Note 5 - Derivative Financial Instruments (Details Textual) - USD ($)	Oct. 28, 2017	Apr. 29, 2017
Derivative, Notional Amount	$ 42,600,000
Price Risk Cash Flow Hedge Unrealized Gain (Loss) to be Reclassified During Next 12 Months	3,100,000
Prepaid Expenses and Other Current Assets [Member]
Derivative Asset, Current	3,100,000	$ 602,000
Other Noncurrent Assets [Member]
Derivative Asset, Noncurrent	$ 308,000
Accrued Liabilities1 [Member]
Derivative Liability, Current		848,000
Other Liabilities [Member]
Derivative Liability, Noncurrent		$ 476,000