Employees
| Concept | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 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 | 
                                                352
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                887
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                313
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                38
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                38
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                69
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                780
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                872
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                349
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                347
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                809
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                760
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                352
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                403
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                807
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                87
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                155
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                81
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                28
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                122
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                171
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                98
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                90
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                161
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                168
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                92
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                114
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                196
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |