Selected Balance Sheet Information (Details 2) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Accrued Expenses [Line Items]
Accrued manufacturing costs	$ 705	$ 83
Accrued clinical consulting services	690	674
Accrued vendor payments	229	150
Other accrued expenses	6	12
Total	$ 1,630	$ 919