Employees
| Concept | As at 2024-06-30 | As at 2024-06-30 | As at 2023-06-30 | As at 2023-06-30 | As at 2022-06-30 | As at 2022-06-30 | As at 2021-06-30 | As at 2021-06-30 | As at 2020-06-30 | As at 2020-06-30 | 
|---|---|---|---|---|---|---|---|---|---|---|
| Employees | ||||||||||
| Information about reporting company | ||||||||||
| Number of employees of reporting company | ||||||||||
| Number of employees | 
                                                270
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                305
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                279
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                310
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                323
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                289
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                306
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                287
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                271
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                291
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                61
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                76
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                62
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                78
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                66
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                51
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                72
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                56
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                62
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                76
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |