Note 18. Segment and Geographic Information (Detail) - Net Export Sales to Unaffiliated Customers (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended	12 Months Ended
	Aug. 19, 2011	May 31, 2012	May 31, 2011	May 31, 2010
Net export sales	$ 2,907	$ 13,940	$ 14,978	$ 13,398
United States [Member]
Net export sales	1,417	5,426	6,100	5,378
Europe [Member]
Net export sales	964	5,806	6,609	5,947
Other Geographic Area [Member]
Net export sales	$ 526	$ 2,708	$ 2,269	$ 2,073