Accrued Expenses - Components of Accrued Expenses (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Payables and Accruals [Abstract]
Development costs	$ 410	$ 834
Employee compensation	436	874
Professional fees	199	195
Interest	88	84
Other	13	0
Total Accrued Expenses	$ 1,146	$ 1,987