Quarterly report pursuant to Section 13 or 15(d)

Organization (Details Textual)

v3.8.0.1
Organization (Details Textual) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2017
Dec. 31, 2016
Organization [Line Items]        
Retained Earnings (Accumulated Deficit), Total $ (152,055)   $ (144,154)  
Cash and Cash Equivalents, at Carrying Value 20,572 $ 9,426 $ 27,813 $ 16,846
Net Cash Provided by (Used in) Operating Activities (6,745) $ (7,254)    
Restricted Cash and Cash Equivalents 5,526      
Unrestricted Cash $ 15,046