Shareholdings
| Concept | 
                                    
                                        As at 2024-03-31  | 
                            
                                
                                    
                                        As at 2024-03-31  | 
                            
                                
                                    
                                        As at 2024-03-31  | 
                            
                                
                                    
                                        As at 2024-03-31  | 
                            
                                
                                    
                                        As at 2024-03-31  | 
                            
                                
                                    
                                        As at 2024-03-31  | 
                            
                                
                                    
                                        As at 2024-03-31  | 
                            
                                
                                    
                                        As at 2024-03-31  | 
                            
                                
                                    
                                        As at 2024-03-31  | 
                            
                                
                                    
                                        As at 2023-03-31  | 
                            
                                
                                    
                                        As at 2023-03-31  | 
                            
                                
                                    
                                        As at 2023-03-31  | 
                            
                                
                                    
                                        As at 2023-03-31  | 
                            
                                
                                    
                                        As at 2023-03-31  | 
                            
                                
                                    
                                        As at 2023-03-31  | 
                            
                                
                                    
                                        As at 2023-03-31  | 
                            
                                
                                    
                                        As at 2023-03-31  | 
                            
                                
                                    
                                        As at 2023-03-31  | 
                            
                        
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Shareholdings | ||||||||||||||||||
| Reporting company | ||||||||||||||||||
| Details of specified investment shares held for purposes other than pure investment | ||||||||||||||||||
| Issue | 
                                        
                                             
                                                三井住友建設㈱
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                三井住友トラスト・ホールディングス㈱
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                ㈱三菱UFJフィナンシャル・グループ
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                ㈱富士ピー・エス
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                佐田建設㈱
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                オリエンタル白石㈱
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                ㈱みずほフィナンシャルグループ
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                コーアツ工業㈱
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                阪和興業㈱
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | — | — | — | — | — | 
| Number of shares | 
                                        
                                             
                                                15,482
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                7,074
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                103,400
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                117,668
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                6,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                2,922
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                270
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                15,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                3,239
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                3,101
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                13,253
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                6,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                103,400
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                15,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                3,537
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                115,066
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                270
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Carrying amount | 
                                        
                                             
                                                6,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                23,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                160,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                53,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                4,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                19,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                19,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                12,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                5,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                87,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                18,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                16,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                52,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Purpose of shareholding, overview of business alliance, quantitative effects of shareholding and reason for increase in number of shares | 
                                        
                                             
                                                営業取引や情報収集等取引円滑化のため
取引先持株会による定期買付
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                金融取引や情報収集等取引円滑化のため
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                金融取引や情報収集等取引円滑化のため
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                営業取引や情報収集等取引円滑化のため
取引先持株会による定期買付
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                営業取引や情報収集等取引円滑化のため
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                営業取引や情報収集等取引円滑化のため
取引先持株会による定期買付
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                金融取引や情報収集等取引円滑化のため
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                営業取引や情報収集等取引円滑化のため
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                営業取引や情報収集等取引円滑化のため
取引先持株会による定期買付
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | — | — | — | — | — | 
| Whether issuer of aforementioned shares holds reporting company's shares | 
                                        
                                             
                                                無
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                有
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                有
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                無
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                無
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                無
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                有
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                有
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                無
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | — | — | — | — | — |