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 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 reporting company | |||||||||||||||
| Number of employees of reporting company | |||||||||||||||
| Number of employees | 
                                                1,301
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,301
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                39
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                74
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,778
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,301
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                364
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,333
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,779
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,795
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,359
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,399
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,828
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,863
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,442
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                136
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                136
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                16
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                17
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                202
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                136
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                33
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                138
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                202
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                198
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                135
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                122
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                182
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                166
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                110
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |