Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 1,826	$ 1,557	$ 1,329
Other comprehensive income (loss), net of income taxes:
Unrealized gain (loss) on available-for-sale debt securities	5	3	(2)
Foreign currency translation loss	(1)	(3)	(12)
Total other comprehensive income (loss), net	4	0	(14)
Comprehensive income	$ 1,830	$ 1,557	$ 1,315