Derivatives and Currency Exchange Risk Management - (Gains) Losses Recognized in AOCI, Net Investment Hedges (Details) - USD ($) $ in Millions	3 Months Ended
Jul. 31, 2020	Jul. 26, 2019
Derivative Instruments, (Gain) Loss [Line Items]
Recognized in AOCI, Net investment hedges	$ 1,112	$ (99)
Currency exchange rate contracts \| Net investment hedges
Derivative Instruments, (Gain) Loss [Line Items]
Recognized in AOCI, Net investment hedges	$ 1,112	$ (99)

Amount, after tax and adjustments, of gain (loss) from increase (decrease) in value of excluded component of derivative designated and qualifying as hedge. Adjustments include, but are not limited to, reclassifications for sale and settlement, and amounts recognized under systematic and rational method.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (bb)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (dd)
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669646-108580

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