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 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 | 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 | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,825,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,375,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,825,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,549,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,913,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,116,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,029,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,913,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |