Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowance for doubtful accounts on trade accounts receivable	$ 53	$ 107
Property and equipment, accumulated depreciation and amortization	6,143	5,889
Intangible assets, accumulated amortization	$ 7,712	$ 7,433
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	30,000,000	30,000,000
Common stock, shares issued	16,913,430	16,711,752
Common stock, shares outstanding	16,727,599	16,525,681
Treasury stock, shares	185,831	185,831