Employees
| Concept | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | 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 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Employees | ||||||||||||||||||
| Information about group | ||||||||||||||||||
| Number of employees of group | ||||||||||||||||||
| Number of employees | 
                                                249
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                45
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                672
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                30
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                679
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                724
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                256
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                286
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                291
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                729
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                733
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                297
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                302
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                748
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                770
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                305
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                11
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                615
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                615
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                620
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                11
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                13
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                15
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                600
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                628
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                16
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                22
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                681
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                711
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                27
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |