Key Financial Data Of Reporting Company
| Concept | 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 | ||||||||||||||||||||
| Operating revenue | — | — | — | 
                                                52,285,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                53,965,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                46,783,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                32,926,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                35,966,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Ordinary profit (loss) | — | 
                                                42,660,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                13,500,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                25,799,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                37,815,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                22,279,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                60,378,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                15,670,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                75,740,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                20,456,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                49,594,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) | — | — | — | 
                                                12,515,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                41,392,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                22,626,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                33,326,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                25,139,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Share capital | — | — | 
                                                10,790,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                10,790,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                10,790,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                10,790,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                10,648,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total number of issued shares | — | — | 
                                                389,559,436
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | 
                                                389,559,436
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | 
                                                389,559,436
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | 
                                                389,559,436
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | 
                                                389,397,652
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
| Net assets | 
                                                413,682,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                311,304,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                409,200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                310,436,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                290,079,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                389,814,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                387,414,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                293,246,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                362,139,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                289,296,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | 
                                                1,050,191,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                522,201,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,035,014,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                539,430,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                506,560,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,026,415,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,053,016,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                483,232,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                941,103,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                484,253,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | 
                                                1,062.25
                                                
                                             | — | 
                                                847.35
                                                
                                             | — | — | — | 
                                                1,048.61
                                                
                                             | 
                                                845.63
                                                
                                             | — | 
                                                786.02
                                                
                                             | 
                                                986.05
                                                
                                             | — | — | — | 
                                                957.72
                                                
                                             | 
                                                784.81
                                                
                                             | 
                                                884.69
                                                
                                             | — | — | 
                                                774.57
                                                
                                             | 
| Dividend paid per share | — | — | — | 
                                                32.00
                                                
                                             | 
                                                32.00
                                                
                                             | — | — | — | 
                                                32.00
                                                
                                             | — | — | — | 
                                                32.00
                                                
                                             | — | — | — | — | 
                                                30.00
                                                
                                             | — | — | 
| Interim dividend paid per share | — | — | — | 
                                                16.00
                                                
                                             | 
                                                16.00
                                                
                                             | — | — | — | 
                                                16.00
                                                
                                             | — | — | — | 
                                                15.00
                                                
                                             | — | — | — | — | 
                                                15.00
                                                
                                             | — | — | 
| Basic earnings (loss) per share | — | 
                                                29.32
                                                
                                             | — | 
                                                34.07
                                                
                                             | 
                                                112.72
                                                
                                             | 
                                                67.87
                                                
                                             | — | — | 
                                                60.68
                                                
                                             | — | — | 
                                                83.16
                                                
                                             | 
                                                89.20
                                                
                                             | 
                                                147.70
                                                
                                             | — | — | — | 
                                                67.33
                                                
                                             | 
                                                70.92
                                                
                                             | — | 
| Diluted earnings per share | — | 
                                                29.31
                                                
                                             | — |  |  | 
                                                67.86
                                                
                                             | — | — |  | — | — | 
                                                83.16
                                                
                                             |  | 
                                                147.68
                                                
                                             | — | — | — |  | 
                                                70.91
                                                
                                             | — | 
| Equity-to-asset ratio | 
                                                0.372
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.596
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.372
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.575
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.573
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.355
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.340
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.607
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.351
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.597
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | 
                                                0.028
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.040
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.138
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.067
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.078
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.086
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.114
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.160
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.092
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.085
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | 
                                                36.9
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                31.8
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                12.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                20.4
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                24.6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                18.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                17.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                10.5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                27.4
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                26.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Payout ratio | — | — | — | 
                                                0.939
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.284
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.527
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.359
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.446
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | 
                                                82,446,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                9,883,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                38,035,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                20,852,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                36,212,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -13,529,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                6,329,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -32,792,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -11,292,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -9,831,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -45,848,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,097,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -28,839,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -8,698,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -12,767,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                207,520,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                180,067,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                159,081,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                180,697,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                176,042,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Number of employees | 
                                                29,386
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                174
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                28,894
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                149
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                266
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                27,936
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                25,522
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                260
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                24,775
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                248
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                13,007
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                14
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                11,061
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                28
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                32
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                11,027
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                10,361
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                20
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                10,793
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                20
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Total shareholder return | — | — | 
                                                1.138
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                1.387
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1.458
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1.474
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.720
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Total return on share price index | — | — | 
                                                1.883
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                2.134
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1.482
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1.471
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.542
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |