v3.25.2
Derivative Financial Instruments (Fair Value Information on Derivative Instruments Recorded on Consolidated Balance Sheets) (Detail) - JPY (¥)
¥ in Billions
Mar. 31, 2025
Mar. 31, 2024
Derivatives, Fair Value [Line Items]    
Total derivative assets ¥ 20,748 ¥ 15,351
Total derivative liabilities ¥ 20,995 16,360
Derivative Asset, Statement of Financial Position [Extensible Enumeration] Trading account assets  
Derivative Liability, Statement of Financial Position [Extensible Enumeration] Trading account liabilities (Notes 15, 23 and 31)  
Interest rate contracts    
Derivatives, Fair Value [Line Items]    
Total derivative assets ¥ 14,896 9,505
Total derivative liabilities 16,071 10,696
Foreign exchange contracts    
Derivatives, Fair Value [Line Items]    
Total derivative assets 5,625 5,657
Total derivative liabilities 4,908 5,536
Equity contracts    
Derivatives, Fair Value [Line Items]    
Total derivative assets 146 123
Total derivative liabilities 62 158
Commodity contracts    
Derivatives, Fair Value [Line Items]    
Total derivative assets 20 19
Total derivative liabilities 20 18
Credit derivatives    
Derivatives, Fair Value [Line Items]    
Total derivative assets 51 47
Total derivative liabilities 53 62
Other    
Derivatives, Fair Value [Line Items]    
Total derivative assets 10 0
Total derivative liabilities (119) (110)
Not designated as hedges    
Derivatives, Fair Value [Line Items]    
Total derivative assets 20,744 15,341
Total derivative liabilities 20,992 16,360
Not designated as hedges | Interest rate contracts    
Derivatives, Fair Value [Line Items]    
Total derivative assets 14,896 9,505
Total derivative liabilities 16,071 10,696
Not designated as hedges | Foreign exchange contracts    
Derivatives, Fair Value [Line Items]    
Total derivative assets 5,621 5,647
Total derivative liabilities 4,905 5,536
Not designated as hedges | Equity contracts    
Derivatives, Fair Value [Line Items]    
Total derivative assets 146 123
Total derivative liabilities 62 158
Not designated as hedges | Commodity contracts    
Derivatives, Fair Value [Line Items]    
Total derivative assets 20 19
Total derivative liabilities 20 18
Not designated as hedges | Credit derivatives    
Derivatives, Fair Value [Line Items]    
Total derivative assets 51 47
Total derivative liabilities 53 62
Not designated as hedges | Other    
Derivatives, Fair Value [Line Items]    
Total derivative assets 10 0
Total derivative liabilities (119) (110)
Designated as hedges    
Derivatives, Fair Value [Line Items]    
Total derivative assets 4 10
Total derivative liabilities 3 0
Designated as hedges | Interest rate contracts    
Derivatives, Fair Value [Line Items]    
Total derivative assets 0 0
Total derivative liabilities 0 0
Designated as hedges | Foreign exchange contracts    
Derivatives, Fair Value [Line Items]    
Total derivative assets 4 10
Total derivative liabilities 3 0
Designated as hedges | Equity contracts    
Derivatives, Fair Value [Line Items]    
Total derivative assets 0 0
Total derivative liabilities 0 0
Designated as hedges | Commodity contracts    
Derivatives, Fair Value [Line Items]    
Total derivative assets 0 0
Total derivative liabilities 0 0
Designated as hedges | Credit derivatives    
Derivatives, Fair Value [Line Items]    
Total derivative assets 0 0
Total derivative liabilities 0 0
Designated as hedges | Other    
Derivatives, Fair Value [Line Items]    
Total derivative assets 0 0
Total derivative liabilities ¥ 0 ¥ 0