Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2012

Summary of Significant Accounting Policies [Abstract]

Summary of Financial Assets and Liabilities Measured at Fair Market Value on Recurring Basis

Financial assets and liabilities measured at fair market value on a recurring basis as of September 30, 2012 and December 31, 2011 are summarized below (in thousands):

	Fair Value at September 30, 2012						Fair Value at December 31, 2011
	Level 1		Level 2		Level 3		Level 1		Level 2		Level 3
Assets
Corporate debt and auction rate securities	$	-	$	17,672	$	-	$	-	$	4,205	$	-
Liabilities
Warrant liability	$	-	$	-	$	769	$	-	$	-	$	368

Summarized Activity of Level 3 Inputs Measured on Recurring Basis

The following table summarizes the activity of Level 3 inputs measured on a recurring basis as of September 30, 2012 (in thousands):

	Fair Value Measurements of Warrants Using Significant Unobservable Inputs (Level 3)
Balance at December 31, 2011	$	368
Change in fair value of Warrant liability		401
Balance at September 30, 2012	$	769

Short-term Investments Classified as Available-For-Sale

Short-term investments classified as available-for-sale as of September 30, 2012 and December 31, 2011 were comprised of (in thousands):

	September 30, 2012								December 31, 2011
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Auction rate securities	$	3,373	$	1,032	$	-	$	4,405	$	3,373	$	832	$	-	$	4,205
Corporate debt securities		13,263		4		-		13,267		-		-		-		-
Total	$	16,636	$	1,036	$	-	$	17,672	$	3,373	$	832	$	-	$	4,205