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 | 
                                                784
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                663
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                126
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4,502
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,709
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                629
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                194
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                523
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4,227
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                117
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                111
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,319
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,625
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                105
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                102
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,420
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                5,970
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,843
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                16,475
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,063
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,487
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                214
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                898
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                16,113
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                12,612
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                13,217
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                16,232
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |