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, 2011	$ 2,616		$ 2,886	$ (4,316)	$ 15	$ 4,031
Beginning Balance, shares at Jul. 31, 2011		300,597
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(64)		0	0	0	(64)
Other comprehensive income (loss), net of income taxes	(6)		0	0	(6)	0
Comprehensive loss	(70)
Issuance of treasury stock under employee stock plans	45		(37)	87	0	(5)
Issuance of treasury stock under employee stock plans, shares		3,219
Tax benefit from share-based compensation plans	30		30	0	0	0
Stock repurchases under stock repurchase programs	(255)		0	(255)	0	0
Stock repurchases under stock repurchase programs, shares	(5,200)	(5,211)
Cash dividends declared	(45)					(45)
Share-based compensation expense	40		40	0	0	0
Ending Balance at Oct. 31, 2011	2,361		2,919	(4,484)	9	3,917
Ending Balance, shares at Oct. 31, 2011		298,605
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]
Net loss	(19)		0	0	0	(19)
Other comprehensive income (loss), net of income taxes	4		0	0	4	0
Comprehensive loss	(15)
Issuance of treasury stock under employee stock plans	73		3	70	0	0
Issuance of treasury stock under employee stock plans, shares		2,688
Tax benefit from share-based compensation plans	44		44	0	0	0
Stock repurchases under stock repurchase programs	(100)		0	(100)	0	0
Stock repurchases under stock repurchase programs, shares	(1,700)	(1,694)
Cash dividends declared	(50)					(50)
Share-based compensation expense	49		49	0	0	0
Ending Balance at Oct. 31, 2012	$ 2,745		$ 3,114	$ (4,941)	$ 29	$ 4,543
Ending Balance, shares at Oct. 31, 2012		296,283