Note 14. 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. 29, 2012	Aug. 19, 2011	Feb. 28, 2011	Feb. 29, 2012	Feb. 28, 2011
Net export sales	$ 4,440	$ 2,907	$ 3,354	$ 9,005	$ 11,144
Europe [Member]
Net export sales	1,712	964	1,374	3,893	4,757
Other Geographic Area [Member]
Net export sales	860	526	453	1,493	1,583
United States [Member]
Net export sales	$ 1,868	$ 1,417	$ 1,527	$ 3,619	$ 4,804