Condensed Consolidated Statements of Stockholders' Equity (USD $) In Millions, except Share data in Thousands, unless otherwise specified	Total USD ($)	Shares of Common Stock	Common Stock and Additional Paid In Capital USD ($)	Treasury Stock USD ($)	Accumulated Other Comprehensive Income USD ($)	Retained Earnings USD ($)
Beginning Balance at Jul. 31, 2012	$ 2,744		$ 3,018	$ (4,911)	$ 25	$ 4,612
Beginning Balance, shares at Jul. 31, 2012		295,289
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive loss	(15)				4	(19)
Issuance of treasury stock under employee stock plans, shares		2,688
Issuance of treasury stock under employee stock plans	73		3	70
Stock repurchases under stock repurchase programs, shares	(1,700)	(1,694)
Stock repurchases under stock repurchase programs	(100)			(100)
Cash dividends declared	(50)					(50)
Tax benefit from share-based compensation plans	44		44
Share-based compensation expense	49		49
Ending Balance at Oct. 31, 2012	2,745		3,114	(4,941)	29	4,543
Ending Balance, shares at Oct. 31, 2012		296,283
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 treasury stock under employee stock plans, shares		2,801
Issuance of treasury 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