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 | 
                                                318
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                209
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                229
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                254
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                338
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                20
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                64
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                20
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                209
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                314
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                227
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                221
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                254
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                249
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                216
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                213
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                246
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                39
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                21
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                26
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                26
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                44
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                13
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                21
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                33
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                23
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                28
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                32
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                36
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                31
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                31
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                38
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |