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 | 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 | 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 | — | — | — | — | — | — | — | 
                                                358,668,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                328,868,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                292,333,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                264,707,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                603,213,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                523,727,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                230,975,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | — | — | — | — | — | 
                                                53,716,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                49,843,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                47,925,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                38,451,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                58,318,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                36,859,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                24,785,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                42,576,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,473,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Comprehensive income | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                53,882,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,113,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net assets | — | — | — | 
                                                352,547,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                328,610,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                301,546,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                276,851,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                326,119,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                271,459,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                304,470,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | — | — | 
                                                649,607,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                602,674,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                549,421,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                494,785,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                700,985,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                454,853,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                621,578,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | — | — | 
                                                762.73
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                711.14
                                                
                                             | — | — | 
                                                3,270.49
                                                
                                             | — | — | 
                                                3,003.62
                                                
                                             | 
                                                3,438.27
                                                
                                             | — | — | 
                                                2,838.32
                                                
                                             | — | 
                                                3,106.10
                                                
                                             | 
| Basic earnings (loss) per share | — | — | — | — | — | — | — | 
                                                100.75
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                97.09
                                                
                                             | — | — | — | — | 
                                                464.25
                                                
                                             | 
                                                378.84
                                                
                                             | — | — | 
                                                452.39
                                                
                                             | 
                                                256.85
                                                
                                             | — | 
                                                244.06
                                                
                                             | — | 
| Diluted earnings per share | — | — | — | — | — | — | — | 
                                                100.63
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                96.93
                                                
                                             | — | — | — | — | 
                                                463.17
                                                
                                             | 
                                                377.73
                                                
                                             | — | — | 
                                                451.07
                                                
                                             | 
                                                255.82
                                                
                                             | — | 
                                                243.08
                                                
                                             | — | 
| Equity-to-asset ratio | — | — | — | 
                                                0.542
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                0.545
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.548
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.558
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.451
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.595
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.477
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | — | — | — | — | — | 
                                                0.137
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                0.142
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.148
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.130
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.139
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.084
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.089
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | — | — | — | — | — | 
                                                24.4
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                17.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                10.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                16.9
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                14.1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                13.1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                13.8
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                68,549,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                64,234,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) investing activities | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                -31,754,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -29,071,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) financing activities | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                -25,179,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -9,628,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash and cash equivalents | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                136,488,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                120,544,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Number of employees | 
                                                1,384
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,505
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                904
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,109
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,824
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                10
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                1,585
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                19,126
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                3,449
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                3,896
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,213
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                7,608
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,477
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                20,510
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                3,660
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                4,688
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                4,287
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                4,103
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                18,372
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                4,047
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                17,480
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Revenue | — | — | — | — | — | — | — | — | 
                                                866,668,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                759,328,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                680,870,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                603,213,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                522,478,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Profit (loss) before tax | — | — | — | — | — | — | — | — | 
                                                99,852,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                84,733,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                69,481,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                60,302,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                35,756,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Profit (loss), attributable to owners of parent | — | — | — | — | — | — | — | — | 
                                                71,401,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                60,283,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                50,488,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                43,616,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,236,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Comprehensive income, attributable to owners of parent | — | — | — | — | — | — | — | — | 
                                                85,919,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                68,391,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                66,019,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                52,529,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                23,804,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Equity attributable to owners of parent | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                473,277,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                409,875,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                359,966,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                312,310,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                289,564,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                1,005,085,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                913,900,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                828,049,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                719,736,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                644,771,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Owners' equity per share | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                1,024.60
                                                
                                             | — | — | 
                                                887.92
                                                
                                             | — | — | 
                                                3,910.07
                                                
                                             | — | — | — | — | — | 
                                                3,395.50
                                                
                                             | — | — | — | — | 
                                                3,036.19
                                                
                                             | 
| Basic earnings (loss) per share | — | — | — | — | — | — | — | — | 
                                                154.62
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                130.73
                                                
                                             | — | — | — | — | 
                                                548.61
                                                
                                             | — | — | — | — | — | 
                                                463.44
                                                
                                             | 
                                                254.36
                                                
                                             | — | — | — | 
| Diluted earnings (loss) per share | — | — | — | — | — | — | — | — | 
                                                154.43
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                130.51
                                                
                                             | — | — | — | — | 
                                                547.34
                                                
                                             | — | — | — | — | — | 
                                                462.09
                                                
                                             | 
                                                253.34
                                                
                                             | — | — | — | 
| Ratio of owners' equity to gross assets | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                0.471
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.448
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.435
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                0.434
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.449
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | — | — | — | — | — | — | 
                                                0.162
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                0.157
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.150
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                0.145
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.086
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
| Price-earnings ratio | — | — | — | — | — | — | — | — | 
                                                15.9
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                12.8
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                8.6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                13.8
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                13.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
| Cash flows from (used in) operating activities | — | — | — | — | — | — | — | — | 
                                                100,940,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                70,012,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                37,070,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                72,858,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                68,848,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from (used in) investing activities | — | — | — | — | — | — | — | — | 
                                                -48,554,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                -35,625,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -38,324,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -31,361,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -29,200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from (used in) financing activities | — | — | — | — | — | — | — | — | 
                                                -31,915,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                -4,658,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -23,749,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -29,489,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -14,389,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash and cash equivalents | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                171,031,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                148,059,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                116,137,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                136,488,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                120,544,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |