Note 15 - Segment and Geographic Information (Detail) - Net Export Sales to Unaffiliated Customers (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Nov. 30, 2012	Nov. 30, 2011	Aug. 19, 2011	Nov. 30, 2011	Nov. 30, 2012
Net export sales	$ 5,189	$ 4,129	$ 2,907	$ 4,565	$ 11,020
United States [Member]
Net export sales	2,347	1,593	1,417	1,751	5,888
Europe [Member]
Net export sales	2,030	1,962	964	2,181	3,492
Other Geographic Area [Member]
Net export sales	$ 812	$ 574	$ 526	$ 633	$ 1,640