v3.26.1
Income and Expenses Relating to Life Insurance Operations - Life Insurance Premiums and Related Investment Income (Detail) - JPY (¥)
¥ in Millions
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Net Investment Income [Line Items]      
Total revenue ¥ 3,330,831 ¥ 2,874,821 ¥ 2,814,361
Life insurance premiums      
Net Investment Income [Line Items]      
Total revenue 506,120 481,432 459,655
Life insurance related investment income      
Net Investment Income [Line Items]      
Total revenue [1] 134,039 33,827 99,268
Life insurance premiums and related investment income      
Net Investment Income [Line Items]      
Total revenue ¥ 640,159 ¥ 515,259 ¥ 558,923
[1] Life insurance related investment income in fiscal 2024, 2025 and 2026 include net unrealized holding gains of ¥43,301 million, ¥2,577 million and ¥48,946 million on equity securities held as of March 31, 2024, 2025 and 2026, respectively.