Consolidated Statements of Stockholders' Equity - USD ($)	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balance (in shares) at Dec. 31, 2014	10,210,939
Balance at Dec. 31, 2014	$ 26,890	$ 6,013,419	$ (2,894,068)	$ 46,664,829	$ (688,058)	$ 49,123,012
Shares issued - stock options exercised (in shares)	2,000					2,000
Shares issued - stock options exercised	$ 5	9,915				$ 9,920
Share-based compensation (in shares)	8,650
Share-based compensation	$ 21	145,301				145,322
Net income				6,402,405		6,402,405
Purchase of Treasury stock (in shares)	(528,725)
Purchase of Treasury stock			(3,708,862)			(3,708,862)
Translation adjustment					(999,621)	(999,621)
Balance (in shares) at Dec. 31, 2015	9,692,864
Balance at Dec. 31, 2015	$ 26,916	6,168,635	(6,602,930)	53,067,234	(1,687,679)	$ 50,972,176
Shares issued - stock options exercised (in shares)
Share-based compensation (in shares)	20,780
Share-based compensation	$ 50	199,820				$ 199,870
Net income				6,402,259		6,402,259
Purchase of Treasury stock (in shares)	(520,482)
Purchase of Treasury stock			(3,675,654)			(3,675,654)
Translation adjustment					(205,450)	(205,450)
Balance (in shares) at Dec. 31, 2016	9,193,162
Balance at Dec. 31, 2016	$ 26,966	6,368,455	(10,278,584)	59,469,493	(1,893,129)	$ 53,693,201
Shares issued - stock options exercised (in shares)	44,400					44,400
Shares issued - stock options exercised	$ 107	223,297				$ 223,404
Share-based compensation (in shares)	33,300
Share-based compensation	$ 80	239,519				239,599
Net income				4,451,751		$ 4,451,751
Purchase of Treasury stock (in shares)						0
Translation adjustment					931,026	$ 931,026
Balance (in shares) at Dec. 31, 2017	9,270,862
Balance at Dec. 31, 2017	$ 27,153	$ 6,831,271	$ (10,278,584)	$ 63,921,244	$ (962,103)	$ 59,538,981