Accrued Expenses - Components of Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Payables and Accruals [Abstract]
Development costs	$ 160	$ 931
Employee compensation	915	573
Professional fees	77	194
Interest	0	88
Other	1	8
Total accrued expenses	$ 1,153	$ 1,794