CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Apr. 29, 2018	Apr. 30, 2017	May 01, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 20,877	$ 22,334	$ 16,935
Other comprehensive (loss) income
Loss on foreign currency cash flow hedge instrument, net of tax	(55)
Unrealized (losses) gains on investments
Unrealized holding (losses) gains on investments, net of tax	(26)	128	(176)
Reclassification adjustment for realized loss included in net income		12	127
Unrealized (losses) gains on investments, net	(26)	140	(49)
Total other comprehensive (loss) income	(81)	140	(49)
Comprehensive income	$ 20,796	$ 22,474	$ 16,886