Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Accrued Liabilities And Other Liabilities [Abstract]
Accrued compensation	$ 777	$ 571
Accrued contracted research and development costs	1,510	863
Accrued professional and consulting fees	639	863
Accrued other and other current liabilities	87	50
Total accrued and other current liabilities	$ 3,013	$ 2,347