Selected Balance Sheet Information (Details 2) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accrued Expenses [Line Items]
Accrued manufacturing costs	$ 661	$ 14
Accrued clinical consulting services	658	2,211
Accrued vendor payments	193	400
Other accrued expenses	14	2
Total	$ 1,526	$ 2,627