Employees
| Concept | 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 | 
                                                1,247
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,522
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                128
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                117
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,529
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,252
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,280
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,544
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,558
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,298
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,298
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,581
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                194
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                495
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                21
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                11
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                515
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                202
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                195
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                503
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                504
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                189
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                180
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                482
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |