Segment Information and Major Customers - Long-lived Assets by Geographic Areas (Details) - USD ($) $ in Millions	Jul. 25, 2020	Jul. 27, 2019	Jul. 28, 2018
Segment Reporting, Asset Reconciling Item [Line Items]
Long-lived assets	$ 3,374	$ 2,789	$ 3,006
United States
Segment Reporting, Asset Reconciling Item [Line Items]
Long-lived assets	2,328	2,266	2,487
International
Segment Reporting, Asset Reconciling Item [Line Items]
Long-lived assets	$ 1,046	$ 523	$ 519

Long-lived assets other than financial instruments, long-term customer relationships of a financial institution, mortgage and other servicing rights, deferred policy acquisition costs, and deferred tax assets.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 41
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9038-108599

Name:	us-gaap_NoncurrentAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant