v3.26.1
Income Taxes - Profit (Loss) Before Income Taxes and Income Tax Expense (Detail) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Disclosure of income taxes [Line Items]      
Profit (loss) before income taxes ¥ (403,300) ¥ 1,317,640 ¥ 1,642,384
Income tax expense (benefit):      
Current taxes 214,079 527,998 625,158
Deferred taxes (264,356) (113,392) (165,364)
Total (50,277) 414,606 459,794
Japan [member]      
Disclosure of income taxes [Line Items]      
Profit (loss) before income taxes (800,827) 180,912 148,651
Income tax expense (benefit):      
Current taxes (17,268) 28,922 19,081
Deferred taxes (187,375) (3,821) 34,265
Total (204,643) 25,101 53,346
Foreign [member]      
Disclosure of income taxes [Line Items]      
Profit (loss) before income taxes 397,527 1,136,728 1,493,733
Income tax expense (benefit):      
Current taxes 231,347 499,076 606,077
Deferred taxes (76,981) (109,571) (199,629)
Total ¥ 154,366 ¥ 389,505 ¥ 406,448