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 | 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 | 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 | — | — | — | — | 
                                                458,857,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                417,875,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                388,816,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                314,549,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                271,214,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | — | — | 
                                                103,857,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                84,716,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                43,189,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                26,224,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                25,273,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | — | — | 
                                                522,363,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                445,843,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                378,998,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                355,371,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                319,453,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Total assets | — | — | — | 
                                                1,117,155,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1,089,053,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                725,594,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                646,873,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                610,877,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net assets per share | — | — | — | 
                                                3,275.37
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                2,773.56
                                                
                                             | — | — | 
                                                2,358.45
                                                
                                             | — | — | 
                                                2,216.19
                                                
                                             | — | — | — | 
                                                1,992.17
                                                
                                             | — | — | 
| Basic earnings (loss) per share | — | — | — | — | 
                                                783.41
                                                
                                             | — | — | — | — | — | — | — | 
                                                493.03
                                                
                                             | — | — | — | — | 
                                                258.92
                                                
                                             | 
                                                249.19
                                                
                                             | — | — | — | — | — | 
                                                181.40
                                                
                                             | — | 
| Diluted earnings per share | — | — | — | — | 
                                                781.33
                                                
                                             | — | — | — | — | — | — | — | 
                                                491.84
                                                
                                             | — | — | — | — | 
                                                258.39
                                                
                                             | 
                                                248.82
                                                
                                             | — | — | — | — | — | 
                                                181.22
                                                
                                             | — | 
| Equity-to-asset ratio | — | — | — | 
                                                0.4676
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                0.4094
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.5223
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.5494
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.5229
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Rate of return on equity | — | — | — | — | 
                                                0.2592
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                0.1917
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.1131
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.1184
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                0.0948
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | — | — | 
                                                4.34
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                6.56
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                7.95
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                7.40
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                8.46
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Number of employees | 
                                                1,107
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                3,976
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                29,775
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,562
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                371
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                3,316
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                34,198
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,215
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                5,480
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                5,399
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                5,257
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                5,574
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Average number of temporary employees | — | 
                                                279
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                394
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                15
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                100
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                437
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                491
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                551
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                562
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Revenue | — | — | — | — | — | 
                                                1,094,746,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                985,333,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                860,477,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                670,809,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                551,090,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Profit (loss) before tax | — | — | — | — | — | 
                                                115,359,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                105,975,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                71,622,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                85,199,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                33,492,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Profit (loss), attributable to owners of parent | — | — | — | — | — | 
                                                74,919,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                67,234,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                45,918,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                65,500,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                26,312,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Comprehensive income, attributable to owners of parent | — | — | — | — | — | 
                                                173,585,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                135,926,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                99,561,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                120,356,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,946,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Equity attributable to owners of parent | — | — | — | — | — | — | — | — | 
                                                893,971,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                739,565,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                614,424,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                525,312,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                415,547,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | — | — | — | — | — | — | — | 
                                                1,735,544,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,600,458,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,151,076,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                984,988,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                860,372,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Owners' equity per share | — | — | — | — | — | — | — | — | 
                                                5,605.46
                                                
                                             | — | — | 
                                                4,600.78
                                                
                                             | — | — | 
                                                3,823.47
                                                
                                             | — | — | — | — | — | 
                                                3,275.98
                                                
                                             | — | — | — | — | 
                                                2,591.44
                                                
                                             | 
| Basic earnings (loss) per share | — | — | — | — | — | 
                                                467.81
                                                
                                             | — | — | — | — | 
                                                419.32
                                                
                                             | — | — | — | — | 
                                                286.38
                                                
                                             | — | — | — | — | — | 
                                                408.47
                                                
                                             | 
                                                164.09
                                                
                                             | — | — | — | 
| Diluted earnings (loss) per share | — | — | — | — | — | 
                                                466.57
                                                
                                             | — | — | — | — | 
                                                418.31
                                                
                                             | — | — | — | — | 
                                                285.80
                                                
                                             | — | — | — | — | — | 
                                                407.86
                                                
                                             | 
                                                163.92
                                                
                                             | — | — | — | 
| Ratio of owners' equity to gross assets | — | — | — | — | — | — | — | — | 
                                                0.5151
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.4621
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.5338
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                0.5333
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.4830
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | — | — | — | 
                                                0.0917
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.0993
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.0806
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                0.1392
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.0631
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
| Price-earnings ratio | — | — | — | — | — | 
                                                7.27
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                7.71
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                7.19
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                4.51
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                9.35
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
| Cash flows from (used in) operating activities | — | — | — | — | — | 
                                                94,496,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                159,741,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                39,231,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                68,303,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                78,294,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from (used in) investing activities | — | — | — | — | — | 
                                                -1,392,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -344,015,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -46,357,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -4,479,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -27,865,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from (used in) financing activities | — | — | — | — | — | 
                                                -63,213,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                205,760,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                35,172,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -55,195,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -46,553,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash and cash equivalents | — | — | — | — | — | — | — | — | 
                                                136,215,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                97,613,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                75,572,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                42,523,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                30,760,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |