Stockholders' Equity - Number and Value of Shares Netted for Employee Taxes (Detail) - Restricted Stock Units - USD ($) shares in Millions, $ in Millions	6 Months Ended
Oct. 25, 2019	Oct. 26, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares withheld for taxes	1	1
Fair value of shares withheld	$ 74	$ 89

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration