Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended										12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Embedded Derivative Financial Instruments	Dec. 31, 2012 Effect of a hypothetical 10% increase in the market price of common shares	Dec. 31, 2012 Warrants Issued October 2009	Dec. 31, 2011 Warrants Issued October 2009	Dec. 31, 2010 Warrants Issued October 2009	Dec. 31, 2009 Warrants Issued October 2009	Oct. 31, 2009 Warrants Issued October 2009 Y	Dec. 31, 2012 Maximum	Dec. 31, 2012 Maximum Embedded Derivative Financial Instruments	Dec. 31, 2012 Minimum Embedded Derivative Financial Instruments
Significant Accounting Policies [Line Items]
Short term highly liquid instruments, maturity date											90 days
Fair value of derivative liability	$ 54,854,000	$ 123,125,000				$ 54,854,000	$ 123,125,000	$ 230,069,000	$ 41,520,000	$ 48,300,000
Warrant derivative liability valuation assumptions, risk-free rate										2.37%
Warrant derivative liability valuation assumptions, remaining term										5
Warrant derivative liability valuation assumptions, volatility rate										119.00%
Warrant derivative liability fair value assumptions, risk-free rate	0.25%	0.36%
Derivative liability fair value assumptions, term	1 year 9 months 18 days	2 years 9 months 18 days										8 years	4 years 9 months 18 days
Warrant derivative liability fair value assumptions, volatility rate	95.00%	118.00%
Increase (Decrease) in the fair value of warrant derivative liability					6,400,000	35,600,000	22,600,000
Gain (loss) on change in fair value of derivative liability	(35,344,000)	(22,669,000)	(205,153,000)	20,000		(35,367,000)	(22,669,000)
Compensation (income) expense for change in fair value of warrants issued to former employees	18,075,000	9,294,000	5,207,000			200,000	(100,000)
Market price of common stock	$ 8.09				$ 8.90
Hypothetical increase in market price of common shares	10.00%
Change of control obligation				140,000,000
Maximum repayment of future revenue and receivables				150,000,000
Derivative liability fair value assumption, coupon rate												11.50%	3.00%
Derivative liability fair value assumptions, market yields												27.70%	10.70%
Long term debt redemption feature	$ 14,600,000			$ 14,600,000