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	(58)				(10)	(48)
Issuance of stock under employee stock plans, shares		4,188
Issuance of stock under employee stock plans	133		33	100
Stock repurchases under stock repurchase programs, shares	(20,200)	(20,178)
Stock repurchases under stock repurchase programs	(1,402)			(1,402)
Dividends and dividend rights declared	(111)					(111)
Tax benefit from share-based compensation plans	43		43
Share-based compensation expense	99		99
Ending Balance at Jan. 31, 2014	2,235		3,376	(6,254)	10	5,103
Ending Balance, shares at Jan. 31, 2014		283,513
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	(170)				(20)	(150)
Issuance of stock under employee stock plans, shares		3,463
Issuance of stock under employee stock plans	101		101
Stock repurchases under stock repurchase programs, shares	(7,500)	(7,473)
Stock repurchases under stock repurchase programs	(668)			(668)
Dividends and dividend rights declared	(147)					(147)
Tax benefit from share-based compensation plans	38		38
Share-based compensation expense	122		122
Ending Balance at Jan. 31, 2015	$ 2,354		$ 3,822	$ (7,098)	$ (22)	$ 5,652
Ending Balance, shares at Jan. 31, 2015		280,940