Key Financial Data Of Reporting Company
| Concept | As at 2024-09-30 | 2024-04-01 to 2024-09-30 | 2024-04-01 to 2024-09-30 | As at 2024-09-30 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2023-09-30 | 2023-04-01 to 2023-09-30 | 2023-04-01 to 2023-09-30 | As at 2023-09-30 | 2022-04-01 to 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | As at 2022-09-30 | 2022-04-01 to 2022-09-30 | As at 2022-09-30 | 2022-04-01 to 2022-09-30 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||||||||||||||||
| Business results of reporting company | ||||||||||||||||||||
| Operating revenue | — | 
                                                7,783,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                10,915,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                10,633,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,829,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                6,608,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Ordinary income | — | — | 
                                                99,209,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                190,104,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                96,151,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                187,883,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                96,991,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                7,400,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                25,550,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                10,339,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                23,278,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                14,110,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,343,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,340,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                26,392,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,340,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                14,545,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Profit (loss) | — | 
                                                7,398,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                10,335,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                10,341,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,339,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                6,339,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Share capital | — | — | — | 
                                                70,895,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                70,895,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                70,895,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                70,895,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                70,895,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Total number of issued shares | — | — | — | 
                                                123,458,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | 
                                                125,370,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                125,370,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | 
                                                128,770,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | 
                                                128,770,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | 
| Net assets | 
                                                664,110,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                205,103,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                664,933,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                206,978,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                212,843,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                617,612,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                211,605,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                612,212,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                217,545,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                590,193,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                16,481,836,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                205,274,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                16,382,886,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                207,129,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                212,991,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                16,259,976,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                211,762,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,172,700,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                217,693,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                15,850,594,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets per share | 
                                                5,150.82
                                                
                                             | — | — | — | — | — | 
                                                5,083.31
                                                
                                             | — | — | — | — | 
                                                4,661.26
                                                
                                             | — | — | 
                                                4,491.95
                                                
                                             | — | — | — | 
                                                4,278.20
                                                
                                             | — | 
| Dividend paid per share | — | 
                                                22.50
                                                
                                             | — | — | 
                                                40.00
                                                
                                             | — | — | — | — | — |  | — | 
                                                37.00
                                                
                                             | — | — | — | — |  | — | — | 
| Basic earnings (loss) per share | — | — | 
                                                147.44
                                                
                                             | — | — | 
                                                176.99
                                                
                                             | — | — | — | 
                                                124.01
                                                
                                             | — | — | — | — | — | 
                                                159.18
                                                
                                             | — | — | — | 
                                                68.28
                                                
                                             | 
| Diluted earnings per share | — | — | 
                                                146.84
                                                
                                             | — | — | 
                                                176.28
                                                
                                             | — | — | — | 
                                                123.54
                                                
                                             | — | — | — | — | — | 
                                                158.63
                                                
                                             | — | — | — | 
                                                68.04
                                                
                                             | 
| Equity-to-asset ratio | 
                                                0.0400
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.9965
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.0403
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.9968
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.9969
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.0377
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.9972
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.0376
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.9973
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.0369
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                55,776,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                82,434,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -74,678,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -1,466,582,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -1,588,949,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -258,240,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                131,360,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                69,460,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                367,722,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                101,015,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -9,391,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -15,085,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -9,227,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -10,981,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -5,044,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                4,328,536,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                4,540,390,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                4,327,237,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,341,640,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,958,531,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Number of employees | 
                                                4,718
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                211
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                4,580
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                160
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                142
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                4,642
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                88
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4,570
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                74
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                4,670
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Average number of temporary employees | 
                                                2,542
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                13
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                2,511
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                18
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                23
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                2,569
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                23
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,567
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                22
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                2,586
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — |