Note 11 - Quarterly Consolidated Financial Information (unaudited) - Summary of Unaudited Quarterly Results of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	May 29, 2016	Feb. 28, 2016	Nov. 29, 2015	Aug. 30, 2015	May 31, 2015	Mar. 01, 2015	Nov. 30, 2014	Aug. 31, 2014	May 25, 2014	Feb. 23, 2014	Nov. 24, 2013	Aug. 25, 2013	May 29, 2016	May 31, 2015	May 25, 2014
Revenue	$ 135,313	$ 129,990	$ 140,441	$ 135,355	$ 134,448	$ 138,530	$ 132,665	$ 133,614	$ 120,929	$ 126,379	$ 120,026	$ 109,479	$ 541,099	$ 539,257	$ 476,813
Gross profit	22,784	12,931	17,265	17,977	18,668	16,885	15,666	14,188	16,143	20,155	13,734	12,532	70,957	65,407	62,564
Net income (loss)	$ 4,729	$ (21,190)	$ 1,868	$ 2,952	$ 4,196	$ 3,772	$ 3,223	$ 2,353	$ 4,542	$ 6,400	$ 3,451	$ 4,752	$ (11,641)	$ 13,544	$ 19,145
Net income (loss) per basic share (in dollars per share)	$ 0.17	$ (0.78)	$ 0.07	$ 0.11	$ 0.16	$ 0.14	$ 0.12	$ 0.09	$ 0.17	$ 0.24	$ 0.13	$ 0.18	$ (0.43)	$ 0.50	$ 0.72
Diluted net (loss) income per share (in dollars per share)	$ 0.17	$ (0.78)	$ 0.07	$ 0.11	$ 0.15	$ 0.14	$ 0.12	$ 0.09	$ 0.17	$ 0.24	$ 0.13	$ 0.18	$ (0.43)	$ 0.50	$ 0.71