Segment Information and Major Customers (Summary Of Reportable Segments) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jan. 28, 2017	Jan. 23, 2016	Jan. 28, 2017	Jan. 23, 2016
Segment Reporting Information [Line Items]
Revenue, total	$ 11,580	$ 11,927	$ 23,932	$ 24,609
Gross margin	7,276	7,432	15,160	15,264
Operating Segments \| Americas
Segment Reporting Information [Line Items]
Revenue, total	6,660	6,911	14,103	14,703
Gross margin	4,288	4,411	9,121	9,354
Operating Segments \| EMEA
Segment Reporting Information [Line Items]
Revenue, total	3,065	3,093	6,078	6,187
Gross margin	2,012	2,011	4,025	4,000
Operating Segments \| APJC
Segment Reporting Information [Line Items]
Revenue, total	1,855	1,923	3,751	3,719
Gross margin	1,121	1,184	2,325	2,262
Segment Reconciling Items
Segment Reporting Information [Line Items]
Gross margin	7,421	7,606	15,471	15,616
Intersegment Eliminations
Segment Reporting Information [Line Items]
Gross margin	$ (145)	$ (174)	$ (311)	$ (352)

Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1,2)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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