Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Millions	Total	Common Stock	Additional Paid-In Capital	Treasury Stock	Accumulated Other Comprehensive Loss	Retained Earnings
Beginning Balance (in shares) at Jul. 31, 2015		277,706
Beginning Balance at Jul. 31, 2015	$ 2,332	$ 3	$ 4,007	$ (7,675)	$ (30)	$ 6,027
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	977				(2)	979
Issuance of stock under employee stock plans, net of shares withheld for employee taxes (in shares)		4,963
Issuance of stock under employee stock plans, net of shares withheld for employee taxes	89		89
Stock repurchases under stock repurchase programs (in shares)		(24,816)
Stock repurchases under stock repurchase programs	(2,264)			(2,264)
Dividends and dividend rights declared	(319)					(319)
Tax benefit from share-based compensation plans	59		59
Share-based compensation expense	287		287
Ending Balance (in shares) at Jul. 31, 2016		257,853
Ending Balance at Jul. 31, 2016	1,161	$ 3	4,442	(9,939)	(32)	6,687
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle	2		6			(4)
Comprehensive income	981				10	971
Issuance of stock under employee stock plans, net of shares withheld for employee taxes (in shares)		4,715
Issuance of stock under employee stock plans, net of shares withheld for employee taxes	73		73
Stock repurchases under stock repurchase programs (in shares)		(6,900)
Stock repurchases under stock repurchase programs	(839)			(839)
Dividends and dividend rights declared	(357)					(357)
Share-based compensation expense	$ 333		333
Ending Balance (in shares) at Jul. 31, 2017	255,668	255,668
Ending Balance at Jul. 31, 2017	$ 1,354	$ 3	4,854	(10,778)	(22)	7,297
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	1,198				(13)	1,211
Issuance of stock under employee stock plans, net of shares withheld for employee taxes (in shares)		4,818
Issuance of stock under employee stock plans, net of shares withheld for employee taxes	96		96
Stock repurchases under stock repurchase programs (in shares)		(1,870)
Stock repurchases under stock repurchase programs	(272)			(272)
Dividends and dividend rights declared	(407)					(407)
Share-based compensation expense	$ 385		385
Ending Balance (in shares) at Jul. 31, 2018	258,616	258,616
Ending Balance at Jul. 31, 2018	$ 2,354	$ 3	$ 5,335	$ (11,050)	$ (35)	$ 8,101