Employees
| Concept | As at 2024-03-31 | As at 2024-03-31 | 
|---|---|---|
| Employees | ||
| Metrics related to human capital diversity | ||
| Metrics of consolidated subsidiaries | ||
| Consolidated subsidiaries | 
                                                株式会社肥後銀行
                                                
                                             | 
                                                株式会社鹿児島銀行
                                                
                                             | 
| Ratio of female employees in managerial positions | 
                                                0.149
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.105
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Ratio of male employees taking childcare leave | ||
| All employees | 
                                                1.074
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1.164
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Differences in wages between male and female employees | ||
| All employees | 
                                                0.499
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.460
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Regular employees | 
                                                0.616
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.552
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Non-regular employees | 
                                                0.451
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.483
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |