Notes - Segment Information, Etc.
| Concept | 
                                    
                                        2024-03-01 to 2024-08-31  | 
                            
                                
                                    
                                        2024-03-01 to 2024-08-31  | 
                            
                                
                                    
                                        2024-03-01 to 2024-08-31  | 
                            
                                
                                    
                                        2024-03-01 to 2024-08-31  | 
                            
                                
                                    
                                        2023-03-01 to 2023-08-31  | 
                            
                                
                                    
                                        2023-03-01 to 2023-08-31  | 
                            
                                
                                    
                                        2023-03-01 to 2023-08-31  | 
                            
                                
                                    
                                        2023-03-01 to 2023-08-31  | 
                            
                        
|---|---|---|---|---|---|---|---|---|
| Notes - Segment information, etc. | ||||||||
| Segment information | ||||||||
| Disclosure of sales, profit (loss), asset, liability, and other items for each reportable segment | ||||||||
| Sales | ||||||||
| Revenues from external customers | 
                                        
                                             
                                                10,910,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                18,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                10,928,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                10,885,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                10,905,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                19,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Transactions with other segments | 
                                        
                                             
                                                182,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                239,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                421,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                193,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                448,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                254,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     |