Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Operating activities:
Net income	$ 5,513,608	$ 4,598,350
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation	2,181,060	2,011,675
Amortization	1,251,662	1,217,525
Stock compensation expense	968,467	869,055
Deferred income taxes	162,637	396,233
Non-cash lease expense	19,222
Provision for doubtful accounts	290,128	156,000
Changes in operating assets and liabilities
Accounts receivable	(784,562)	651,988
Inventories	2,089,861	(1,580,151)
Prepaid expenses and other current assets	666,070	573,604
Accounts payable	(1,525,060)	(3,066,106)
Other accrued liabilities	3,869,138	(1,352,904)
Total adjustments	9,188,623	(123,081)
Net cash provided by operating activities	14,702,231	4,475,269
Investing activities:
Purchase of property, plant and equipment	(1,680,479)	(2,850,993)
Purchase of intellectual property		(379,921)
Net cash used by investing activities	(1,680,479)	(3,230,914)
Financing activities:
Net repayments of long-term debt	(7,042,708)	(3,167,233)
Repayments on mortgage	(266,667)	(266,667)
Distributions to shareholders	(1,608,956)	(1,484,829)
Cash settlement of stock options	(1,687,782)	(768,075)
Purchase of treasury stock		(365,149)
Net cash used by financing activities	(10,606,113)	(6,051,953)
Effect of exchange rate changes	(2,799)	(121,629)
Net increase (decrease) in cash and cash equivalents	2,412,841	(4,929,227)
Cash and cash equivalents at beginning of year	4,409,042	9,338,269
Cash and cash equivalents at end of year	6,821,883	4,409,042
Supplemental cash flow information:
Cash paid for income taxes	422,339	887,592
Cash paid for interest expense	$ 1,863,961	$ 1,855,356