v3.26.1
Fair Value Measurements - Additional Information (Detail)
¥ in Millions
12 Months Ended
Mar. 31, 2024
JPY (¥)
Fair Value, Measurements, Recurring | Foreign municipal bond securities  
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]  
Transferred from level 2 to level 3 ¥ 6,818