Stockholders' Equity - Summary of Warrants Outstanding to Purchase Common Stock (Detail) (USD $)			6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 $ 0.01 - 5.00 [Member]	Jun. 30, 2013 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	4,207,542	4,279,919		2,009,436
Weighted Average Remaining Contractual Life (Years)				1 year 4 months 24 days
Weighted Average Exercise Price	$ 3.78	$ 3.70		$ 3.88
Aggregate Intrinsic Value	$ 3,541,910			$ 1,128,531