Employees
| Concept | 
                                    
                                        As at 2025-03-31  | 
                            
                        
|---|---|
| Employees | |
| Metrics related to human capital diversity | |
| Metrics of reporting company | |
| Ratio of female employees in managerial positions | 
                                        
                                             
                                                0.044
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Ratio of male employees taking childcare leave | |
| Calculated based on provisions of Act on Promotion of Women's Active Engagement in Professional Life | |
| Regular employees | 
                                        
                                             
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Non-regular employees | 
                                        
                                             
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Differences in wages between male and female employees | |
| All employees | 
                                        
                                             
                                                0.711
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Regular employees | 
                                        
                                             
                                                0.724
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Non-regular employees | 
                                        
                                             
                                                0.390
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     |