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 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 | 
                                                1,199
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,787
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                333
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                61
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,080
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                61
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                61
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                255
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                232
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,023
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                57
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                53
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,054
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,962
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                52
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                51
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,737
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                369
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4,399
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                274
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                50
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,591
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                50
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                50
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                3,756
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,142
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,399
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                48
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                46
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,667
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,670
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                43
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                42
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                3,713
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |