v3.26.1
Fair Value of Financial Assets and Liabilities - Carrying Amounts of Financial Assets and Liabilities Carried at Fair Value (Detail) - JPY (¥)
¥ in Millions
Mar. 31, 2026
Mar. 31, 2025
Financial assets:    
Trading assets ¥ 6,890,217 ¥ 6,176,613
Derivative financial instruments 10,093,100 8,313,016
Financial assets at fair value through profit or loss 2,705,113 2,902,969
Debt instruments 23,268,702 28,008,280
Total 303,334,635 287,137,388
Financial liabilities:    
Trading liabilities 4,130,591 4,838,439
Derivative financial instruments 11,472,444 9,303,258
Financial liabilities designated at fair value through profit or loss 661,424 597,846
Total 289,581,279 274,363,711
At fair value [member]    
Financial assets:    
Trading assets 6,890,217 6,176,613
Derivative financial instruments 10,093,100 8,313,016
Financial assets at fair value through profit or loss 2,705,113 2,902,969
Debt instruments 23,268,702 28,008,280
Investment securities at fair value through other comprehensive income 28,774,141 33,179,136
Total 48,462,571 50,571,734
Financial liabilities:    
Trading liabilities 4,130,591 4,838,439
Derivative financial instruments 11,472,444 9,303,258
Financial liabilities designated at fair value through profit or loss 661,424 597,846
Others (51,570) (25,320)
Total 16,212,889 14,714,223
At fair value [member] | Level 1 [member]    
Financial assets:    
Trading assets 5,251,287 4,829,551
Derivative financial instruments 140,770 75,575
Financial assets at fair value through profit or loss 368,866 441,176
Debt instruments 14,047,305 18,926,323
Investment securities at fair value through other comprehensive income 18,684,184 23,325,137
Total 24,445,107 28,671,439
Financial liabilities:    
Trading liabilities 3,793,393 4,504,675
Derivative financial instruments 111,900 73,303
Total 3,905,293 4,577,978
At fair value [member] | Level 2 [member]    
Financial assets:    
Trading assets 1,638,930 1,305,682
Derivative financial instruments 9,947,581 8,229,843
Financial assets at fair value through profit or loss 1,389,094 1,532,527
Debt instruments 9,221,397 9,081,957
Investment securities at fair value through other comprehensive income 9,411,582 9,303,551
Total 22,387,187 20,371,603
Financial liabilities:    
Trading liabilities 337,198 333,764
Derivative financial instruments 11,348,039 9,219,873
Financial liabilities designated at fair value through profit or loss 539,747 468,168
Others (19,106) (11,203)
Total 12,205,878 10,010,602
At fair value [member] | Level 3 [member]    
Financial assets:    
Trading assets   41,380
Derivative financial instruments 4,749 7,598
Financial assets at fair value through profit or loss 947,153 929,266
Investment securities at fair value through other comprehensive income 678,375 550,448
Total 1,630,277 1,528,692
Financial liabilities:    
Derivative financial instruments 12,505 10,082
Financial liabilities designated at fair value through profit or loss 121,677 129,678
Others (32,464) (14,117)
Total 101,718 125,643
At fair value [member] | Debt instruments [member]    
Financial assets:    
Trading assets 6,476,194 5,511,465
Financial assets at fair value through profit or loss 2,620,759 2,820,665
Debt instruments 10,983,239 11,288,683
Financial liabilities:    
Trading liabilities 4,102,347 4,489,159
At fair value [member] | Debt instruments [member] | Level 1 [member]    
Financial assets:    
Trading assets 4,840,674 4,165,582
Financial assets at fair value through profit or loss 367,115 439,183
Debt instruments 1,785,661 2,218,297
Financial liabilities:    
Trading liabilities 3,767,152 4,157,599
At fair value [member] | Debt instruments [member] | Level 2 [member]    
Financial assets:    
Trading assets 1,635,520 1,304,503
Financial assets at fair value through profit or loss 1,388,809 1,532,360
Debt instruments 9,197,578 9,070,386
Financial liabilities:    
Trading liabilities 335,195 331,560
At fair value [member] | Debt instruments [member] | Level 3 [member]    
Financial assets:    
Trading assets   41,380
Financial assets at fair value through profit or loss 864,835 849,122
At fair value [member] | Equity instruments [member]    
Financial assets:    
Trading assets 414,023 665,148
Financial liabilities:    
Trading liabilities 28,244 349,280
At fair value [member] | Equity instruments [member] | Level 1 [member]    
Financial assets:    
Trading assets 410,613 663,969
Financial liabilities:    
Trading liabilities 26,241 347,076
At fair value [member] | Equity instruments [member] | Level 2 [member]    
Financial assets:    
Trading assets 3,410 1,179
Financial liabilities:    
Trading liabilities 2,003 2,204
At fair value [member] | Equity instruments [member]    
Financial assets:    
Financial assets at fair value through profit or loss 84,354 82,304
At fair value [member] | Equity instruments [member] | Level 1 [member]    
Financial assets:    
Financial assets at fair value through profit or loss 1,751 1,993
At fair value [member] | Equity instruments [member] | Level 2 [member]    
Financial assets:    
Financial assets at fair value through profit or loss 285 167
At fair value [member] | Equity instruments [member] | Level 3 [member]    
Financial assets:    
Financial assets at fair value through profit or loss 82,318 80,144
At fair value [member] | Interest rate derivatives [member]    
Financial assets:    
Derivative financial instruments 5,005,430 5,070,299
Financial liabilities:    
Derivative financial instruments 5,936,809 5,780,881
At fair value [member] | Interest rate derivatives [member] | Level 1 [member]    
Financial assets:    
Derivative financial instruments 67,936 40,359
Financial liabilities:    
Derivative financial instruments 59,341 52,418
At fair value [member] | Interest rate derivatives [member] | Level 2 [member]    
Financial assets:    
Derivative financial instruments 4,937,480 5,029,763
Financial liabilities:    
Derivative financial instruments 5,869,756 5,724,113
At fair value [member] | Interest rate derivatives [member] | Level 3 [member]    
Financial assets:    
Derivative financial instruments 14 177
Financial liabilities:    
Derivative financial instruments 7,712 4,350
At fair value [member] | Currency derivatives [member]    
Financial assets:    
Derivative financial instruments 4,958,912 3,051,826
Financial liabilities:    
Derivative financial instruments 5,420,539 3,461,085
At fair value [member] | Currency derivatives [member] | Level 1 [member]    
Financial liabilities:    
Derivative financial instruments 2,160 94
At fair value [member] | Currency derivatives [member] | Level 2 [member]    
Financial assets:    
Derivative financial instruments 4,957,489 3,050,767
Financial liabilities:    
Derivative financial instruments 5,415,237 3,458,041
At fair value [member] | Currency derivatives [member] | Level 3 [member]    
Financial assets:    
Derivative financial instruments 1,423 1,059
Financial liabilities:    
Derivative financial instruments 3,142 2,950
At fair value [member] | Equity derivatives [member]    
Financial assets:    
Derivative financial instruments 67,937 161,801
Financial liabilities:    
Derivative financial instruments 45,616 22,092
At fair value [member] | Equity derivatives [member] | Level 1 [member]    
Financial assets:    
Derivative financial instruments 62,019 33,409
Financial liabilities:    
Derivative financial instruments 41,028 18,995
At fair value [member] | Equity derivatives [member] | Level 2 [member]    
Financial assets:    
Derivative financial instruments 2,811 122,320
Financial liabilities:    
Derivative financial instruments 3,064 404
At fair value [member] | Equity derivatives [member] | Level 3 [member]    
Financial assets:    
Derivative financial instruments 3,107 6,072
Financial liabilities:    
Derivative financial instruments 1,524 2,693
At fair value [member] | Commodity derivatives [member]    
Financial assets:    
Derivative financial instruments 34,909 5,652
Financial liabilities:    
Derivative financial instruments 33,753 4,384
At fair value [member] | Commodity derivatives [member] | Level 1 [member]    
Financial assets:    
Derivative financial instruments 10,815 1,807
Financial liabilities:    
Derivative financial instruments 9,371 1,796
At fair value [member] | Commodity derivatives [member] | Level 2 [member]    
Financial assets:    
Derivative financial instruments 24,094 3,845
Financial liabilities:    
Derivative financial instruments 24,382 2,588
At fair value [member] | Credit derivatives [member]    
Financial assets:    
Derivative financial instruments 25,912 23,438
Financial liabilities:    
Derivative financial instruments 35,727 34,816
At fair value [member] | Credit derivatives [member] | Level 2 [member]    
Financial assets:    
Derivative financial instruments 25,707 23,148
Financial liabilities:    
Derivative financial instruments 35,600 34,727
At fair value [member] | Credit derivatives [member] | Level 3 [member]    
Financial assets:    
Derivative financial instruments 205 290
Financial liabilities:    
Derivative financial instruments 127 89
At fair value [member] | Japanese government bonds [member]    
Financial assets:    
Debt instruments 5,476,428 11,180,546
At fair value [member] | Japanese government bonds [member] | Level 1 [member]    
Financial assets:    
Debt instruments 5,476,428 11,180,546
At fair value [member] | U.S. Treasury and other U.S. government agency bonds [member]    
Financial assets:    
Debt instruments 6,809,035 5,539,051
At fair value [member] | U.S. Treasury and other U.S. government agency bonds [member] | Level 1 [member]    
Financial assets:    
Debt instruments 6,785,216 5,527,480
At fair value [member] | U.S. Treasury and other U.S. government agency bonds [member] | Level 2 [member]    
Financial assets:    
Debt instruments 23,819 11,571
At fair value [member] | Investment securities [member]    
Financial assets:    
Debt instruments 5,505,439 5,170,856
At fair value [member] | Investment securities [member] | Level 1 [member]    
Financial assets:    
Debt instruments 4,636,879 4,398,814
At fair value [member] | Investment securities [member] | Level 2 [member]    
Financial assets:    
Debt instruments 190,185 221,594
At fair value [member] | Investment securities [member] | Level 3 [member]    
Financial assets:    
Debt instruments ¥ 678,375 ¥ 550,448