Financial Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability current	$ 2,053,000	$ 17,190,000
Derivative liability non-current	52,720	296,194
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability current	2,053,000	17,190,000
Derivative Liability - Total	2,105,720	17,486,194
Fair Value, Measurements, Recurring | Conversion Options | 8% convertible promissory notes
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability current	1,984,000	12,400,000
Fair Value, Measurements, Recurring | Conversion Options | 12% Convertible promissory notes
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability current	69,000
Fair Value, Measurements, Recurring | Warrant | 8% convertible promissory notes
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability current		4,790,000
Fair Value, Measurements, Recurring | Placement Agent | Warrant
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability non-current	52,720	296,194
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability current	0	0
Derivative Liability - Total	0	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Conversion Options | 8% convertible promissory notes
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability current	0	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Conversion Options | 12% Convertible promissory notes
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability current	0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Warrant | 8% convertible promissory notes
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability current		0
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | Placement Agent | Warrant
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability non-current	0	0
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability current	0	0
Derivative Liability - Total	0	0
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Conversion Options | 8% convertible promissory notes
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability current	0	0
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Conversion Options | 12% Convertible promissory notes
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability current	0
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Warrant | 8% convertible promissory notes
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability current		0
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Placement Agent | Warrant
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability non-current	0	0
Fair Value, Inputs, Level 3 | Conversion Options | 8% convertible promissory notes
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Liability - Total	1,984,000	12,400,000	610,000
Fair Value, Inputs, Level 3 | Warrant | 8% convertible promissory notes
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Liability - Total	0	4,790,000	220,000
Fair Value, Inputs, Level 3 | Placement Agent | Warrant
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability non-current	52,720	296,194	81,716
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability current	2,053,000	17,190,000
Derivative Liability - Total	2,105,720	17,486,194
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Conversion Options | 8% convertible promissory notes
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability current	1,984,000	12,400,000
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Conversion Options | 12% Convertible promissory notes
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability current	69,000
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Warrant | 8% convertible promissory notes
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability current		4,790,000
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Placement Agent | Warrant
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability non-current	$ 52,720	$ 296,194