Liquidity (Details Textual) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016		Sep. 30, 2016	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents	$ 38,231	$ 66,006	[1]	$ 74,632	$ 87,191

[1] Derived from the audited December 31, 2016 financial statements