v3.26.1
Derivative Financial Instruments and Hedging (Credit Derivatives) (Detail) - Credit Default Swap - JPY (¥)
¥ in Millions
Mar. 31, 2026
Mar. 31, 2025
Credit Derivatives [Line Items]    
Maximum potential amount of future payment under the credit derivative ¥ 1,000 ¥ 1,000
Fair value of the credit derivative ¥ (2) ¥ (3)