Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2017	Apr. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 964	$ 1,026	$ 947	$ 1,019
Other comprehensive income (loss), net of income taxes:
Unrealized gains on available-for-sale debt securities	0	0	(1)	0
Foreign currency translation gains (losses)	(2)	16	(3)	4
Total other comprehensive income (loss), net	(2)	16	(4)	4
Comprehensive income	$ 962	$ 1,042	$ 943	$ 1,023