Accrued Liabilities (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 18, 2018 employee	Dec. 31, 2017 USD ($)
Accrued compensation and other payroll liabilities	$ 368		$ 306
Workforce reduction severance	360
Workforce reduction related expenses	1,300
Legal costs	109		91
Accrued interest	42		38
Other research and development expenses	674		522
Other general and administrative expenses	32		53
Total	1,585		$ 1,010
Number of employees | employee		5
Workforce (as a percentage)		33.00%
General and administrative
Workforce reduction related expenses	600
Research and development
Workforce reduction related expenses	$ 700