Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Trade and other accounts receivable, allowance	$ 26	$ 36
Common stock, par value	$ 0.10	$ 0.10
Common stock, shares authorized	80,000,000	80,000,000
Common stock, shares issued	38,161,009	37,199,519
Common stock, shares outstanding	38,161,009	37,199,519