Shareholdings
| Concept | 
                                    
                                        As at 2025-03-31  | 
                            
                                
                                    
                                        2024-04-01 to 2025-03-31  | 
                            
                        
|---|---|---|
| Shareholdings | ||
| Reporting company | ||
| Investment shares held for purposes other than pure investment | ||
| Shares not listed | ||
| Number of issues | 
                                        
                                             
                                                21
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | 
| Carrying amount | 
                                        
                                             
                                                175,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | 
| Number of issues whose number of shares increased | — | 
                                        
                                             
                                                1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Total acquisition cost for increased shares | — | 
                                        
                                             
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Reason for increase in number of shares | — | 
                                        
                                             
                                                当社の電子部品事業譲渡に伴い、子会社株式の取り扱い区分を変更したため。
                                                
                                             
                                        
                                     | 
                                
                            
| Number of issues whose number of shares decreased | — | 
                                        
                                             
                                                2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Total sale amount for decreased shares | — | 
                                        
                                             
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Shares other than those not listed | ||
| Number of issues | 
                                        
                                             
                                                4
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | 
| Carrying amount | 
                                        
                                             
                                                2,198,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | 
| Number of issues whose number of shares increased | — | 
                                        
                                             
                                                1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Total acquisition cost for increased shares | — | 
                                        
                                             
                                                3,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Reason for increase in number of shares | — | 
                                        
                                             
                                                良好な取引関係の維持・強化を目的に加入している取引先持株会の定期買い付けのため。
                                                
                                             
                                        
                                     | 
                                
                            
| Number of issues whose number of shares decreased | — | 
                                        
                                             
                                                7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Total sale amount for decreased shares | — | 
                                        
                                             
                                                2,605,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     |