v3.26.1
Financial Risk Management - Disaggregation of Structured Finance Loans and Advances (Detail) - JPY (¥)
¥ in Millions
Mar. 31, 2026
Mar. 31, 2025
Disclosure of credit risk exposure [line items]    
Loans and advances ¥ 130,516,241 ¥ 125,190,819
Gross carrying amount [member]    
Disclosure of credit risk exposure [line items]    
Loans and advances 132,356,223 126,824,274
Gross carrying amount [member] | Real estate finance [member]    
Disclosure of credit risk exposure [line items]    
Loans and advances 7,073,251 6,235,358
Gross carrying amount [member] | Project finance [member]    
Disclosure of credit risk exposure [line items]    
Loans and advances 7,627,299 7,028,222
Gross carrying amount [member] | Other structured finance [Member]    
Disclosure of credit risk exposure [line items]    
Loans and advances 513,656 532,616
Gross carrying amount [member] | Structured finance [member]    
Disclosure of credit risk exposure [line items]    
Loans and advances ¥ 15,214,206 ¥ 13,796,196