Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2012

Summary of Significant Accounting Policies [Abstract]

Fair value measurements for assets and liabilities on recurring basis

The following table summarizes fair value measurements by level at December 31, 2012 for assets and liabilities measured

at fair value on a recurring basis:

(In thousands)	Level I		Level II		Level III		Total
Cash equivalents	$	13,188	$	—	$	—	$	13,188
Short-term investments		24,000		—		—		24,000
Warrant liabilities		—		—		3,972		3,972

The following table summarizes fair value measurements by level at December 31, 2011 for assets and liabilities measured

at fair value on a recurring basis:

(In thousands)	Level I		Level II		Level III		Total
Cash equivalents	$	17,073	$	—	$	—	$	17,073
Short-term investments		18,058		—		—		18,058
Warrant liabilities		—		—		6,739		6,739