v3.26.1
Related-Party Transactions - Transactions with Key Management Personnel and Their Close Family Members (Detail) - JPY (¥)
¥ in Millions
Mar. 31, 2026
Mar. 31, 2025
Assets:    
Loans and advances ¥ 130,516,241 ¥ 125,190,819
Liabilities:    
Deposits 201,930,427 190,022,742
Others 16,767,384 10,821,441
Key management personnel of entity or parent [member]    
Assets:    
Loans and advances 442 734
Liabilities:    
Deposits 2,482 2,680
Others ¥ 55 ¥ 156