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 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 | 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 | 
                                                105,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                605,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,960,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                710,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,671,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,317,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                542,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,859,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                784,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                532,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |