Going Concern (Details Textual) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Retained Earnings (Accumulated Deficit)	$ (194,170)	$ (172,034)
Cash and Cash Equivalents, at Carrying Value, Total	$ 17,116	$ 19,055	$ 20,818	$ 17,525