Note 5 - Property, Equipment, and Assets Held for Sale (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 28, 2017	Mar. 01, 2016	Feb. 28, 2017	Mar. 01, 2016	May 31, 2016
Disposal Group, Including Discontinued Operation, Assets, Current	$ 20,450		$ 20,450		$ 4,642
Property, Plant and Equipment, Disposals	7,500	$ 2,400	15,900	$ 5,200
Gain (Loss) on Disposition of Property Plant Equipment	2,300	100		1,000
Proceeds from Sale of Property Plant and Equipment, Net	$ 9,800	$ 2,500	$ 15,900	$ 6,200