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 | 
                                                15,760,672,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                20,604,232,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                14,986,576,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                1,546,317,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,948,094,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,355,897,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                17,189,015,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                15,870,650,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                15,491,372,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Total assets | — | 
                                                24,051,844,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                20,908,738,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                20,748,550,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Basic earnings (loss) per share | 
                                                171.31
                                                
                                             | — | 
                                                54.04
                                                
                                             | — | 
                                                177.14
                                                
                                             | — | 
                                                123.19
                                                
                                             | 
                                                47.58
                                                
                                             | 
| Diluted earnings per share | 
                                                169.85
                                                
                                             | — | — | — | 
                                                175.30
                                                
                                             | — | 
                                                121.91
                                                
                                             | — | 
| Equity-to-asset ratio | — | 
                                                0.701
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.744
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.731
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — |