Employees
| Concept | As at 2024-09-30 | As at 2024-09-30 | As at 2024-03-31 | As at 2024-03-31 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-03-31 | As at 2023-03-31 | As at 2022-09-30 | As at 2022-09-30 | 
|---|---|---|---|---|---|---|---|---|---|---|
| Employees | ||||||||||
| Information about reporting company | ||||||||||
| Information about employees of reporting company | ||||||||||
| Number of employees | 
                                                2,363
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                35
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                23
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,326
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,375
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                14
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,397
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,498
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                1,388
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                1,347
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,333
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1,333
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1,325
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — |