Segment Information and Major Customers (Summary Of Reportable Segments) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jan. 24, 2015	Jan. 25, 2014	Jan. 24, 2015	Jan. 25, 2014
Segment Reporting Information [Line Items]
Revenue	$ 11,936	$ 11,155	$ 24,181	$ 23,240
Gross margin	7,090	5,951	14,423	13,358
Unallocated corporate items
Segment Reporting Information [Line Items]
Gross margin	(278)	(889)	(695)	(1,099)
Americas
Segment Reporting Information [Line Items]
Revenue	7,101	6,460	14,602	13,776
Gross margin	4,406	3,977	9,216	8,627
EMEA
Segment Reporting Information [Line Items]
Revenue	3,091	2,896	6,093	5,829
Gross margin	1,910	1,870	3,825	3,758
APJC
Segment Reporting Information [Line Items]
Revenue	1,744	1,799	3,486	3,635
Gross margin	1,052	993	2,077	2,072
Segment total
Segment Reporting Information [Line Items]
Gross margin	$ 7,368	$ 6,840	$ 15,118	$ 14,457