Stockholders' Equity - Schedule of Employee Stock Purchase Plan (ESPP) (Detail) - USD ($) shares in Millions, $ in Millions	3 Months Ended
Jul. 26, 2019	Jul. 27, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued under the ESPP	1	2
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from issuance of shares	$ 54	$ 49

Number of shares issued during the period as a result of an employee stock purchase plan.

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Name:	us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration