Quarterly Consolidated Financial Information (Unaudited) - Schedule of Unaudited Quarterly Financial Data of Company (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Feb. 28, 2017	Nov. 30, 2016	Aug. 31, 2016	May 31, 2016	Feb. 28, 2016	Nov. 30, 2015	Aug. 31, 2015	May 31, 2015	Feb. 28, 2017	Feb. 29, 2016	Feb. 28, 2015
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 86,572	$ 88,660	$ 91,246	$ 90,410	$ 91,206	$ 97,516	$ 100,455	$ 96,769	$ 356,888	$ 385,946	$ 380,379
Gross profit margin	24,926	25,292	27,038	26,694	25,264	29,719	31,363	29,964	103,950	116,310	115,071
Net earnings	7,210	5,740	6,784	6,683	5,289	8,595	9,611	8,763	1,780	35,736	(44,533)
Dividends paid	$ 4,476	$ 4,537	$ 43,657	$ 4,530	$ 4,516	$ 4,516	$ 4,516	$ 4,496	$ 57,200	$ 18,044	$ 18,191
Per share of common stock:
Basic net earnings	$ 0.28	$ 0.22	$ 0.26	$ 0.26	$ 0.21	$ 0.34	$ 0.37	$ 0.34	$ 0.07	$ 1.39	$ (1.72)
Diluted net earnings	0.28	0.22	0.26	0.26	0.21	0.33	0.37	0.34	0.07	1.39	(1.72)
Dividends	$ 0.175	$ 0.175	$ 1.675	$ 0.175	$ 0.175	$ 0.175	$ 0.175	$ 0.175	$ 2.20	$ 0.70	$ 0.70