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] | |||||
| Income taxes paid (refund), classified as operating activities | 
                                                96,612,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                20,627,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Cash flows from (used in) operating activities | 
                                                168,514,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                126,559,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Cash flows from (used in) investing activities [abstract] | |||||
| Proceeds from sales of property, plant and equipment, classified as investing activities | 
                                                305,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                3,533,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Purchase of property, plant and equipment, classified as investing activities | 
                                                1,988,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                2,351,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Interest received, classified as investing activities | 
                                                9,827,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                6,683,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Cash flows from (used in) investing activities | 
                                                34,208,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                154,574,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Cash flows from (used in) financing activities [abstract] | |||||
| Payments from changes in ownership interests in subsidiaries that do not result in loss of control | 
                                                532,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                28,800,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Payments of other equity instruments | 
                                                3,869,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Payments of lease liabilities, classified as financing activities | 
                                                4,397,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                8,232,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Interest paid, classified as financing activities | 
                                                146,711,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                119,619,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Cash flows from (used in) financing activities | 
                                                30,096,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                205,524,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                246,990,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
                                                377,419,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                386,985,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             |