Condensed Consolidated Statements of Earnings - USD ($)	3 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Net sales	$ 23,968,569	$ 27,904,521
Costs and expenses
Costs of goods sold	21,826,676	26,862,460
General, selling and administrative costs	1,353,456	1,134,576
Costs and Expenses, Total	23,180,132	27,997,036
Interest and other income	(17,250)	(15,252)
Earnings (loss) before income taxes	805,687	(77,263)
Income tax provision (benefit):
Current	244,160	78,435
Deferred	35,578	(37,448)
Income Tax Expense (Benefit), Total	279,738	40,987
Net earnings (loss)	$ 525,949	$ (118,250)
Average number of common shares outstanding:
Basic	6,799,444	6,799,444
Diluted	6,799,444	6,799,444
Net earnings (loss) per share:
Basic	$ 0.08	$ (0.02)
Diluted	0.08	(0.02)
Cash dividends declared per common share	$ 0.01	$ 0.02