Derivative Instruments - Additional Information (Detail) (USD $)
3 Months Ended 6 Months Ended
Jun. 30, 2013
Jun. 30, 2013
Jan. 12, 2011
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]      
Fair value assumption stock price $ 0.20 $ 0.20  
Fair value assumption conversion price $ 1.25 $ 1.25  
Expected volatility rate   160.00%  
Remaining term of expected volatility   4 years 3 months 18 days  
Risk-free interest rate   1.12%  
Fair value of embedded conversion feature Increased/Decreased $ 10,800,000 $ 10,600,000  
Issuance of common stock 10,000,000 10,000,000  
Amended and Restated Reimbursement Notes [Member]
     
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]      
Fair value assumption stock price $ 0.20 $ 0.20  
Fair value assumption conversion price $ 0.50 $ 0.50  
Expected volatility rate   184.00%  
Remaining term of expected volatility   10 months  
Risk-free interest rate   0.15%  
Fair value of embedded conversion feature Increased/Decreased   39,000  
Amended and Restated Bridge Notes [Member]
     
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]      
Fair value assumption stock price $ 0.20 $ 0.20  
Fair value assumption conversion price $ 0.50 $ 0.50  
Expected volatility rate   160.00%  
Remaining term of expected volatility   4 years 3 months 18 days  
Risk-free interest rate   1.12%  
Fair value of embedded conversion feature Increased/Decreased   57,000  
Amended and Restated August 2009 Warrants [Member]
     
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]      
Fair value assumption stock price $ 0.20 $ 0.20  
Expected volatility rate   144.41%  
Remaining term of expected volatility   6 years 1 month 6 days  
Risk-free interest rate   1.41%  
Number of warrants sold to MHR   3,700,000  
Warrants exercised with exercise price   $ 0.50  
Fair value assumption exercise price $ 0.50 $ 0.50  
Fair value of warrants increased 330,000 290,000  
Warrants expiry date   Jul. 08, 2019  
Amended and Restated August 2010 Warrants [Member]
     
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]      
Fair value assumption stock price $ 0.20 $ 0.20  
Expected volatility rate   144.41%  
Remaining term of expected volatility   6 years 1 month 6 days  
Risk-free interest rate   1.41%  
Number of warrants sold to MHR   2,600,000  
Assumption exercise price   $ 0.50  
Fair value of warrants decreased   200,000  
Amended and Restated June 2010 Warrants [Member]
     
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]      
Fair value assumption stock price $ 0.20 $ 0.20  
Expected volatility rate   145.00%  
Remaining term of expected volatility   6 years 1 month 6 days  
Risk-free interest rate   1.67%  
Issuance of common stock 10,000,000 10,000,000  
Warrants exercised with exercise price   $ 0.50  
Fair value of warrants increased   20,000  
Warrants expiry date   Jul. 08, 2019  
Number of warrants issued 865,000 865,000  
Warrants extended expiry date   Jul. 08, 2019  
Reduced exercise price of warrants   $ 0.50  
August 2010 Investor Warrants [Member]
     
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]      
Fair value assumption stock price $ 0.20 $ 0.20  
Expected volatility rate   187.43%  
Remaining term of expected volatility   2 years 2 months  
Risk-free interest rate   0.36%  
Number of warrants sold to MHR   2,600,000  
Warrants expiry date   Aug. 26, 2015  
Assumption exercise price   $ 1.26  
Fair value of warrants decreased 100,000 100,000  
Exercise price of the warrants issued   $ 1.26  
Number of warrants exercised by unrelated investors     200,000
Amended and Restated August 2010 MHR Waiver Warrants [Member]
     
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]      
Fair value assumption stock price $ 0.20 $ 0.20  
Expected volatility rate   144.41%  
Remaining term of expected volatility   6 years 1 month 6 days  
Risk-free interest rate   1.41%  
Number of warrants sold to MHR   975,000  
Fair value of warrants increased 100,000 100,000  
Warrants extended expiry date   Jul. 08, 2019  
Reduced exercise price of warrants   $ 0.50  
Assumption exercise price   $ 0.50  
Amended and Restated July 2011 Warrants [Member]
     
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]      
Fair value assumption stock price $ 0.20 $ 0.20  
Expected volatility rate   144.41%  
Remaining term of expected volatility   6 years 1 month 6 days  
Risk-free interest rate   1.41%  
Number of warrants sold to MHR   3,010,000  
Fair value of warrants increased 200,000 200,000  
Warrants extended expiry date   Jul. 08, 2019  
Reduced exercise price of warrants   $ 0.50  
Assumption exercise price   $ 0.50  
July 2011 Investor Warrants [Member]
     
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]      
Fair value assumption stock price $ 0.20 $ 0.20  
Expected volatility rate   178.06%  
Remaining term of expected volatility   3 years 1 month 6 days  
Risk-free interest rate   0.36%  
Warrants expiry date   Jul. 06, 2016  
Number of warrants issued 3,010,000 3,010,000  
Assumption exercise price   $ 1.09  
Fair value of warrants decreased 100,000 100,000  
Exercise price of the warrants issued   $ 1.09  
Amended and Restated July 2011 MHR Waiver Warrants [Member]
     
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]      
Fair value assumption stock price $ 0.20 $ 0.20  
Expected volatility rate   144.41%  
Remaining term of expected volatility   6 years 1 month 6 days  
Risk-free interest rate   1.41%  
Number of warrants sold to MHR   795,000  
Fair value of warrants increased 100,000 100,000  
Warrants extended expiry date   Jul. 08, 2019  
Reduced exercise price of warrants   $ 0.50  
Assumption exercise price   $ 0.50  
2013 Restructuring Warrants [Member]
     
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]      
Fair value assumption stock price $ 0.20 $ 0.20  
Expected volatility rate   144.41%  
Remaining term of expected volatility   6 years 1 month 6 days  
Risk-free interest rate   1.41%  
Fair value of embedded conversion feature Increased/Decreased   $ 300,000  
Reduced exercise price of warrants   $ 0.50  
Assumption exercise price   $ 0.50  
Inception date   May 07, 2014