Shareholdings
| Concept | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 
|---|---|---|---|
| Shareholdings | |||
| Reporting company | |||
| Investment shares reclassified from held for purposes other than pure investment to held for pure investment | |||
| Issue | 
                                                東邦亜鉛㈱
                                                
                                             | 
                                                三井物産㈱
                                                
                                             | 
                                                ㈱丸運
                                                
                                             | 
| Number of shares | 
                                                2,500
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                29,345
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                162,800
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
| Carrying amount | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                208,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                46,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |