Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2014

Fair Value Measurements [Abstract]

Fair value measurements by level for assets and liabilities measured at fair value on a recurring basis

The following table summarizes fair value measurements by level at March 31, 2014 for assets and liabilities measured at fair value on a recurring basis:

(In thousands)	Level I		Level II		Level III			Total
Cash equivalents	$	57,238	$	—	$	—		$	57,238
Short-term investments		50,585		—		—			50,585
Warrant liabilities		—		—		(9,479	)		(9,479	)

The following table summarizes fair value measurements by level at December 31, 2013 for assets and liabilities measured at fair value on a recurring basis:

(In thousands)	Level I		Level II		Level III			Total
Cash equivalents	$	10,281	$	—	$	—		$	10,281
Short-term investments		27,085		—		—			27,085
Warrant liabilities		—		—		(24,182	)		(24,182	)