Commitments and Contingencies (Additional Information) (Details) - USD ($) $ in Millions	3 Months Ended				12 Months Ended			24 Months Ended
	Apr. 25, 2015	Jan. 25, 2014	Oct. 26, 2013	Apr. 28, 2012	Jul. 25, 2015	Jul. 26, 2014	Jul. 27, 2013	Jul. 25, 2015
Site Contingency [Line Items]
Rent expense					$ 394	$ 413	$ 416
Purchase Commitments					4,078	4,169		$ 4,078
Liability for purchase commitments					156	$ 162		156
Future compensation expense & contingent consideration					$ 296			$ 296
Commitments and contingencies
Volume of channel partner financing					$ 25,900	$ 24,600	23,800
Balance of the channel partner financing subject to guarantees					1,200	1,200		$ 1,200
Financing provided by third parties for leases and loans related to End Users on which the Company has provided guarantees					107	129	185
Cost of Goods Sold					15,377	15,641	$ 15,541
Brazilian Authority Claim Of Import Tax Evasion By Importer Tax Portion					262			262
Brazilian Authority Claim Of Import Tax Evasion By Importer Interest Portion					1,100			1,100
Brazilian Authority Claim Of Import Tax Evasion By Importer Penalties Portion					$ 1,200			1,200
Minimum
Site Contingency [Line Items]
Warranty period for products, in days					90 days
Channel partners revolving short-term financing payment term					60 days
Maximum
Site Contingency [Line Items]
Warranty period for products, in years					5 years
Channel partners revolving short-term financing payment term					90 days
End User Lease And Loan Term					3 years
Insieme Networks Inc
Site Contingency [Line Items]
Initial Funding				$ 100
Ownership percentage as a result of investment			83.00%
Labor and Related Expense					$ 207	416		623
Insieme Networks Inc | Maximum
Site Contingency [Line Items]
Commitments and contingencies					843			843
Investments In Privately Held Companies [Member]
Site Contingency [Line Items]
Commitments and contingencies					205	255		205
Supplier Component Remediation Liability
Site Contingency [Line Items]
Commitments and contingencies			$ 63		$ 408	$ 670		$ 408
Cost of Goods Sold	$ (164)	$ 655
Russia and the Commonwealth of Independent States [Member]
Site Contingency [Line Items]
Percentage of revenue, Percentage					2.00%