Treasury Shares, Etc.
| Concept | 
                                    
                                        As at 2024-09-30  | 
                            
                                
                                    
                                        As at 2024-09-30  | 
                            
                        
|---|---|---|
| Treasury shares, etc. | ||
| Treasury shares, etc. | ||
| Name of shareholder | — | 
                                        
                                             
                                                株式会社北日本銀行
                                                
                                             
                                        
                                     | 
                                
                            
| Address of shareholder | — | 
                                        
                                             
                                                岩手県盛岡市中央通一丁目6番7号
                                                
                                             
                                        
                                     | 
                                
                            
| Number of shares held in own name | 
                                        
                                             
                                                332,700
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                332,700
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Number of shares held in others' names | 
                                        
                                             
                                                
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Total number of shares held | 
                                        
                                             
                                                332,700
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                332,700
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Shareholding ratio | 
                                        
                                             
                                                0.0378
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                0.0378
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     |