Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Allowance for doubtful accounts	$ 91	$ 91
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	2,500,000	2,500,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	12,731,678	12,731,678
Treasury stock, shares at cost	44,855	272,030
Series A Preferred Stock [Member]
Preferred stock, shares authorized	100,000	100,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Series B Preferred Stock [Member]
Preferred stock, shares authorized	100,000	100,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0