Gift Cards - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Jan. 27, 2018	Jan. 28, 2017	Jan. 27, 2018	Jan. 28, 2017	Apr. 29, 2017
Gift Cards [Line Items]
Gift card breakage	$ 27,496	$ 20,805	$ 37,224	$ 30,561
Gift card liabilities	$ 358,609	$ 384,830	$ 358,609	$ 384,830	$ 351,424

Carrying value as of the balance sheet date of the liability for outstanding gift cards. Retail customers purchase gift cards or gift certificates that can be redeemed at a later date for merchandise or services; those unredeemed represent a liability of the entity because the revenue is being deferred.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.20)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_AccruedLiabilitiesForUnredeeemedGiftCards
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant