Employees
| Concept | As at 2024-08-31 | As at 2024-08-31 | As at 2024-08-31 | As at 2023-08-31 | As at 2023-08-31 | As at 2022-08-31 | As at 2022-08-31 | As at 2021-08-31 | As at 2021-08-31 | As at 2020-08-31 | As at 2020-08-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|
| Employees | |||||||||||
| Information about reporting company | |||||||||||
| Information about employees of reporting company | |||||||||||
| Number of employees | 
                                                388
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                388
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                342
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                328
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                377
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                410
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                363
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                354
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                301
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                312
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                267
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                275
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                275
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                84
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                644
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                819
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                6,671
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                6,492
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                7,566
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                7,446
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,595
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,510
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average age (Years) | — | — | 
                                                35.8
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
| Average length of service (Years) | — | — | 
                                                2.8
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
| Average annual salary | — | — | 
                                                6,214,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — |