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 group | ||||||||||
| Number of employees of group | ||||||||||
| Number of employees | 
                                                253
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                564
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                526
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                218
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                218
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                528
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                581
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                263
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                269
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                631
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                88
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                137
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                110
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                53
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                48
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                93
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                105
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                58
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                78
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                155
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |