Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accrued Liabilities
Employee bonuses	$ 621	$ 215
Accrued retention bonus	638
Accrued interest payable		451
Accrued professional fees and other	84	186
Total accrued liabilities	$ 1,343	$ 852