Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Accrued Liabilities, Current [Abstract]
Compensation and benefits	$ 1,174	$ 1,036
Legal and professional fees	289	145
Consulting and other vendors	271	208
Interest and final payment fee	269	131
Deferred rent	101	46
Taxes	54	189
Other	101	14
Total accrued expenses	$ 2,259	$ 1,769