Key Financial Data Of Reporting Company
| Concept | As at 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | 2024-01-01 to 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | 2022-01-01 to 2022-12-31 | As at 2022-12-31 | As at 2021-12-31 | 2021-01-01 to 2021-12-31 | 2020-01-01 to 2020-12-31 | As at 2020-12-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of reporting company | |||||||||||||||||
| Business results of reporting company | |||||||||||||||||
| Net sales | — | — | — | — | — | — | 
                                                458,857,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                417,875,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                388,816,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                314,549,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                271,214,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | — | — | — | — | 
                                                103,857,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                84,716,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                43,189,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                26,224,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                25,273,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) | — | — | — | — | — | — | 
                                                125,462,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                79,052,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                41,514,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                39,959,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                29,089,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Share capital | 
                                                38,909,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                38,909,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                38,909,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                38,909,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                38,909,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total number of issued shares | 
                                                169,549,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                169,549,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | 
                                                169,549,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                169,549,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | 
                                                169,549,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
| Net assets | 
                                                522,363,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                445,843,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                378,998,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                355,371,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                319,453,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | 
                                                1,117,155,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1,089,053,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                725,594,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                646,873,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                610,877,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | 
                                                3,275.37
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                2,773.56
                                                
                                             | — | 
                                                2,358.45
                                                
                                             | 
                                                2,216.19
                                                
                                             | — | — | 
                                                1,992.17
                                                
                                             | 
| Dividend paid per share | — | — | — | — | — | — | 
                                                98.00
                                                
                                             | — | — | 
                                                84.00
                                                
                                             | — | 
                                                66.00
                                                
                                             | — | — | 
                                                65.00
                                                
                                             | 
                                                64.00
                                                
                                             | — | 
| Interim dividend paid per share | — | — | — | — | — | — | 
                                                46.00
                                                
                                             | — | — | 
                                                34.00
                                                
                                             | — | 
                                                33.00
                                                
                                             | — | — | 
                                                32.00
                                                
                                             | 
                                                32.00
                                                
                                             | — | 
| Basic earnings (loss) per share | — | — | — | — | — | — | 
                                                783.41
                                                
                                             | — | — | 
                                                493.03
                                                
                                             | — | 
                                                258.92
                                                
                                             | — | — | 
                                                249.19
                                                
                                             | 
                                                181.40
                                                
                                             | — | 
| Diluted earnings per share | — | — | — | — | — | — | 
                                                781.33
                                                
                                             | — | — | 
                                                491.84
                                                
                                             | — | 
                                                258.39
                                                
                                             | — | — | 
                                                248.82
                                                
                                             | 
                                                181.22
                                                
                                             | — | 
| Equity-to-asset ratio | 
                                                0.4676
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                0.4094
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.5223
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.5494
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.5229
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | — | — | — | — | 
                                                0.2592
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.1917
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.1131
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.1184
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.0948
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | — | — | — | — | 
                                                4.34
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                6.56
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                7.95
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                7.40
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                8.46
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Payout ratio | — | — | — | — | — | — | 
                                                0.1251
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.1704
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.2549
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.2608
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.3528
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Number of employees | 
                                                5,562
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,107
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                29,775
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                3,316
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                34,198
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                3,976
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1,215
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                371
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                5,480
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                5,399
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,257
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                5,574
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                394
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                279
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                100
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                15
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                437
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                491
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                551
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                562
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Total shareholder return | 
                                                1.772
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1.648
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1.057
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.925
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.750
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Total return on share price index | 
                                                1.825
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1.515
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1.181
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1.211
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                1.074
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |