Warrant Liabilities

9 Months Ended

Sep. 30, 2011

Warrant Liabilities [Abstract]

Warrant Liabilities

7. Warrant Liabilities

Liabilities measured at market value on a recurring basis include warrant liabilities resulting from the Company's past equity financings, including the underwritten public offering that closed on August 1, 2011. In accordance with ASC 815-40 (formerly EITF (Emerging Issues Task Force) 00-19, Accounting for Derivative Financial Instruments Indexed to and Potentially Settled in a Company's Own Stock, the warrant liabilities are being marked to market each quarter-end until they are completely settled. The warrants are valued using the Black-Scholes method. The warrants do not contain any down round provisions. The gain or loss resulting from the marked to market calculation is shown on the Consolidated Statements of Operations as Gain or Loss on warrant derivative liability. The Company recognized a gain of $4.3 million and $0.2 million for the three-month periods ended September 30, 2011 and 2010, respectively, and $5.5 million and $1.6 million for the nine-month periods ended September 30, 2011 and 2010, respectively.