v3.26.1
Segment and geographic information - Business segments' results (Detail) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Segment Reporting Information [Line Items]      
Non-interest revenue ¥ 2,080,575 ¥ 1,810,431 ¥ 1,546,779
Net interest revenue 78,867 83,603 25,562
Net revenue 2,159,442 1,894,034 1,572,341
Non-interest expenses [1] 1,627,892 1,420,521 1,288,150
Income before income taxes 531,550 473,513 284,191
Wealth Management [Member]      
Segment Reporting Information [Line Items]      
Non-interest revenue 473,282 422,617 380,563
Net interest revenue 14,624 10,934 6,461
Net revenue 487,906 433,551 387,024
Non-interest expenses [1] 283,882 267,369 268,035
Income before income taxes 204,024 166,182 118,989
Investment Management [Member]      
Segment Reporting Information [Line Items]      
Non-interest revenue 248,388 181,010 149,575
Net interest revenue 10,128 11,463 4,568
Net revenue 258,516 192,473 154,143
Non-interest expenses [1] 170,219 102,882 93,945
Income before income taxes 88,297 89,591 60,198
Wholesale [Member]      
Segment Reporting Information [Line Items]      
Non-interest revenue 1,168,966 1,015,803 875,664
Net interest revenue (6,737) 42,135 (9,517)
Net revenue 1,162,229 1,057,938 866,147
Non-interest expenses [1] 961,662 891,656 812,236
Income before income taxes 200,567 166,282 53,911
Banking [Member]      
Segment Reporting Information [Line Items]      
Non-interest revenue 42,081 36,344 35,244
Net interest revenue 11,837 10,828 7,617
Net revenue 53,918 47,172 42,861
Non-interest expenses [1] 39,902 30,815 27,755
Income before income taxes 14,016 16,357 15,106
Other (Incl. elimination) [Member]      
Segment Reporting Information [Line Items]      
Non-interest revenue 147,858 154,657 105,733
Net interest revenue 49,015 8,243 16,433
Net revenue 196,873 162,900 122,166
Non-interest expenses [1] 172,227 127,799 86,179
Income before income taxes ¥ 24,646 ¥ 35,101 ¥ 35,987
[1] Includes primarily personnel expenses, occupancy, technology, and professional fees.