Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Accumulated depreciation	$ 5,758	$ 5,471
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, par value	$ .0005	$ .0005
Preferred stock, shares issued
Common stock, shares authorized	50,000,000	50,000,000
Common stock, par value	$ .0005	$ .0005
Common stock, shares issued	28,108,746	27,696,593
Treasury stock, shares	16,566,701	16,566,701