Key Financial Data Of Reporting Company
| Concept | 2023-04-01 to 2023-12-31 | As at 2023-12-31 | 2023-10-01 to 2023-12-31 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | As at 2022-12-31 | 2022-04-01 to 2022-12-31 | 2022-10-01 to 2022-12-31 | 
|---|---|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||||
| Business results of reporting company | ||||||||
| Net sales | 
                                                27,321,260,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                35,507,623,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                27,037,201,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                1,624,282,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,500,560,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,492,036,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                14,401,931,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                13,476,971,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                13,481,044,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Total assets | — | 
                                                28,428,235,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                27,690,271,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                29,483,278,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Basic earnings (loss) per share | 
                                                730.10
                                                
                                             | — | 
                                                650.41
                                                
                                             | — | 
                                                676.32
                                                
                                             | — | 
                                                666.70
                                                
                                             | 
                                                480.15
                                                
                                             | 
| Diluted earnings per share |  | — | — | — |  | — |  | — | 
| Equity-to-asset ratio | — | 
                                                0.501
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.482
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.452
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — |