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. 29, 2016	Nov. 30, 2015	Aug. 31, 2015	May. 31, 2015	Feb. 28, 2015	Nov. 30, 2014	Aug. 31, 2014	May. 31, 2014	Feb. 29, 2016	Feb. 28, 2015	Feb. 28, 2014
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 128,185	$ 139,451	$ 150,761	$ 150,576	$ 140,242	$ 146,971	$ 151,841	$ 141,186	$ 568,973	$ 580,240	$ 542,442
Gross profit margin	33,991	40,574	40,630	37,544	35,384	36,516	38,188	35,388	152,739	145,476	143,793
Net earnings (loss)	4,845	10,674	11,046	9,171	8,598	(71,179)	10,016	8,032	35,736	(44,533)	13,189
Dividends paid	$ 4,516	$ 4,516	$ 4,516	$ 4,496	$ 4,502	$ 4,548	$ 4,574	$ 4,567	$ 18,044	$ 18,191	$ 13,765
Per share of common stock:
Basic net earnings (loss)	$ 0.19	$ 0.42	$ 0.43	$ 0.36	$ 0.34	$ (2.76)	$ 0.39	$ 0.31	$ 1.39	$ (1.72)	$ 0.50
Diluted net earnings (loss)	0.19	0.41	0.43	0.36	0.34	(2.76)	0.39	0.31	1.39	(1.72)	0.50
Dividends	$ 0.175	$ 0.175	$ 0.175	$ 0.175	$ 0.175	$ 0.175	$ 0.175	$ 0.175	$ 0.700	$ 0.700	$ 0.525