Revenue (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended
Oct. 27, 2018	Oct. 28, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 13,072	$ 12,136
Product
Disaggregation of Revenue [Line Items]
Revenue	9,890	9,054
Infrastructure Platforms
Disaggregation of Revenue [Line Items]
Revenue	7,642	6,980
Applications
Disaggregation of Revenue [Line Items]
Revenue	1,419	1,203
Security
Disaggregation of Revenue [Line Items]
Revenue	651	585
Other Products
Disaggregation of Revenue [Line Items]
Revenue	178	286
Service
Disaggregation of Revenue [Line Items]
Revenue	$ 3,182	$ 3,082

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130543-203045

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130539-203045

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130545-203045

Name:	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration