Shareholdings
| Concept | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | 
|---|---|---|---|---|---|---|---|
| Shareholdings | |||||||
| Reporting company | |||||||
| Investment shares reclassified from held for purposes other than pure investment to held for pure investment | |||||||
| Issue | 
                                                三井物産㈱
                                                
                                             | 
                                                東邦亜鉛㈱
                                                
                                             | 
                                                ㈱クラレ
                                                
                                             | 
                                                住友ゴム工業㈱
                                                
                                             | 
                                                旭ダイヤモンド工業㈱
                                                
                                             | 
                                                MS&ADインシュアランスグループホールディングス㈱
                                                
                                             | 
                                                ㈱丸運
                                                
                                             | 
| Number of shares | 
                                                690
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                2,500
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                9,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                136,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                140,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                210
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                162,800
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
| Carrying amount | 
                                                1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                256,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                116,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                70,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |