Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	Total USD ($)	Shares of Common Stock [Member]	Common Stock and Additional Paid In Capital [Member] USD ($)	Treasury Stock [Member] USD ($)	Accumulated Other Comprehensive Loss [Member] USD ($)	Retained Earnings [Member] USD ($)
Beginning Balance at Jul. 31, 2013	$ 3,531		$ 3,201	$ (4,952)	$ 20	$ 5,262
Beginning Balance, shares at Jul. 31, 2013		299,503
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive loss	(12)				(1)	(11)
Issuance of stock under employee stock plans, shares		2,801
Issuance of stock under employee stock plans	80		(6)	86
Stock repurchases under stock repurchase programs, shares	(17,600)	(17,607)
Stock repurchases under stock repurchase programs	(1,400)		(280)	(1,120)
Cash dividends declared	(55)					(55)
Tax benefit from share-based compensation plans	33		33
Share-based compensation expense	47		47
Ending Balance at Oct. 31, 2013	2,224		2,995	(5,986)	19	5,196
Ending Balance, shares at Oct. 31, 2013		284,697
Beginning Balance at Jul. 31, 2014	3,078		3,561	(6,430)	(2)	5,949
Beginning Balance, shares at Jul. 31, 2014		284,950
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive loss	(89)				(5)	(84)
Issuance of stock under employee stock plans, shares		1,787
Issuance of stock under employee stock plans	47		47
Stock repurchases under stock repurchase programs, shares	(1,300)	(1,318)
Stock repurchases under stock repurchase programs	(114)			(114)
Cash dividends declared	(74)					(74)
Tax benefit from share-based compensation plans	18		18
Share-based compensation expense	61		61
Ending Balance at Oct. 31, 2014	$ 2,927		$ 3,687	$ (6,544)	$ (7)	$ 5,791
Ending Balance, shares at Oct. 31, 2014		285,419