Accounts Receivable - Allowance for Returns and Allowances and Discounts (Detail) - USD ($) $ in Thousands		12 Months Ended
		May 03, 2020	Apr. 28, 2019	Apr. 29, 2018
Valuation and Qualifying Accounts Disclosure [Line Items]
adoption of ASC Topic 606	[1]	$ 119	$ 88	$ 118
Reserve for returns and allowances and discounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
beginning balance		(226)	(1,433)	(1,220)
provision for returns and allowances and discounts		(1,603)	(2,180)	(3,295)
credits issued and discounts taken		1,745	2,242	3,082
ending balance		$ (84)	(226)	$ (1,433)
Reserve for returns and allowances and discounts [Member] | Adjustments Due to ASC 606 Adoption [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
adoption of ASC Topic 606			$ 1,145

[1] Amounts pertain to a change in estimate of the recoverability of certain U.S. state loss carryforward balances as of the end of the respective prior fiscal year.