Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 31, 2021	Oct. 31, 2020	Oct. 31, 2021	Oct. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 468	$ 1,081	$ 1,472	$ 3,805
Other comprehensive income (loss), net of reclassification adjustments:
Foreign currency translation and other losses	(17)	(6)	(42)	(1)
Unrealized gains (losses) on marketable securities and privately held debt securities	(26)	(11)	(47)	13
Other comprehensive income (loss), before tax	(43)	(17)	(89)	12
Tax effect	5	1	9	(3)
Other comprehensive income (loss), net	(38)	(16)	(80)	9
Comprehensive income	$ 430	$ 1,065	$ 1,392	$ 3,814