Key Financial Data Of Reporting Company
| Concept | 2024-01-01 to 2024-06-30 | As at 2024-06-30 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | 2023-01-01 to 2023-06-30 | As at 2023-06-30 | 
|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||
| Business results of reporting company | ||||||
| Net sales | 
                                                273,501,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                552,825,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                265,457,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                59,770,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                86,047,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                38,761,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                453,468,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                395,199,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                361,936,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                721,039,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                645,480,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                642,256,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Basic earnings (loss) per share | 
                                                272.81
                                                
                                             | — | 
                                                469.42
                                                
                                             | — | 
                                                189.16
                                                
                                             | — | 
| Diluted earnings per share |  | — |  | — |  | — | 
| Equity-to-asset ratio | — | 
                                                0.6289
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.6123
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.5634
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Net cash provided by (used in) operating activities | 
                                                30,920,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                86,503,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                27,499,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | 
                                                -13,236,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -14,661,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -15,410,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | 
                                                -3,277,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -62,894,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -13,249,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                71,746,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                52,798,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                42,217,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |