Segment Information And Major Customers - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jan. 26, 2013	Jan. 28, 2012	Jan. 26, 2013	Jan. 28, 2012	Jul. 28, 2012
Segment Reporting Information [Line Items]
Entity-Wide Disclosure on Geographic Areas, Basis for Attributing Revenue to Countries			three
Revenue, Net	$ 12,098,000,000	$ 11,527,000,000	$ 23,974,000,000	$ 22,783,000,000
United States [Member]
Segment Reporting Information [Line Items]
Cash, Cash Equivalents, and Short-term Investments	7,000,000,000		7,000,000,000		6,200,000,000
Revenue, Net	6,100,000,000	5,600,000,000	12,200,000,000	11,200,000,000
International [Member]
Segment Reporting Information [Line Items]
Cash, Cash Equivalents, and Short-term Investments	$ 39,400,000,000		$ 39,400,000,000		$ 42,500,000,000