Reconciliation of Derivative Liability Used in Determining Fair Value (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Derivative [Line Items]
Beginning Balance	$ 17,190,000
Fair value of derivative liability	(6,851,504)	5,475,424
Ending Balance	11,755,000
Conversion options | 8% convertible promissory notes
Derivative [Line Items]
Beginning Balance	12,400,000	610,000
Fair value of derivative liability	1,025,139	545,425
Change in fair value	(5,021,139)	3,634,575
Ending Balance	8,404,000	4,790,000
Warrant | 8% convertible promissory notes
Derivative [Line Items]
Beginning Balance	4,790,000	220,000
Fair value of derivative liability	391,365	249,151
Change in fair value	(1,830,365)	1,840,849
Ending Balance	3,351,000	2,310,000
Placement agent | Warrant
Derivative [Line Items]
Beginning Balance	296,194	81,716
Fair value of derivative liability	0	0
Change in fair value	(120,973)	134,300
Ending Balance	175,221	216,016
Derivative liabilities - current
Derivative [Line Items]
Beginning Balance	17,190,000	830,000
Fair value of derivative liability	1,416,504	794,576
Change in fair value	(6,851,504)	5,475,424
Ending Balance	11,755,000	7,100,000
Derivative liabilities - total
Derivative [Line Items]
Beginning Balance	17,486,194	911,716
Fair value of derivative liability	1,416,504	794,576
Change in fair value	(6,972,477)	5,609,724
Ending Balance	$ 11,930,221	$ 7,316,016