Note 1 - Organization, Basis of Presentation, and Summary of Significant Accounting Policies - Summary of Stock-based Compensation by Income Statement Line Item (Details) - USD ($) $ in Thousands	12 Months Ended
	May 29, 2016	May 31, 2015	May 25, 2014
Employee Stock Option [Member]
Stock-based compensation expense	$ 1,352	$ 561	$ 558
Restricted Stock Units (RSUs) [Member]
Stock-based compensation expense	2,113	1,016	798
Research and Development Expense [Member]
Stock-based compensation expense	241	38	39
Selling, General and Administrative Expenses [Member]
Stock-based compensation expense	3,224	1,539	1,317
Stock-based compensation expense	$ 3,465	$ 1,577	$ 1,356