Consolidated Statements of Earnings (Unaudited) (USD $) In Thousands, except Share data	3 Months Ended		6 Months Ended
	Aug. 31, 2011	Aug. 31, 2010	Aug. 31, 2011	Aug. 31, 2010
Consolidated Statements of Earnings [Abstract]
Net sales	$ 130,384	$ 143,034	$ 273,642	$ 283,775
Cost of goods sold	96,290	103,326	199,847	201,887
Gross profit margin	34,094	39,708	73,795	81,888
Selling, general and administrative	18,447	20,276	39,304	41,523
Gain from disposal of assets	(125)		(125)
Income from operations	15,772	19,432	34,616	40,365
Other income (expense)
Interest expense	(664)	(321)	(1,482)	(758)
Other, net	171	(11)	(5)	29
Total other income (expense)	(493)	(332)	(1,487)	(729)
Earnings before income taxes	15,279	19,100	33,129	39,636
Provision for income taxes	5,567	6,971	11,993	14,467
Net earnings	$ 9,712	$ 12,129	$ 21,136	$ 25,169
Weighted average common shares outstanding
Basic	25,933,902	25,840,376	25,914,986	25,820,626
Diluted	25,961,171	25,883,449	25,943,361	25,866,869
Per share amounts
Net earnings - basic	$ 0.37	$ 0.47	$ 0.82	$ 0.97
Net earnings - diluted	$ 0.37	$ 0.47	$ 0.81	$ 0.97
Cash dividends per share	$ 0.155	$ 0.155	$ 0.310	$ 0.310