Cash, Cash Equivalents and Investments (Gains and Losses on Investments) (Details) - USD ($) $ in Millions	12 Months Ended
Oct. 25, 2020	Oct. 27, 2019	Oct. 28, 2018
Gains and Losses on Investments
Gross realized gains	$ 19	$ 10	$ 29
Gross realized losses	$ 2	$ 2	$ 3

Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27357-111563

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