v3.26.1
Deposits (Summary of Deposits) (Detail) - JPY (¥)
¥ in Millions
Mar. 31, 2026
Mar. 31, 2025
Deposits [Abstract]    
Time deposits ¥ 2,315,820 ¥ 2,073,007
Other deposits 309,736 376,805
Total ¥ 2,625,556 ¥ 2,449,812