Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net income	$ 3,498,714	$ 2,795,249
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,289,531	1,175,267
Deferred income taxes	31,025	126,454
Stock based compensation	275,540	330,823
Provision for bad debts	6,134	35,145
Provision for slow moving and obsolete inventory	(39,903)	9,814
Other operating non-cash items	(897)	(6,436)
Changes in assets and liabilities:
Trade accounts receivable	(1,479,704)	(729,936)
Receivables due from affiliated companies	83,836	538,375
Inventories	2,570,645	(3,021,201)
Prepaid expenses and other current assets	75,619	2,572
Accounts payable - trade	(424,845)	(334,890)
Accrued expenses payable	106,033	296,843
Net cash provided by operating activities	5,991,728	1,218,079
Cash flows from investing activities:
Purchases of property, plant and equipment	(718,474)	(1,358,776)
Purchase of intangible assets	(75,000)	(376,722)
Net cash used in investing activities	(793,474)	(1,735,498)
Cash flows from financing activities:
Payments on long-term debt	(448,442)	(332,185)
Borrowings on revolving line of credit	1,000,000	2,750,000
Repayments on revolving line of credit	(1,000,000)	(2,750,000)
Payments for taxes related to net share settlements of stock awards	(20,949)	(25,794)
Dividends paid to common shareholders	(468,306)	(555,275)
Proceeds from exercise of stock options	13,799
Net cash used in financing activities	(923,898)	(913,254)
Effect of exchange rate on cash	2,140	(1,247)
Net increase (decrease) in cash and restricted cash	4,276,496	(1,431,920)
Cash and restricted cash at beginning of period	3,733,924	5,165,844
Cash and restricted cash at end of period	8,010,420	3,733,924
Supplemental disclosure of cash flow information:
Cash paid for interest during period	156,623	136,031
Cash paid for income taxes during period	778,009	660,000
Operating lease right to use asset exchanged for operating lease liability	432,466
Finance lease right to use assets exchanged for finance lease liabilities	44,979
Cash paid under operating lease	94,800	94,800
Cash	6,125,322	1,401,047
Restricted cash	1,885,098	2,332,877
Total cash and restricted cash	8,010,420	3,733,924
Noncash investing and financing activities:
Issuance of note payable for asset acquisition	100,000	1,000,000
Imputed interest	(2,988)	(69,472)
Principal portion of note payable issued for asset acquisition	$ 97,012	$ 930,528