Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (USD $) In Millions, except Share data, unless otherwise specified	Total USD ($)	Common Stock [Member]	Common Stock and Additional Paid In Capital USD ($)	Treasury Stock USD ($)	Accumulated Other Comprehensive Income USD ($)	Retained Earnings USD ($)
Beginning Balance at Jul. 31, 2010	$ 2,821		$ 2,728	$ (3,315)	$ 11	$ 3,397
Beginning Balance, shares at Jul. 31, 2010		313,861,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	691		0	0	0	691
Other comprehensive income, net of tax	4		0	0	4	0
Comprehensive net income	695
Issuance of treasury stock under employee stock plans	235		(73)	308	0	0
Issuance of treasury stock under employee stock plans, shares		13,069,000
Stock repurchases under stock repurchase programs	(1,110)		0	(1,110)	0	0
Stock repurchases under stock repurchase programs, shares	(23,349,000)	(23,349,000)
Tax benefit from share-based compensation plans	68		68	0	0	0
Share-based compensation expense	112		112	0	0	0
Ending Balance at Apr. 30, 2011	2,821		2,835	(4,117)	15	4,088
Ending Balance, shares at Apr. 30, 2011		303,581,000
Beginning Balance at Jul. 31, 2011	2,616		2,886	(4,316)	15	4,031
Beginning Balance, shares at Jul. 31, 2011		300,597,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	788		0	0	0	788
Other comprehensive income, net of tax	14		0	0	14	0
Comprehensive net income	802
Issuance of treasury stock under employee stock plans	160		(63)	231	0	(8)
Issuance of treasury stock under employee stock plans, shares		8,705,000
Stock repurchases under stock repurchase programs	(793)		0	(793)	0	0
Stock repurchases under stock repurchase programs, shares	(14,973,000)	(14,973,000)
Cash dividends declared ($0.45 per share)	(134)					(134)
Tax benefit from share-based compensation plans	64		64	0	0	0
Share-based compensation expense	120		120	0	0	0
Ending Balance at Apr. 30, 2012	$ 2,835		$ 3,007	$ (4,878)	$ 29	$ 4,677
Ending Balance, shares at Apr. 30, 2012		294,329,000