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	9 Months Ended
	Feb. 28, 2013	Feb. 29, 2012	Aug. 19, 2011	Feb. 29, 2012	Feb. 28, 2013
Net export sales	$ 5,625	$ 4,440	$ 2,907	$ 9,005	$ 16,645
United States [Member]
Net export sales	2,737	1,868	1,417	3,619	8,625
Europe [Member]
Net export sales	2,225	1,712	964	3,893	5,717
Other Geographic Area [Member]
Net export sales	$ 663	$ 860	$ 526	$ 1,493	$ 2,303