Condensed Consolidated Statements of Operations - Unaudited - USD ($)	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Net sales	$ 28,033,521	$ 15,988,745	$ 77,194,500	$ 56,700,015
Costs and expenses
Costs of goods sold	26,364,387	15,417,174	72,884,773	57,427,143
General, selling and administrative costs	999,220	957,305	2,962,139	2,965,884
Interest expense	8,451		8,451
Costs and expenses, total	27,372,058	16,374,479	75,855,363	60,393,027
Interest and other income	(4,375)	(14,755)	(13,125)	(44,255)
Earnings (loss) before income taxes	665,838	(370,979)	1,352,262	(3,648,757)
Provision for (benefit from) income taxes:
Current	46,452		46,452	(673,618)
Deferred	496,457	(134,354)	702,222	(673,413)
Income tax	542,909	(134,354)	748,674	(1,347,031)
Net earnings (loss)	$ 122,929	$ (236,625)	$ 603,588	$ (2,301,726)
Weighted average number of common shares outstanding:
Basic (in shares)	7,009,444	6,799,444	7,009,444	6,799,444
Diluted (in shares)	7,009,444	6,799,444	7,009,444	6,799,444
Net earnings (loss) per share:
Basic (in dollars per share)	$ 0.02	$ (0.03)	$ 0.09	$ (0.34)
Diluted (in dollars per share)	0.02	(0.03)	0.09	(0.34)
Cash dividends declared per common share (in dollars per share)	$ 0.01	$ 0.01	$ 0.03	$ 0.03