Notes - Segment Information, Etc.
| Concept | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 
|---|---|---|---|---|---|---|---|---|---|---|
| Notes - Segment information, etc. | ||||||||||
| Amortization and unamortized balance of goodwill for each reportable segment | ||||||||||
| Amortization and unamortized balance of goodwill for each reportable segment | ||||||||||
| Goodwill | 
                                                715,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                715,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                715,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,528,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,819,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,528,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                708,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |