Shareholdings
| Concept | As at 2024-05-31 | As at 2024-05-31 | As at 2024-05-31 | As at 2024-05-31 | As at 2024-05-31 | As at 2023-05-31 | As at 2023-05-31 | As at 2023-05-31 | As at 2023-05-31 | As at 2023-05-31 | 
|---|---|---|---|---|---|---|---|---|---|---|
| Shareholdings | ||||||||||
| Reporting company | ||||||||||
| Details of specified investment shares held for purposes other than pure investment | ||||||||||
| Issue | 
                                                株式会社北國フィナンシャルホールディングス
                                                
                                             | 
                                                株式会社武蔵野銀行
                                                
                                             | 
                                                株式会社りそなホールディングス
                                                
                                             | 
                                                株式会社三井住友フィナンシャルグループ
                                                
                                             | 
                                                株式会社みずほフィナンシャルグループ
                                                
                                             | — | — | — | — | — | 
| Number of shares | 
                                                5,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                200
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                6,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                945
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                540
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                5,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                6,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                540
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                945
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                200
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
| Carrying amount | 
                                                26,100,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                656,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,504,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,724,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,735,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                23,125,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,801,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,108,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,365,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                436,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Purpose of shareholding, overview of business alliance, quantitative effects of shareholding and reason for increase in number of shares | 
                                                (目的)金融取引関係の維持・強化
(効果)(注1)
                                                
                                             | 
                                                (目的)金融取引関係の維持・強化
(効果)(注1)
                                                
                                             | 
                                                (目的)金融取引関係の維持・強化
(効果)(注1)
                                                
                                             | 
                                                (目的)金融取引関係の維持・強化
(効果)(注1)
                                                
                                             | 
                                                (目的)金融取引関係の維持・強化
(効果)(注1)
                                                
                                             | — | — | — | — | — | 
| Whether issuer of aforementioned shares holds reporting company's shares | 
                                                無
                                                
                                             | 
                                                有
                                                
                                             | 
                                                有
                                                
                                             | 
                                                有
                                                
                                             | 
                                                無
                                                
                                             | — | — | — | — | — |