v3.26.1
Assets Pledged and Received as Collateral - Additional information (Detail) - JPY (¥)
¥ in Millions
Mar. 31, 2026
Mar. 31, 2025
Disclosure of detailed information about financial instruments [abstract]    
Loaned securities for which the borrowers have the right to sell or repledge ¥ 14,478,581 ¥ 17,619,448
Fair value of securities and bills accepted as collateral 32,574,165 27,668,614
Fair value of securities sold or repledged to others ¥ 17,437,371 ¥ 13,400,920