CONSOLIDATED STATEMENTS OF EARNINGS (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Aug. 31, 2014	Aug. 31, 2013	Aug. 31, 2014	Aug. 31, 2013
Income Statement [Abstract]
Net sales	$ 151,841	$ 135,288	$ 293,027	$ 273,754
Cost of goods sold	113,653	98,629	219,451	201,300
Gross profit margin	38,188	36,659	73,576	72,454
Selling, general and administrative	21,824	21,083	43,619	43,288
Gain from disposal of assets	(3)	(248)	(4)	(255)
Income from operations	16,367	15,824	29,961	29,421
Other income (expense)
Interest expense	(525)	(216)	(1,027)	(467)
Other, net	57	(53)	(286)	104
Total other expense	(468)	(269)	(1,313)	(363)
Earnings before income taxes	15,899	15,555	28,648	29,058
Provision for income taxes	5,883	5,754	10,600	10,751
Net earnings	$ 10,016	$ 9,801	$ 18,048	$ 18,307
Weighted average common shares outstanding
Basic	25,990,496	26,102,129	25,991,444	26,078,188
Diluted	26,002,701	26,128,655	26,004,549	26,098,420
Per share amounts
Net earnings - basic	$ 0.39	$ 0.38	$ 0.69	$ 0.70
Net earnings - diluted	$ 0.39	$ 0.38	$ 0.69	$ 0.70
Cash dividends per share	$ 0.175	$ 0.175	$ 0.350	$ 0.175