Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Dec. 31, 2017	8,777,988
Balance at Dec. 31, 2017	$ 88	$ 14,877	$ (143)	$ 4,631	$ 19,453
Stock options exercised (in shares)
Stock options exercised
Net income				893	893
Stock compensation expense		13			13
Foreign currency translation adjustment			1		1
Unrealized gain on marketable securities			(17)		(17)
Balance (in shares) at Mar. 31, 2018	8,777,988
Balance at Mar. 31, 2018	$ 88	14,890	(159)	5,524	$ 20,343
Balance (in shares) at Dec. 31, 2018	8,817,988				8,817,988
Balance at Dec. 31, 2018	$ 88	15,050	(92)	10,875	$ 25,921
Stock options exercised (in shares)	33,000
Stock options exercised	$ 1	58			59
Net income				2,072	2,072
Stock compensation expense		25			25
Foreign currency translation adjustment			(1)		(1)
Unrealized gain on marketable securities
Balance (in shares) at Mar. 31, 2019	8,850,988				8,850,988
Balance at Mar. 31, 2019	$ 89	$ 15,133	$ (93)	$ 12,947	$ 28,076