Commitments and Contingencies (Additional Information) (Details) - USD ($) $ in Millions	3 Months Ended					27 Months Ended
	Oct. 24, 2015	Apr. 25, 2015	Oct. 25, 2014	Jan. 25, 2014	Apr. 28, 2012	Oct. 24, 2015	Jul. 25, 2015
Contingency [Line Items]
Purchase Commitments	$ 4,028					$ 4,028	$ 4,078
Liability for purchase commitments	178					178	$ 156
Future compensation expense & contingent consideration, maximum	$ 253					$ 253
Commitments and contingencies
Volume of channel partner financing	$ 6,900		$ 6,300
Balance of the channel partner financing subject to guarantees	1,200					$ 1,200	$ 1,200
Financing provided by third parties for leases and loans on which the Company has provided guarantees	23		26
Cost of Goods Sold	3,853		$ 3,919
Brazilian Authority Claim Of Import Tax Evasion By Importer Tax Portion	222					222
Brazilian Authority Claim Of Import Tax Evasion By Importer Interest Portion	1,000					1,000
Brazilian Authority Claim Of Import Tax Evasion By Importer Penalties Portion	$ 1,000					1,000
Minimum
Contingency [Line Items]
Warranty period for products, in days	90 days
Channel partners revolving short-term financing payment term, in days	60 days
Maximum
Contingency [Line Items]
Warranty period for products, in years	5 years
Channel partners revolving short-term financing payment term, in days	90 days
End User Lease And Loan Term, in years	3 years
Insieme Networks Inc
Contingency [Line Items]
Variable Interest Entities Investment					$ 100
Ownership percentage as a result of investment			83.00%
Compensation expense related to acquisitions	$ 51		$ 53			674
Insieme Networks Inc | Partial First Milestone Payment [Member]
Contingency [Line Items]
Compensation expense related to acquisitions	291
Investments In Privately Held Companies
Contingency [Line Items]
Commitments and contingencies	192					192	205
Supplier Component Remediation Liability
Contingency [Line Items]
Commitments and contingencies	$ 391			$ 63		391	$ 408
Cost of Goods Sold		$ (164)		$ 655
Russia and the Commonwealth of Independent States [Member]
Contingency [Line Items]
Percentage of revenue, Percentage	2.00%
Including compensation that has been expensed through current reporting period [Member] | Insieme Networks Inc | Maximum
Contingency [Line Items]
Commitments and contingencies	$ 841					$ 841