Condensed Consolidated Statements of Earnings (Unaudited) (USD $)	3 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Condensed Consolidated Statements of Earning (Loss)[Abstract]
Net Sales	$ 38,935,456	$ 29,222,232
Costs and expenses
Costs of goods sold	34,778,631	25,784,294
General, selling and administrative costs	1,419,819	1,274,470
Total costs and expenses	36,198,450	27,058,764
Interest and other income	(17,872)	(14,027)
Earnings before income taxes	2,754,878	2,177,495
Income tax provision (benefit):
Current	946,142	755,958
Deferred	(22,675)	(13,600)
Total income tax provision (benefit)	923,467	742,358
Net earnings	$ 1,831,411	$ 1,435,137
Average number of common shares outstanding:
Basic	6,799,444	6,799,444
Diluted	6,799,444	6,799,444
Net earnings per share:
Basic	$ 0.27	$ 0.21
Diluted	$ 0.27	$ 0.21
Cash dividends declared per common share	$ 0.13	$ 0.04