Accounts Payable and Accrued Expenses - Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Payables And Accruals [Abstract]
Trade payables	$ 1,088	$ 553
Employee compensation, benefits, and related accruals	762	1,077
Consulting and contracted research	506	774
Professional fees	214	180
Other	55	80
Total	$ 2,625	$ 2,664