Stockholders' Equity - Summary of Warrants Outstanding to Purchase Common Stock (Detail) (USD $)			3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014 $ 0.01 - 5.00 [Member]	Mar. 31, 2014 Midcap warrant [Member] $ 0.01 - 5.00 [Member]
Warrants, by Exercise Price Range [Line Items]
Range of Exercise Prices, minimum			$ 0.01
Range of Exercise Prices, maximum			$ 5.00
Number Outstanding	3,476,376	4,192,927		1,663,114
Weighted Average Remaining Contractual Life (Years)				1 year 2 months 23 days
Weighted Average Exercise Price	$ 4.12	$ 3.82		$ 3.56
Aggregate Intrinsic Value	$ 15,034,087			$ 8,121,117