Employees
| Concept | As at 2024-03-31 | As at 2024-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2022-03-31 | As at 2022-03-31 | As at 2021-03-31 | As at 2021-03-31 | As at 2020-03-31 | As at 2020-03-31 | 
|---|---|---|---|---|---|---|---|---|---|---|
| Employees | ||||||||||
| Information about reporting company | ||||||||||
| Number of employees of reporting company | ||||||||||
| Number of employees | 
                                                755
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,263
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,254
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                752
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                747
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,249
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,209
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                750
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                738
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,227
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |