CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 303	$ 225
Preferred stock - par value (in dollars per share)	$ 1.00	$ 1.00
Preferred stock - shares authorized (in shares)	960,000	960,000
Preferred stock - outstanding (in shares)	0	0
Common stock - par value (in dollars per share)	$ 0.1	$ 0.1
Common stock - shares authorized (in shares)	7,500,000	7,500,000
Common stock - shares issued (in shares)	4,217,596	4,217,596
Common stock - shares outstanding (in shares)	4,217,596	4,217,596