Future Minimum Payments Under Loans Payable (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Debt Disclosure [Abstract]
2015 (3 months remaining)	$ 3,458
2016	3,499
2017	4,644
2018	4,269
Long-term Debt, Gross, Total	15,870
Less amount representing interest	(2,236)
Less discount	(617)
Less deferred charges	(540)
Less current portion Loans Payable Current	(4,217)	$ (11,722)
Loans payable, net of current portion and discount	$ 8,260	$ 8,930