Condensed Consolidated Statements of Income (Unaudited) (USD $)	12 Months Ended
	Feb. 28, 2013	Feb. 29, 2012	Feb. 28, 2011
Income Statement [Abstract]
Net Sales	$ 570,594,238	$ 469,112,410	$ 380,649,407
Costs and Expenses
Cost of Sales	406,421,677	344,525,516	273,006,712
Selling, General and Administrative	66,188,575	48,864,886	46,645,119
Interest Expense	13,072,605	13,939,149	7,730,556
Net Loss (Gain) On Sale of Property, Plant and Equipment, and Insurance Proceeds	(8,302,770)	166,183	(75,054)
Other Expense (Income) - net	(1,154,682)	(2,024,229)	(1,615,942)
Total costs and expenses	476,225,405	405,471,505	325,691,391
Income before income taxes	94,368,833	63,640,905	54,958,016
Income Tax Expense	33,912,627	22,905,109	19,995,375
Net Income	$ 60,456,206	$ 40,735,796	$ 34,962,641
Earnings Per Common Share
Basic Earnings Per Share (usd per share)	$ 2.39	$ 1.62	$ 1.40
Diluted Earnings Per Share (usd per share)	$ 2.37	$ 1.61	$ 1.39
Weighted average number common shares (shares)	25,320,147	25,131,754	24,922,700
Weighted average number common shares and potentially dilutive common shares (shares)	25,560,594	25,362,120	25,201,308