Employees
| 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 2024-12-31 | As at 2024-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2022-12-31 | As at 2022-12-31 | As at 2021-12-31 | As at 2021-12-31 | As at 2020-12-31 | As at 2020-12-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Employees | |||||||||||||||||
| Information about group | |||||||||||||||||
| Number of employees of group | |||||||||||||||||
| Number of employees | 
                                                604
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                183
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,756
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                9,166
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,391
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                35,338
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                33,947
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                183
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                21,421
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                34,388
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                151
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                33,482
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                147
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                137
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                33,226
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                33,151
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                111
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                98
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                25
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                422
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,345
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                462
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,072
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4,610
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                25
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,745
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,160
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                23
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,386
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                18
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                18
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4,984
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,069
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                17
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |