CONSOLIDATED STATEMENTS OF EARNINGS (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2013	Nov. 30, 2012
Income Statement [Abstract]
Net sales	$ 136,550	$ 128,996	$ 410,304	$ 409,868
Cost of goods sold	98,791	98,385	300,091	317,059
Gross profit margin	37,759	30,611	110,213	92,809
Selling, general and administrative	22,340	20,591	65,628	63,948
(Gain) loss from disposal of assets	(15)	3	(270)	(6)
Income from operations	15,434	10,017	44,855	28,867
Other income (expense)
Interest expense	(342)	(335)	(809)	(1,206)
Other, net	(253)	(182)	(149)	(97)
Total other expense	(595)	(517)	(958)	(1,303)
Earnings before income taxes	14,839	9,500	43,897	27,564
Provision for income taxes	5,490	3,330	16,241	9,923
Net earnings	$ 9,349	$ 6,170	$ 27,656	$ 17,641
Weighted average common shares outstanding
Basic	26,126,437	26,025,072	26,107,307	26,011,692
Diluted	26,156,861	26,045,883	26,129,849	26,031,738
Per share amounts
Net earnings - basic	$ 0.36	$ 0.24	$ 1.06	$ 0.68
Net earnings - diluted	$ 0.36	$ 0.24	$ 1.06	$ 0.68
Cash dividends per share	$ 0.175	$ 0.175	$ 0.350	$ 0.525