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 | 
                                                12,361,247,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                22,698,846,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                11,279,894,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                2,522,935,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,991,074,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,977,126,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                27,967,029,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                26,538,803,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                25,743,111,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                35,386,083,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                34,504,281,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                33,874,055,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Basic earnings (loss) per share | 
                                                245.20
                                                
                                             | — | 
                                                278.68
                                                
                                             | — | 
                                                185.89
                                                
                                             | — | 
| Diluted earnings per share |  | — |  | — |  | — | 
| Equity-to-asset ratio | — | 
                                                0.790
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.769
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.760
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Net cash provided by (used in) operating activities | 
                                                9,379,984,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -160,001,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,695,748,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | 
                                                -476,167,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,664,683,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -595,364,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | 
                                                -1,266,552,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                169,481,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -426,623,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                9,944,757,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,293,638,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,622,357,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |