Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts receivable, allowance	$ 115	$ 37
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0
Preferred stock, shares outstanding	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	12,256,980	12,257,000
Common stock, shares outstanding	10,844,113	10,844,000
Purchase of treasury shares	1,413,000	1,413,000
Series C Preferred Stock [Member]
Preferred stock, shares issued	0	550
Preferred stock, shares outstanding	0	550
Preferred stock, liquidation preference, value	$ 0	$ 550
Series B Convertible Preferred Stock [Member]
Preferred stock, shares issued	0	130
Preferred stock, shares outstanding	0	130
Preferred stock, liquidation preference, value	$ 0	$ 13