Income Taxes (Components Of Deferred Tax Assets And Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Jul. 26, 2014	Jul. 27, 2013
Income Tax Disclosure [Abstract]
Allowance for doubtful accounts and returns	$ 464	$ 390
Sales-type and direct-financing leases	231	167
Inventory write-downs and capitalization	307	216
Investment provisions	212	214
IPR&D, goodwill, and purchased intangible assets	135	123
Deferred revenue	1,689	1,624
Credits and net operating loss carryforwards	796	681
Share-based compensation expense	661	783
Accrued compensation	496	486
Other	676	560
Gross deferred tax assets	5,667	5,244
Valuation allowance	(114)	(98)
Total deferred tax assets	5,553	5,146
Purchased intangible assets	(1,229)	(1,101)
Depreciation	(48)	(169)
Unrealized gains on investments	(245)	(211)
Other	(26)	(23)
Total deferred tax liabilities	(1,548)	(1,504)
Total net deferred tax assets	$ 4,005	$ 3,642