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 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 | 
                                                289
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                54
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                244
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                274
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                54
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                165
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,096
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,325
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                609
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                244
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,589
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,521
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,277
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,833
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,866
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,536
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,592
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,906
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,639
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,910
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,676
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,946
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                37
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                8
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                45
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                111
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                8
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                26
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                217
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                281
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                216
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                45
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                362
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                587
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                542
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                407
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                388
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                558
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                575
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                368
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                557
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                361
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                616
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                384
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |