Accrued Expenses - Components of Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Payables and Accruals [Abstract]
Development costs	$ 179	$ 834
Employee compensation	125	874
Professional fees	224	195
Interest	88	84
Other	2	0
Total Accrued Expenses	$ 618	$ 1,987