Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 4,451,751	$ 6,402,259	$ 6,402,405
Adjustments to reconcile net income to net cash provided by operating activities -
Depreciation and amortization	1,875,102	1,719,154	1,567,172
Loss on disposal or abandonment of assets	3,139	16,985	31,064
Non-cash share-based compensation	239,599	199,870	145,322
Deferred income taxes	(215,576)	205,111	289,171
Foreign currency translation	883,670	(163,292)	(896,928)
Net changes in assets and liabilities, net of effect of business acquisitions:
Accounts receivable-trade	99,772	(7,778)	71,848
Inventory	(4,133,658)	407,000	(709,047)
Prepaid expenses	135,713	(284,788)	43,585
Other current assets	(48,797)	(70,035)	87,561
Accounts payable-trade	(208,434)	(361,492)	728,158
Accrued expenses and other liabilities	(983,710)	(108,365)	651,038
Income taxes	923,016	(415,046)	(212,449)
Total adjustments	(1,430,164)	1,137,324	1,796,495
Net cash provided by operating activities	3,021,587	7,539,583	8,198,900
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment	(1,689,645)	(1,697,704)	(2,164,040)
Purchase of intangible property			(10,000)
Proceeds from sale of assets / insurance	35,963	153,483	11,662
Decrease (increase) in other assets	(43,669)	(1,127)	295
Net cash used in investing activities	(1,697,351)	(1,545,348)	(2,162,083)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase (decrease) in revolving credit loans			(3,500,000)
Proceeds from notes payable and long-term debt		3,660,505	3,711,225
Payments on notes payable and long-term debt			(2,143,125)
Payments on capital lease obligations	(72,686)	(79,396)	(79,890)
Repurchase of common stock (treasury stock)		(3,675,654)	(3,708,862)
Proceeds from exercise of stock options	223,404	0	9,920
Net cash provided by (used in) financing activities	150,718	(94,545)	(5,710,732)
NET INCREASE (DECREASE) IN CASH	1,474,954	5,899,689	326,085
CASH, beginning of period	16,862,304	10,962,615	10,636,530
CASH, end of period	18,337,258	16,862,304	10,962,615
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Interest paid during the period	205,555	155,189	330,004
Income tax paid during the period, net of refunds	1,788,357	4,215,616	3,743,864
NON-CASH INVESTING ACTIVITIES
Equipment purchased via capital lease arrangements			$ 231,972