Note 1 - Organization, Basis of Presentation, and Summary of Significant Accounting Policies - Revenue Arrangements (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 28, 2016	Mar. 01, 2015	Feb. 28, 2016	Mar. 01, 2015
Revenue Recorded Upon Shipment [Member]
Revenue	$ 118,789	$ 128,502	$ 341,914	$ 344,506
Revenue Recorded Upon Acceptance in Foreign Port [Member]
Revenue	6,389	8,086	50,873	56,779
Revenue from License Fees, R&D Contracts and Royalties/Profit Sharing [Member]
Revenue	787	153	3,327	788
Revenue from Multiple Element Arrangements [Member]
Revenue	4,025	1,789	9,672	2,736
Revenue	$ 129,990	$ 138,530	$ 405,786	$ 404,809