilities [abstract] | |||||||||||||||||||||
| Trade and other payables | — | — | — | — | — | — | 
                                                31,205,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                28,435,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Current tax liabilities | — | — | — | — | — | — | 
                                                4,611,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                3,390,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Deferred tax liabilities | — | — | — | — | — | — | 
                                                725,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                982,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Liabilities | — | — | — | — | — | — | 
                                                92,381,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                76,548,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Equity and liabilities | — | — | — | — | — | — | 
                                                223,535,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                197,933,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — |