Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Millions	Total	Shares of Common Stock	Common Stock and Additional Paid-In Capital	Treasury Stock	Accumulated Other Comprehensive Loss	Retained Earnings
Beginning Balance, shares at Jul. 31, 2015		277,706
Beginning Balance at Jul. 31, 2015	$ 2,332		$ 4,010	$ (7,675)	$ (30)	$ 6,027
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	1,023				4	1,019
Issuance of stock under employee stock plans, net of shares withheld for employee taxes, shares		2,767
Issuance of stock under employee stock plans, net of shares withheld for employee taxes	$ 89		89
Stock repurchases under stock repurchase programs, shares	(24,100)	(24,085)
Stock repurchases under stock repurchase programs	$ (2,190)			(2,190)
Dividends and dividend rights declared	(241)					(241)
Tax benefit from share-based compensation plans	30		30
Share-based compensation expense	205		205
Ending Balance, shares at Apr. 30, 2016		256,388
Ending Balance at Apr. 30, 2016	1,248		4,334	(9,865)	(26)	6,805
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle	2		6			(4)
Beginning Balance, shares at Jul. 31, 2016		257,853
Beginning Balance at Jul. 31, 2016	1,161		4,445	(9,939)	(32)	6,687
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	943				(4)	947
Issuance of stock under employee stock plans, net of shares withheld for employee taxes, shares		2,642
Issuance of stock under employee stock plans, net of shares withheld for employee taxes	$ 89		89
Stock repurchases under stock repurchase programs, shares	(4,200)	(4,241)
Stock repurchases under stock repurchase programs	$ (478)			(478)
Dividends and dividend rights declared	(267)					(267)
Share-based compensation expense	247		247
Ending Balance, shares at Apr. 30, 2017		256,254
Ending Balance at Apr. 30, 2017	$ 1,697		$ 4,787	$ (10,417)	$ (36)	$ 7,363