v3.26.1
Trading Liabilities - Summary of Trading Liabilities (Detail) - JPY (¥)
¥ in Millions
Mar. 31, 2026
Mar. 31, 2025
Disclosure of financial liabilities [line items]    
Trading liabilities ¥ 4,130,591 ¥ 4,838,439
Debt instruments [member]    
Disclosure of financial liabilities [line items]    
Trading liabilities 4,102,347 4,489,159
Equity instruments [member]    
Disclosure of financial liabilities [line items]    
Trading liabilities ¥ 28,244 ¥ 349,280