Notes - Segment Information, Etc.
| Concept | 
                                    
                                        2023-04-01 to 2023-12-31  | 
                            
                                
                                    
                                        2023-04-01 to 2023-12-31  | 
                            
                                
                                    
                                        2023-04-01 to 2023-12-31  | 
                            
                                
                                    
                                        2023-04-01 to 2023-12-31  | 
                            
                                
                                    
                                        2023-04-01 to 2023-12-31  | 
                            
                                
                                    
                                        2022-04-01 to 2022-12-31  | 
                            
                                
                                    
                                        2022-04-01 to 2022-12-31  | 
                            
                                
                                    
                                        2022-04-01 to 2022-12-31  | 
                            
                                
                                    
                                        2022-04-01 to 2022-12-31  | 
                            
                                
                                    
                                        2022-04-01 to 2022-12-31  | 
                            
                        
|---|---|---|---|---|---|---|---|---|---|---|
| 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 | 
                                        
                                             
                                                15,937,343,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                15,978,817,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                2,731,949,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                13,205,393,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                41,473,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                20,030,486,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                17,302,374,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                2,701,280,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                20,003,654,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                26,832,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Transactions with other segments | 
                                        
                                             
                                                6,953,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                6,953,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                6,953,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                6,840,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                6,840,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                6,840,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     |