Key Financial Data Of Group
| 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 | 2024-01-01 to 2024-12-31 | 2024-01-01 to 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 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | As at 2022-12-31 | 2022-01-01 to 2022-12-31 | As at 2022-12-31 | 2022-01-01 to 2022-12-31 | 2021-01-01 to 2021-12-31 | As at 2021-12-31 | As at 2021-12-31 | 2021-01-01 to 2021-12-31 | 2020-01-01 to 2020-12-31 | As at 2020-12-31 | 2020-01-01 to 2020-12-31 | As at 2020-12-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of group | ||||||||||||||||||||||||||||
| Business results of group | ||||||||||||||||||||||||||||
| Net sales | — | — | — | — | — | 
                                                23,254,813,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,310,486,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                22,698,846,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                21,701,796,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                23,035,185,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                22,065,215,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                19,968,274,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                20,623,690,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,014,214,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                19,423,183,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | — | — | — | 
                                                3,363,586,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,423,344,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,991,074,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,887,470,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,278,316,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,068,581,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,161,183,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,107,117,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,109,198,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,124,794,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | — | — | — | — | — | — | 
                                                2,376,014,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1,989,553,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,149,288,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,083,317,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,345,532,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Comprehensive income | — | — | — | — | — | — | 
                                                2,651,428,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,184,788,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,355,351,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,273,386,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,295,696,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net assets | — | — | — | — | 
                                                27,782,819,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                28,726,109,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                26,538,803,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                25,707,150,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,675,357,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                23,894,144,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                20,009,488,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,401,908,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                17,934,063,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                18,343,091,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | — | — | — | 
                                                36,343,331,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                37,452,847,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                34,504,281,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                33,641,431,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                33,955,756,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                33,144,644,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                26,974,394,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                27,524,744,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                26,114,099,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                26,758,156,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | — | — | — | 
                                                3,891.61
                                                
                                             | — | — | — | — | — | 
                                                4,023.64
                                                
                                             | — | — | 
                                                3,717.21
                                                
                                             | — | 
                                                3,600.85
                                                
                                             | 
                                                3,456.16
                                                
                                             | — | 
                                                3,346.87
                                                
                                             | — | — | 
                                                2,802.71
                                                
                                             | 
                                                2,857.54
                                                
                                             | — | — | 
                                                2,511.94
                                                
                                             | — | 
                                                2,569.04
                                                
                                             | 
| Basic earnings (loss) per share | — | — | — | — | — | 
                                                324.42
                                                
                                             | 
                                                332.81
                                                
                                             | — | — | — | — | — | 
                                                278.68
                                                
                                             | — | 
                                                269.65
                                                
                                             | — | — | 
                                                301.05
                                                
                                             | — | 
                                                283.14
                                                
                                             | 
                                                300.55
                                                
                                             | — | — | 
                                                291.81
                                                
                                             | 
                                                188.46
                                                
                                             | — | 
                                                192.45
                                                
                                             | — | 
| Diluted earnings per share | — | — | — | — | — |  |  | — | — | — | — | — |  | — |  | — | — |  | — |  |  | — | — |  |  | — |  | — | 
| Equity-to-asset ratio | — | — | — | — | 
                                                0.764
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                0.767
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.769
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.764
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.727
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.721
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.742
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.741
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.687
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.685
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | — | — | — | 
                                                0.087
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.086
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                0.078
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.078
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.095
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.092
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.113
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.108
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.076
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.079
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | — | — | — | 
                                                7.4
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                7.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                6.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                6.5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                5.7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                6.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                6.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                6.4
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                9.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                9.1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | — | — | — | — | — | 
                                                4,005,658,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -160,001,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                4,219,957,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1,642,363,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,099,088,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) investing activities | — | — | — | — | — | — | 
                                                -1,160,667,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -1,664,683,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -2,310,277,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -1,510,799,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -674,086,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) financing activities | — | — | — | — | — | — | 
                                                -1,367,914,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                169,481,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                535,452,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -1,257,970,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,192,896,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash and cash equivalents | — | — | — | — | — | — | — | — | — | — | 
                                                3,773,561,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,293,638,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,945,246,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1,281,301,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,395,213,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Number of employees | 
                                                1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                19
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                40
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                218
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                985
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                40
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                236
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,098
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                14
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1,083
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                964
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,069
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                949
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                934
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,029
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                896
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                983
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                41
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                291
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                42
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                313
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                314
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                288
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                302
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                279
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                285
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                305
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                282
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                300
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |