Note 5 - Derivative Financial Instruments (Details Textual) - USD ($)	Jan. 27, 2018	Apr. 29, 2017
Derivative, Notional Amount	$ 33,600,000
Price Risk Cash Flow Hedge Unrealized Gain (Loss) to be Reclassified During Next 12 Months	4,700,000
Derivative Asset, Current	$ 4,700,000
Prepaid Expenses and Other Current Assets [Member]
Derivative Asset, Current		$ 602,000
Accrued Liabilities1 [Member]
Derivative Liability, Current		848,000
Other Liabilities [Member]
Derivative Liability, Noncurrent		$ 476,000