Note 1 - Organization, Basis of Presentation, and Summary of Significant Accounting Policies - Revenue Arrangements (Details) - USD ($) $ in Thousands	3 Months Ended
	Aug. 30, 2015	Aug. 31, 2014
Revenue Recorded Upon Shipment [Member]
Revenue	$ 110,416	$ 106,240
Revenue Recorded Upon Acceptance in Foreign Port [Member]
Revenue	22,344	26,587
Revenue from License Fees, R&D Contracts and Royalties/Profit Sharing [Member]
Revenue	1,589	575
Revenue from Multiple Element Arrangements [Member]
Revenue	1,006	212
Revenue	$ 135,355	$ 133,614