Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Accrued Liabilities
Employee bonuses	$ 549	$ 215
Accrued interest payable	531	451
Accrued restructuring costs	364
Accrued professional fees and other	307	186
Total accrued liabilities	$ 1,751	$ 852