Statement Of Cash Flows [Abstract]
| Concept | 2024-01-01 to 2024-12-31 | As at 2024-12-31 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | As at 2022-12-31 | 
|---|---|---|---|---|---|
| Statement of cash flows [abstract] | |||||
| Cash flows from (used in) operating activities [abstract] | |||||
| Cash flows from (used in) operations | 
                                                13,880,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                33,774,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Income taxes paid (refund), classified as operating activities | 
                                                3,204,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                5,695,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Cash flows from (used in) operating activities | 
                                                10,676,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                28,080,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Cash flows from (used in) investing activities [abstract] | |||||
| Proceeds from sales of property, plant and equipment, classified as investing activities | 
                                                212,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                20,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Purchase of property, plant and equipment, classified as investing activities | 
                                                20,716,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                13,774,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Purchase of intangible assets, classified as investing activities | 
                                                205,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                438,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Dividends received, classified as investing activities | 
                                                0
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                150,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Interest received, classified as investing activities | 
                                                741,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                263,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Other inflows (outflows) of cash, classified as investing activities | 
                                                0
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                0
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Cash flows from (used in) investing activities | 
                                                19,968,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                13,779,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Cash flows from (used in) financing activities [abstract] | |||||
| Proceeds from borrowings, classified as financing activities | 
                                                28,900,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                10,896,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Repayments of borrowings, classified as financing activities | 
                                                16,872,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                4,832,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Payments of lease liabilities, classified as financing activities | 
                                                732,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                552,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Dividends paid, classified as financing activities | 
                                                1,766,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                1,766,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Interest paid, classified as financing activities | 
                                                1,917,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                1,682,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Cash flows from (used in) financing activities | 
                                                7,613,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                2,302,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Increase (decrease) in cash and cash equivalents before effect of exchange rate changes | 
                                                1,679,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                16,602,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Effect of exchange rate changes on cash and cash equivalents [abstract] | |||||
| Effect of exchange rate changes on cash and cash equivalents | 
                                                140,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                419,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                38,416,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                39,955,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                23,772,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             |