Derivatives - Schedule of Gains and Losses on Derivative Instruments (Detail) - Derivatives Designated as Hedging Instruments [Member] - EURO Foreign Exchange Contract [Member] - USD ($) $ in Thousands	12 Months Ended
	Apr. 29, 2018	Apr. 30, 2017	May 01, 2016
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amt of Gain (Loss) (net of tax) Recognized in OCI on Derivative (Effective Portion) and recorded in Accrued Expenses at Fair Value	$ (55)
Other Expense [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	0	$ 0	$ 0
Amount of Gain (loss) (net of tax) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	$ 0	$ 0	$ 0