Net Sales of Domestic and Foreign Units (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Feb. 28, 2013	Nov. 30, 2012	Aug. 31, 2012	May 31, 2012	Feb. 29, 2012	Nov. 30, 2011	Aug. 31, 2011	May 31, 2011	Feb. 28, 2013	Feb. 29, 2012	Feb. 28, 2011
Segment Reporting Information [Line Items]
Net Sales	$ 25,859	$ 30,387	$ 29,927	$ 34,834	$ 32,272	$ 34,009	$ 34,417	$ 36,036	$ 121,007	$ 136,734	$ 137,624
Domestic Net Sales
Segment Reporting Information [Line Items]
Net Sales									105,513	121,684	125,179
Foreign Net Sales
Segment Reporting Information [Line Items]
Net Sales									$ 15,494	$ 15,050	$ 12,445