Summary of Changes in Contract Liabilities Related to Gift Card Program (Detail) $ in Thousands	3 Months Ended
	Jul. 31, 2018 USD ($)
Gift Cards [Line Items]
Gift card liability balance as of April 28, 2018	$ 323,465
Gift card breakage	(4,494)
Gift card redemptions	(55,020)
Gift card issuances	50,146
Gift card liability balance as of July 28, 2018	223,950
Calculated under Revenue Guidance in Effect before Topic 606 | ASU 2014-09
Gift Cards [Line Items]
Gift card liability balance as of April 28, 2018	323,465
Difference between Revenue Guidance in Effect before and after Topic 606 | ASU 2014-09
Gift Cards [Line Items]
Gift card liability balance as of April 28, 2018	$ (90,147)