Debt - Schedule of Aggregate Advances under the Loan and Security Agreement (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Debt Disclosure [Abstract]
Aggregate advances under loan and security agreement	$ 3,000,000	$ 1,000,000
Less unamortized discount	(51,762)	(20,208)
Total debt, net of debt discount	2,948,238	979,792
Current portion of long-term debt, net of current portion of unamortized discount	(1,069,802)
Long-term debt, net of current portion	$ 1,878,436	$ 979,792