Key Financial Data Of Reporting Company
| Concept | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | 2023-10-01 to 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2023-09-30 | 2022-10-01 to 2023-09-30 | As at 2023-09-30 | 2021-10-01 to 2022-09-30 | As at 2022-09-30 | As at 2022-09-30 | As at 2021-09-30 | 2020-10-01 to 2021-09-30 | As at 2021-09-30 | 2019-10-01 to 2020-09-30 | As at 2020-09-30 | As at 2020-09-30 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of reporting company | |||||||||||||||||||||
| Business results of reporting company | |||||||||||||||||||||
| Net sales | — | — | — | — | — | 
                                                23,487,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                22,904,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                22,731,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                23,106,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                23,896,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Ordinary profit (loss) | — | — | — | — | — | 
                                                2,368,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,628,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -130,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,508,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,495,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Profit (loss) | — | — | — | — | — | 
                                                1,566,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,526,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -378,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -9,790,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,538,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Share capital | — | — | — | — | — | — | 
                                                9,716,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                9,716,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                9,716,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                9,716,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                9,716,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total number of issued shares | — | — | — | — | — | — | 
                                                134,239
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | 
                                                134,239
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | 
                                                134,239
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | 
                                                134,239
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | 
                                                134,239
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | 
| Net assets | — | — | — | — | — | — | 
                                                25,324,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                24,348,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                24,131,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                24,910,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                35,357,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | — | — | — | — | — | — | 
                                                32,301,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                33,326,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                34,644,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                34,122,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                48,729,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets per share | — | — | — | — | — | — | 
                                                197.45
                                                
                                             | — | — | 
                                                189.47
                                                
                                             | — | — | — | 
                                                182.46
                                                
                                             | — | 
                                                188.75
                                                
                                             | — | — | — | 
                                                268.30
                                                
                                             | — | 
| Dividend paid per share | — | — | — | — | — | 
                                                0.73
                                                
                                             | — | — | — | — | 
                                                4.26
                                                
                                             | — | 
                                                2.25
                                                
                                             | — | — | — | 
                                                3.62
                                                
                                             | — | 
                                                5.29
                                                
                                             | — | — | 
| Interim dividend paid per share | — | — | — | — | — |  | — | — | — | — |  | — |  | — | — | — |  | — |  | — | — | 
| Basic earnings (loss) per share | — | — | — | — | — | 
                                                12.24
                                                
                                             | — | — | — | — | 
                                                11.88
                                                
                                             | — | 
                                                -2.87
                                                
                                             | — | — | — | 
                                                -74.30
                                                
                                             | — | 
                                                19.01
                                                
                                             | — | — | 
| Diluted earnings per share | — | — | — | — | — | 
                                                12.19
                                                
                                             | — | — | — | — | 
                                                11.86
                                                
                                             | — |  | — | — | — |  | — |  | — | — | 
| Equity-to-asset ratio | — | — | — | — | — | — | 
                                                0.782
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.728
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.694
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.729
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.726
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Rate of return on equity | — | — | — | — | — | 
                                                0.063
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.063
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                -0.015
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                -0.325
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.073
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Price-earnings ratio | — | — | — | — | — | 
                                                11.6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                19.7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                23.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Payout ratio | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.529
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.250
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.608
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Number of employees | 
                                                847
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,758
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                649
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                808
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                669
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                103
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                20
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                664
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1,504
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                743
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,291
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                742
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1,300
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                709
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,268
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                130
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                92
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                112
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                100
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                18
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                8
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                107
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                186
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                118
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                177
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                121
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                198
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                121
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                205
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Total shareholder return | — | — | — | — | — | — | 
                                                0.225
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.355
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.245
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.539
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.638
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Total return on share price index | — | — | — | — | — | — | 
                                                1.879
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                1.612
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.242
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1.337
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.049
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — |