Note 5 - Diluted Net Income Per Share - Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Aug. 26, 2018	Aug. 27, 2017
Numerator:
Net income applicable to common stockholders	$ 190	$ 2,146
Denominator:
Weighted average shares for basic net income per share (in shares)	27,738	27,506
Effect of dilutive securities:
Stock options and RSUs (in shares)	282	352
Weighted average shares for diluted net income per share (in shares)	28,020	27,858
Diluted net income per share (in dollars per share)	$ 0.01	$ 0.08