Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	9 Months Ended
	Sep. 30, 2012	Dec. 31, 2011
Significant Accounting Policies [Line Items]
Stock options exercise period	10 years
Shares of common stock reserved under EIP	10,000,000
Options outstanding	21,041,667	15,795,000
Number of shares exercisable	9,329,063
Common stock shares available	6,453,333	1,700,000
Risk-free interest period (in years)	4 years
Unrecognized estimated employee compensation cost related to non-vested stock options granted	$ 1,012,000
Non-vested stock options period granted expected to be recognized	4 years
Warrant
Significant Accounting Policies [Line Items]
Potentially dilutive shares of common stock excluded from calculation of weighted average number of shares	56,542,013
Convertible Debt
Significant Accounting Policies [Line Items]
Potentially dilutive shares of common stock excluded from calculation of weighted average number of shares	20,269,100
Convertible Preferred Stock
Significant Accounting Policies [Line Items]
Potentially dilutive shares of common stock excluded from calculation of weighted average number of shares	3,585,000
Equity Incentive Plan Twenty Eleven
Significant Accounting Policies [Line Items]
Shares of common stock reserved under EIP	15,000,000
Stock Plan 2001
Significant Accounting Policies [Line Items]
Options outstanding as a percentage of outstanding shares	18.00%
Number of shares exercisable	9,329,063
Minimum
Significant Accounting Policies [Line Items]
Estimated useful life of asset	2 years
Maximum
Significant Accounting Policies [Line Items]
Estimated useful life of asset	3 years