Condensed Consolidated Statements of Operations - Unaudited - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net sales	$ 23,165,705	$ 31,544,474	$ 47,134,273	$ 59,448,996
Costs and expenses
Costs of goods sold	22,258,002	29,123,545	44,084,677	55,986,005
General, selling and administrative costs	1,212,836	1,296,852	2,566,292	2,431,429
Costs and expenses, total	23,470,838	30,420,397	46,650,969	58,417,434
Interest and other income	(17,250)	(15,282)	(34,500)	(30,534)
Earnings (loss) before income taxes	(287,883)	1,139,359	517,804	1,062,096
Provision for (benefit from) income taxes:
Current	(130,167)	401,221	113,993	479,656
Deferred	35,578	(27,517)	71,156	(64,965)
Income tax expense (benefit), total	(94,589)	373,704	185,149	414,691
Net earnings (loss)	$ (193,294)	$ 765,655	$ 332,655	$ 647,405
Weighted average number of common shares outstanding:
Basic (in shares)	6,799,444	6,799,444	6,799,444	6,799,444
Diluted (in shares)	6,799,444	6,799,444	6,799,444	6,799,444
Net earnings (loss) per share:
Basic (in dollars per share)	$ (0.03)	$ 0.11	$ 0.05	$ 0.10
Diluted (in dollars per share)	(0.03)	0.11	0.05	0.10
Cash dividends declared per common share (in dollars per share)	$ 0.01	$ 0.02	$ 0.02	$ 0.04