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 | — | 
                                                8,540,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                21,702,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                7,728,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                17,837,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,714,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Ordinary income | — | — | 
                                                95,888,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                186,071,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                94,005,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                160,234,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                76,603,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                7,207,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                26,584,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                19,339,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                34,151,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                23,927,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,501,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                15,902,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                18,780,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,652,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                14,764,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Profit (loss) | — | 
                                                7,155,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                19,251,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                6,438,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                15,827,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,608,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Share capital | — | — | — | 
                                                60,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                60,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                60,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                60,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                60,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Total number of issued shares | — | — | — | 
                                                308,775,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | 
                                                312,370,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                312,370,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | 
                                                312,370,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | 
                                                312,370,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | 
| Net assets | 
                                                538,004,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                459,600,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                535,249,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                459,897,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                453,385,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                498,425,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                456,298,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                498,604,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                446,297,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                470,234,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                12,416,937,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                462,712,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                12,790,381,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                463,379,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                456,920,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                12,352,104,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                457,008,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,496,027,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                446,909,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                11,791,578,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets per share | 
                                                1,777.17
                                                
                                             | — | — | — | — | — | 
                                                1,760.62
                                                
                                             | — | — | — | — | 
                                                1,635.43
                                                
                                             | — | — | 
                                                1,603.30
                                                
                                             | — | — | — | 
                                                1,512.11
                                                
                                             | — | 
| Dividend paid per share | — | 
                                                23.50
                                                
                                             | — | — | 
                                                37.00
                                                
                                             | — | — | — | — | — | 
                                                18.00
                                                
                                             | — | 
                                                27.00
                                                
                                             | — | — | — | — | 
                                                13.50
                                                
                                             | — | — | 
| Basic earnings (loss) per share | — | — | 
                                                60.57
                                                
                                             | — | — | 
                                                90.35
                                                
                                             | — | — | — | 
                                                53.82
                                                
                                             | — | — | — | — | — | 
                                                40.25
                                                
                                             | — | — | — | 
                                                32.41
                                                
                                             | 
| Diluted earnings per share | — | — | 
                                                60.54
                                                
                                             | — | — | 
                                                90.30
                                                
                                             | — | — | — | 
                                                53.79
                                                
                                             | — | — | — | — | — | 
                                                40.22
                                                
                                             | — | — | — | 
                                                32.40
                                                
                                             | 
| Equity-to-asset ratio | 
                                                0.0433
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.9929
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.0418
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.9922
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.9919
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.0403
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.9981
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.0433
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.9983
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.0398
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                -994,062,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                783,335,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                617,670,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -468,742,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -37,449,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -137,476,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -119,386,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -100,482,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                65,827,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -126,504,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -7,883,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -15,919,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -9,586,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -8,100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -3,840,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                1,663,612,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,803,038,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,662,623,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,154,953,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,398,199,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Number of employees | 
                                                3,743
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                16
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                3,682
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                15
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                14
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                3,760
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                17
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                3,739
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                19
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                3,825
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Average number of temporary employees | 
                                                1,356
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                1,320
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                1,315
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,357
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1,389
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — |