v3.26.1
Premises and Equipment - Additional Information (Detail) - JPY (¥)
¥ in Millions
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Property, Plant and Equipment [Line Items]      
Depreciation and amortization ¥ 270,162 ¥ 229,606 ¥ 214,157