Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Trade and other accounts receivable, allowance	$ 12	$ 0
Common stock, par value	$ 0.10	$ 0.10
Common stock, shares authorized	80,000,000	80,000,000
Common stock, shares issued	46,501,538	45,996,186
Common stock, shares outstanding	46,501,538	45,996,186