Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Oct. 31, 2020	Oct. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 198	$ 57
Other comprehensive income (loss), net of income taxes:
Unrealized gain (loss) on available-for-sale debt securities	(1)	1
Foreign currency translation loss	(2)	0
Total other comprehensive income (loss), net	(3)	1
Comprehensive income	$ 195	$ 58