v3.26.1
Estimated Fair Value of Financial Instruments (Information about Carrying Amount of Financial Instruments Reported in Consolidated Balance Sheets and Related Market or Fair Value) (Parenthetical) (Detail) - JPY (¥)
¥ in Millions
Mar. 31, 2026
Mar. 31, 2025
Estimated fair value    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Investment funds ¥ 168,854 ¥ 118,666