Segment Information and Major Customers - Summary of Reportable Segments (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jan. 25, 2020	Jan. 26, 2019	Jan. 25, 2020	Jan. 26, 2019
Segment Reporting Information [Line Items]
Revenue, total	$ 12,005	$ 12,446	$ 25,164	$ 25,518
Gross margin	7,764	7,773	16,228	15,919
Americas
Segment Reporting Information [Line Items]
Revenue, total	7,013	7,352	14,990	15,103
EMEA
Segment Reporting Information [Line Items]
Revenue, total	3,134	3,223	6,417	6,447
APJC
Segment Reporting Information [Line Items]
Revenue, total	1,859	1,872	3,758	3,968
Operating segments
Segment Reporting Information [Line Items]
Gross margin	7,974	7,975	16,650	16,316
Operating segments \| Americas
Segment Reporting Information [Line Items]
Gross margin	4,692	4,796	10,008	9,866
Operating segments \| EMEA
Segment Reporting Information [Line Items]
Gross margin	2,062	2,070	4,229	4,141
Operating segments \| APJC
Segment Reporting Information [Line Items]
Gross margin	1,219	1,109	2,413	2,309
Unallocated corporate items
Segment Reporting Information [Line Items]
Gross margin	$ (210)	$ (202)	$ (422)	$ (397)

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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1,2)
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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
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-Name Accounting Standards Codification
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