Key Financial Data Of Group
| Concept | 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 | 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 | — | — | 
                                                59,405,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                97,678,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                93,057,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                57,439,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                83,485,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                51,359,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                48,591,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                74,409,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                65,190,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                44,322,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | 
                                                8,932,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,535,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                10,153,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,912,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                8,235,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                7,024,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,085,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                7,118,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,216,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,019,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | — | — | — | 
                                                6,746,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                7,534,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                5,874,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                4,471,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,650,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Comprehensive income | — | — | — | 
                                                8,595,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                9,667,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                6,196,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                6,082,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,656,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net assets | 
                                                53,720,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                61,674,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                55,093,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                48,924,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                47,719,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                44,436,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                37,146,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                38,820,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                33,610,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                34,016,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | 
                                                67,383,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                87,694,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                79,914,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                62,979,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                73,296,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                58,392,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                57,510,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                71,880,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                52,628,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                63,980,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | 
                                                1,935.13
                                                
                                             | — | — | — | — | 
                                                2,213.71
                                                
                                             | — | 
                                                1,979.45
                                                
                                             | — | 
                                                1,764.39
                                                
                                             | 
                                                1,680.41
                                                
                                             | — | 
                                                1,571.35
                                                
                                             | — | — | 
                                                1,313.53
                                                
                                             | 
                                                1,367.49
                                                
                                             | — | — | 
                                                1,188.50
                                                
                                             | — | 
                                                1,196.68
                                                
                                             | 
| Basic earnings (loss) per share | — | — | 
                                                235.41
                                                
                                             | 
                                                243.10
                                                
                                             | — | — | 
                                                271.06
                                                
                                             | — | 
                                                239.33
                                                
                                             | — | — | 
                                                207.75
                                                
                                             | — | 
                                                182.71
                                                
                                             | 
                                                138.69
                                                
                                             | — | — | 
                                                158.13
                                                
                                             | 
                                                129.08
                                                
                                             | — | 
                                                127.77
                                                
                                             | — | 
| Diluted earnings per share | — | — |  |  | — | — |  | — |  | — | — |  | — |  |  | — | — |  |  | — |  | — | 
| Equity-to-asset ratio | 
                                                0.797
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.701
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.687
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.777
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.648
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.761
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.646
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.538
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.639
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.529
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | 
                                                0.127
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.116
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.147
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.143
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.131
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.122
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.111
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.123
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.113
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.113
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | 
                                                5.22
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5.06
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                9.70
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                10.99
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                7.73
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                8.78
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                9.01
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                7.90
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                9.22
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                9.32
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | — | — | 
                                                2,410,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                874,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                3,804,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                5,344,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,687,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) investing activities | — | — | — | 
                                                -4,805,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -912,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -752,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -671,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -779,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) financing activities | — | — | — | 
                                                -2,111,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -3,291,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -1,291,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -1,128,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,185,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash and cash equivalents | — | — | — | — | — | 
                                                15,523,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                19,654,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                22,589,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                20,527,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                16,684,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Number of employees | 
                                                2,151
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,674
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                1,292
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                3,966
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                3,830
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                2,023
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                3,716
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1,912
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                1,815
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                3,359
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                1,729
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                3,088
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                588
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                665
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                441
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,106
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1,109
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                564
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,094
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                531
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                520
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,078
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                507
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                936
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |