Derivative Liability and Fair Value Measurements (Schedule of Fair Value Level 3 warrant liabilities) (Detail) (Warrant Liabilities [Member], USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Warrant Liabilities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value - beginning of period	$ 12,035,816	$ 0
Warrants issue during period	0	9,067,282
Reclassification (reset expiration) of warrant liabilities to Additional Paid-in Capital	(117,010)	(526,245)
Reclassification Of Warrant Exercises To Additional Paid-In Capital	(979,793)	(80,500)
Change in fair value for the period	(2,575,262)	3,575,278
Fair value - end of period	$ 8,363,751	$ 12,035,816