Shareholdings
| Concept | 
                                    
                                        As at 2024-10-31  | 
                            
                                
                                    
                                        As at 2023-10-31  | 
                            
                        
|---|---|---|
| Shareholdings | ||
| Reporting company | ||
| Details of specified investment shares held for purposes other than pure investment | ||
| Issue | 
                                        
                                             
                                                ㈱トプコン
                                                
                                             
                                        
                                     | 
                                
                                    — | 
| Number of shares | 
                                        
                                             
                                                300,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                300,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Carrying amount | 
                                        
                                             
                                                471,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                408,450,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Purpose of shareholding, overview of business alliance, quantitative effects of shareholding and reason for increase in number of shares | 
                                        
                                             
                                                企業価値の向上を目的とし、同社との良好な取引関係の維持・発展を図るため
                                                
                                             
                                        
                                     | 
                                
                                    — | 
| Whether issuer of aforementioned shares holds reporting company's shares | 
                                        
                                             
                                                有
                                                
                                             
                                        
                                     | 
                                
                                    — |