Business Combinations (Summary Of Allocation Of Total Purchase Consideration) (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jan. 26, 2013
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	$ 1,207
Business Acquisition, Purchase Price Allocation, Goodwill Amount	920
Business Acquisition, Purchase Price Allocation, Liabilities Assumed	(74)
Business Acquisition, Purchase Price Allocation, Intangible Assets Other than Goodwill	361
Meraki, Inc. [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	974
Business Acquisition, Purchase Price Allocation, Goodwill Amount	744
Business Acquisition, Purchase Price Allocation, Liabilities Assumed	(59)
Business Acquisition, Purchase Price Allocation, Intangible Assets Other than Goodwill	289
NDS Group Limited [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Cash Paid	4,012
Repayments of Assumed Debt	993
Business Combination, Consideration Transferred	5,005
Business Acquisition, Purchase Price Allocation, Current Assets, Cash and Cash Equivalents	98
Business Acquisition, Purchase Price Allocation, Current Assets, Receivables	199
Business Acquisition, Purchase Price Allocation, Tangible Assets	268
Business Acquisition, Purchase Price Allocation, Goodwill Amount	3,444
Business Acquisition, Purchase Price Allocation, Deferred Income Taxes, Asset (Liability), Net	(378)
Business Acquisition, Purchase Price Allocation, Liabilities Assumed	(372)
Business Acquisition, Purchase Price Allocation, Intangible Assets Other than Goodwill	1,746
Other Acquisition [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	233
Business Acquisition, Purchase Price Allocation, Goodwill Amount	176
Business Acquisition, Purchase Price Allocation, Liabilities Assumed	(15)
Business Acquisition, Purchase Price Allocation, Intangible Assets Other than Goodwill	$ 72