Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]
Balance at Dec. 31, 2015	$ 36,907	$ 133,331	$ (869)	$ (95,555)
Balance, Shares at Dec. 31, 2015		12,092,598
Net loss	500
Balance at Mar. 31, 2016	37,873
Balance at Dec. 31, 2015	36,907	$ 133,331	(869)	(95,555)
Balance, Shares at Dec. 31, 2015		12,092,598
Exercise of stock options	$ 1,082	$ 1,082
Exercise of stock options, Shares	371,845	371,845
Share-based compensation, including issuance of restricted stock	$ 1,247	$ 1,247
Share-based compensation, including issuance of restricted stock, Shares		67,905
Net loss	(1,052)			(1,052)
Foreign currency translation adjustment, net of tax	(79)		(79)
Unrealized gain on investments, net of tax	7		7
Balance at Dec. 31, 2016	$ 38,112	$ 135,660	(941)	(96,607)
Balance, Shares at Dec. 31, 2016	12,532,348	12,532,348
Balance at Mar. 31, 2016	$ 37,873
Net loss	(185)
Balance at Jun. 30, 2016	38,166
Net loss	(106)
Balance at Sep. 30, 2016	38,790
Net loss	(1,261)
Balance at Dec. 31, 2016	$ 38,112	$ 135,660	(941)	(96,607)
Balance, Shares at Dec. 31, 2016	12,532,348	12,532,348
Net loss	$ 202
Balance at Mar. 31, 2017	39,206
Balance at Dec. 31, 2016	$ 38,112	$ 135,660	(941)	(96,607)
Balance, Shares at Dec. 31, 2016	12,532,348	12,532,348
Cumulative effect of accounting changes	$ 404		15	389
Exercise of stock options	$ 174	$ 174
Exercise of stock options, Shares	54,692	54,692
Share-based compensation, including issuance of restricted stock	$ 1,757	$ 1,757
Share-based compensation, including issuance of restricted stock, Shares		77,449
Net loss	(9,058)			(9,058)
Foreign currency translation adjustment, net of tax	41	$ 31	10
Balance at Dec. 31, 2017	$ 31,430	$ 137,622	(916)	(105,276)
Balance, Shares at Dec. 31, 2017	12,664,489	12,664,489
Balance at Mar. 31, 2017	$ 39,206
Net loss	(2,560)
Balance at Jun. 30, 2017	37,099
Net loss	(2,468)
Balance at Sep. 30, 2017	35,238
Net loss	(4,232)
Balance at Dec. 31, 2017	$ 31,430	$ 137,622	$ (916)	$ (105,276)
Balance, Shares at Dec. 31, 2017	12,664,489	12,664,489