Income Taxes (Components Of Deferred Tax Assets And Liabilities) (Detail) (USD $) In Millions, unless otherwise specified	Jul. 27, 2013	Jul. 28, 2012
Income Taxes
Allowance for doubtful accounts and returns	$ 390	$ 433
Sales-type and direct-financing leases	167	162
Inventory write-downs and capitalization	216	127
Deferred Tax Assets, Investments	214	261
IPR&D, goodwill, and purchased intangible assets	123	119
Deferred revenue	1,624	1,618
Credits and net operating loss carryforwards	681	721
Share-based compensation expense	783	1,059
Accrued compensation	486	481
Other	560	583
Gross deferred tax assets	5,244	5,564
Valuation allowance	(98)	(60)
Total deferred tax assets	5,146	5,504
Purchased intangible assets	(1,101)	(809)
Deferred Tax Assets, Property, Plant and Equipment	(169)	(131)
Deferred Tax Liabilities, Investments	(211)	(222)
Other	(23)	(34)
Total deferred tax liabilities	(1,504)	(1,196)
Total net deferred tax assets	$ 3,642	$ 4,308