Note 1 - Organization, Basis of Presentation, and Summary of Significant Accounting Policies - Revenue Arrangements (Details) - USD ($) $ in Thousands	12 Months Ended
	May. 31, 2015	May. 25, 2014	May. 26, 2013
Revenue Recorded Upon Shipment [Member]
Revenue	$ 465,484	$ 398,938	$ 359,518
Revenue Recorded Upon Acceptance in Foreign Port [Member]
Revenue	67,714	69,710	78,442
Revenue from License Fees, R&D Contracts and Royalties/Profit Sharing [Member]
Revenue	4,253	6,811	1,773
Revenue from Multiple Element Arrangements [Member]
Revenue	1,806	1,354	1,975
Revenue	$ 539,257	$ 476,813	$ 441,708