Note 10 - Commitments and Contingencies (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Apr. 30, 2016	May 02, 2015	May 03, 2014
Raw Material [Member]
Purchase Obligation, Due in Next Twelve Months	$ 45.5
Commitments for Plant and Equipment [Member]
Purchase Obligation, Due in Next Twelve Months	5.0
Operating Leases, Rent Expense	9.2	$ 8.2	$ 7.9
Leveraged Leases, Net Investment in Leveraged Leases Disclosure, Residual Value of Leased Assets	$ 4.4