Operating Assets and Liabilities - Accrued liabilities (Details) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Operating Assets and Liabilities    
Accrued amounts due in accordance with the Amendment (Note 3.4) $ 11,757  
Professional advisors 910 $ 4,042
Contract research and manufacturing organizations 77 715
Other 299 310
Total $ 13,043 $ 5,067