Description of Business and Significant Accounting Policies - Additional Information (Detail) $ in Millions	3 Months Ended
Jul. 27, 2018 USD ($)
ASU 2016-16
Description Of Business And Significant Accounting Policies [Line Items]
Cumulative-effect adjustment to decrease retained earnings	$ (51)

Amount of the related income tax effect of a cumulative effect on retained earnings.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22663-107794

Name:	us-gaap_CumulativeEffectOnRetainedEarningsTax1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration