Key Financial Data Of Reporting Company
| Concept | As at 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 2022-04-01 to 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | 2021-04-01 to 2022-03-31 | 2021-04-01 to 2022-03-31 | As at 2022-03-31 | As at 2022-03-31 | As at 2021-03-31 | 2020-04-01 to 2021-03-31 | 2020-04-01 to 2021-03-31 | As at 2021-03-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of reporting company | |||||||||||||||||||||
| Business results of reporting company | |||||||||||||||||||||
| Ordinary profit (loss) | — | — | 
                                                11,976,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                10,725,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,864,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,725,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                6,966,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                7,914,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,579,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,366,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                6,453,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,676,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) | — | — | — | — | 
                                                9,555,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,236,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                5,234,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                5,255,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                4,825,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Share capital | — | — | — | 
                                                5,158,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                5,158,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,158,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                5,158,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                5,158,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total number of issued shares | — | — | — | 
                                                48,564,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | 
                                                24,282,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | 
                                                24,282,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | 
                                                24,282,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | 
                                                24,282,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
| Net assets | — | 
                                                69,294,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                63,134,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                65,594,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                59,955,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                53,935,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                58,212,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                53,813,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                49,919,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                50,704,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                47,259,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                118,166,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                100,539,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                117,351,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                104,010,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                97,945,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                109,146,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                99,966,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                90,837,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                98,634,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                90,102,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | 
                                                1,527.53
                                                
                                             | — | 
                                                1,391.60
                                                
                                             | — | — | — | 
                                                1,434.11
                                                
                                             | 
                                                1,310.67
                                                
                                             | — | 
                                                1,152.06
                                                
                                             | 
                                                1,243.60
                                                
                                             | — | — | — | 
                                                1,151.50
                                                
                                             | 
                                                1,068.01
                                                
                                             | 
                                                1,086.90
                                                
                                             | — | — | 
                                                1,012.84
                                                
                                             | 
| Dividend paid per share | — | — | — | — | 
                                                110.00
                                                
                                             | 
                                                100.00
                                                
                                             | — | — | — | 
                                                80.00
                                                
                                             | — | — | — | 
                                                75.00
                                                
                                             | — | — | — | — | 
                                                70.00
                                                
                                             | — | — | 
| Interim dividend paid per share | — | — | — | — | 
                                                60.00
                                                
                                             | 
                                                30.00
                                                
                                             | — | — | — | 
                                                20.00
                                                
                                             | — | — | — | 
                                                20.00
                                                
                                             | — | — | — | — | 
                                                20.00
                                                
                                             | — | — | 
| Basic earnings (loss) per share | — | — | 
                                                211.62
                                                
                                             | — | 
                                                209.39
                                                
                                             | 
                                                135.00
                                                
                                             | 
                                                155.19
                                                
                                             | — | — | 
                                                112.09
                                                
                                             | — | — | 
                                                119.86
                                                
                                             | 
                                                112.76
                                                
                                             | 
                                                115.94
                                                
                                             | — | — | — | 
                                                103.80
                                                
                                             | 
                                                99.76
                                                
                                             | — | 
| Diluted earnings per share | — | — | 
                                                211.13
                                                
                                             | — | 
                                                208.90
                                                
                                             | 
                                                134.69
                                                
                                             | 
                                                154.83
                                                
                                             | — | — | 
                                                111.69
                                                
                                             | — | — | 
                                                119.44
                                                
                                             | 
                                                112.33
                                                
                                             | 
                                                115.50
                                                
                                             | — | — | — | 
                                                103.28
                                                
                                             | 
                                                99.26
                                                
                                             | — | 
| Equity-to-asset ratio | — | 
                                                0.586
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.627
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.558
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.576
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.550
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.532
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.537
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.548
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.513
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.523
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | 
                                                0.143
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.155
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.110
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.116
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.101
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.100
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.108
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.104
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.110
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.098
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | 
                                                8.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                8.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                12.8
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                11.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                8.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                7.8
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                8.6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                8.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                11.6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                12.1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Payout ratio | — | — | — | — | 
                                                0.382
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.370
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.357
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.333
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.337
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                14,238,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -13,562,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                12,820,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                7,004,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,917,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | — | 
                                                2,048,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -783,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -1,168,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                414,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                309,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -10,184,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,521,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -2,266,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -4,413,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -2,504,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                20,120,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                13,481,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                24,927,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                15,435,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                12,095,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Number of employees | 
                                                1,717
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,717
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1,208
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1,649
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,167
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1,132
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,608
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1,585
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,103
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,598
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                1,087
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Total shareholder return | — | — | — | 
                                                1.839
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                1.752
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.966
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                0.959
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.145
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Total return on share price index | — | — | — | 
                                                2.134
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                2.168
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1.534
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1.450
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.421
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |