v3.26.3
Investment in Securities (Summary of Investment in Securities) (Detail) - JPY (¥)
¥ in Millions
Sep. 30, 2026
Mar. 31, 2026
Investments, Debt and Equity Securities [Abstract]    
Equity securities [1] ¥ 639,339 ¥ 782,137
Available-for-sale debt securities 2,333,404 2,360,361
Total ¥ 2,972,743 ¥ 3,142,498
[1] The amount of assets under management of variable annuity and variable life insurance contracts included in equity securities were ¥137,933 million and ¥146,898 million as of March 31, 2026 and September 30, 2026, respectively. The amount of investment funds that elected the fair value option and were included in equity securities were ¥24,845 million and ¥25,231 million as of March 31, 2026 and September 30, 2026, respectively.