Shareholdings
| Concept | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2022-09-30 | As at 2022-09-30 | As at 2022-09-30 | As at 2022-09-30 | As at 2022-09-30 | As at 2022-09-30 | As at 2022-09-30 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Shareholdings | ||||||||||||||
| Reporting company | ||||||||||||||
| Details of specified investment shares held for purposes other than pure investment | ||||||||||||||
| Issue | 
                                                スバル興業㈱
                                                
                                             | 
                                                シンポ㈱
                                                
                                             | 
                                                スギホールディングス㈱
                                                
                                             | 
                                                ダイキン工業㈱
                                                
                                             | 
                                                大和ハウス工業㈱
                                                
                                             | 
                                                ㈱ゲオホールディングス
                                                
                                             | 
                                                ㈱十六フィナンシャルグループ
                                                
                                             | — | — | — | — | — | — | — | 
| Number of shares | 
                                                100
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                11,600
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                100
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                100
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                100
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                100
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                600
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                600
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                100
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                100
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                100
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                100
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                100
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                11,600
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
| Carrying amount | 
                                                1,213,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,360,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                594,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,347,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                401,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                237,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,247,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,463,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                581,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,229,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                294,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                177,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                892,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,029,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Whether issuer of aforementioned shares holds reporting company's shares | 
                                                無
                                                
                                             | 
                                                無
                                                
                                             | 
                                                無
                                                
                                             | 
                                                無
                                                
                                             | 
                                                無
                                                
                                             | 
                                                無
                                                
                                             | 
                                                無
                                                
                                             | — | — | — | — | — | — | — |