Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in-Capital [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Total
Balance at Dec. 31, 2017	$ 17	$ 134,646	$ (38,536)	$ 251	$ 31,248	$ 127,626
Balance, shares at Dec. 31, 2017	11,780,000
Stock option exercises, including related income tax benefit		221				221
Stock option exercises, including related income tax benefit, shares	50,000
Stock-based compensation expense		672				672
Net income					2,811	2,811
Translation adjustments				(256)		(256)
Balance at Mar. 31, 2018	$ 17	135,539	(38,536)	(5)	34,059	131,074
Balance, shares at Mar. 31, 2018	11,830,000
Balance at Dec. 31, 2018	$ 18	138,703	(38,536)	(1,313)	54,021	$ 152,893
Balance, shares at Dec. 31, 2018	12,183,000					12,183,048
Stock option exercises, including related income tax benefit		592				$ 592
Stock option exercises, including related income tax benefit, shares	72,000
Stock-based compensation expense		800				800
Net income					4,675	4,675
Translation adjustments				438		438
Balance at Mar. 31, 2019	$ 18	$ 140,095	$ (38,536)	$ (875)	$ 58,696	$ 159,398
Balance, shares at Mar. 31, 2019	12,255,000					12,255,374