Key Financial Data Of Group
| Concept | 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 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 | As at 2019-12-31 | 2019-01-01 to 2019-12-31 | 2019-01-01 to 2019-12-31 | As at 2019-12-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of group | ||||||||||||||||||||||
| Business results of group | ||||||||||||||||||||||
| Net sales | 
                                                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
                                                    
                                                
                                             | — | — | 
                                                62,649,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                41,068,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                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
                                                    
                                                
                                             | — | — | 
                                                4,397,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,942,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | 
                                                7,534,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                5,874,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                4,471,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,650,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,808,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Comprehensive income | 
                                                9,667,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                6,196,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                6,082,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,656,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                3,766,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net assets | — | 
                                                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
                                                    
                                                
                                             | 
                                                30,929,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                30,583,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                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
                                                    
                                                
                                             | 
                                                59,013,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                48,687,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | 
                                                3,958.89
                                                
                                             | — | — | 
                                                3,528.78
                                                
                                             | — | 
                                                3,360.83
                                                
                                             | — | 
                                                3,142.70
                                                
                                             | — | — | 
                                                2,627.07
                                                
                                             | 
                                                2,734.99
                                                
                                             | — | — | 
                                                2,377.00
                                                
                                             | — | 
                                                2,393.36
                                                
                                             | 
                                                2,169.53
                                                
                                             | — | — | 
                                                2,162.91
                                                
                                             | 
| Basic earnings (loss) per share | 
                                                542.13
                                                
                                             | — | 
                                                478.66
                                                
                                             | — | — | — | — | 
                                                415.49
                                                
                                             | — | 
                                                365.43
                                                
                                             | 
                                                277.39
                                                
                                             | — | — | 
                                                316.25
                                                
                                             | 
                                                258.17
                                                
                                             | — | 
                                                255.53
                                                
                                             | — | — | 
                                                198.59
                                                
                                             | 
                                                185.99
                                                
                                             | — | 
| Diluted earnings per share |  | — |  | — | — | — | — |  | — |  |  | — | — |  |  | — |  | — | — |  |  | — | 
| Equity-to-asset ratio | — | 
                                                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
                                                    
                                                
                                             | 
                                                0.520
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.628
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | 
                                                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
                                                    
                                                
                                             | — | — | 
                                                0.096
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.090
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | 
                                                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
                                                    
                                                
                                             | — | — | 
                                                11.38
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                12.15
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | 
                                                874,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                3,804,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                5,344,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,687,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                4,798,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | 
                                                -912,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                -752,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -671,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -779,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -1,051,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                -3,291,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                -1,291,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -1,128,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,185,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -545,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                19,654,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                22,589,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                20,527,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                16,684,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,873,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Number of employees | — | 
                                                3,830
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                2,477
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,023
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,353
                                                
                                                    
                                                        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
                                                    
                                                
                                             | 
                                                3,012
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                1,633
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | — | 
                                                1,109
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                638
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                564
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                471
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,094
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                531
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                520
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,078
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                507
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                936
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                919
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                491
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |