Taxes (Schedule of Income Before Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Income Tax Disclosure [Abstract]
U.S.	$ 20,003	$ 17,098	$ 15,875
Non-U.S.	561	3,018	(4,415)
Income before income taxes	$ 20,564	$ 20,116	$ 11,460