Fair Value of Financial Instruments and Investments (Tables)

6 Months Ended

Jun. 30, 2012

Financial Instruments Measured at Fair Value on Recurring Basis

The following table presents the Company’s cash and cash equivalents, investments, embedded derivatives and warrant liability including the hierarchy for its financial instruments measured at fair value on a recurring basis at June 30, 2012 and December 31, 2011:

June 30, 2012	Carrying Amount		Estimated Fair Value		Level 1		Level 2		Level 3
	(In thousands)
Assets:
Cash and cash equivalents:
Cash	$	21,553	$	21,553	$	21,553	$	—	$	—
Money market funds		70,910		70,910		70,910		—		—
Total cash and cash equivalents		92,463		92,463		92,463		—		—
Short-term investments:
Certificates of deposit		49,748		49,748		49,748		—		—
Total short-term investments		142,211		142,211		142,211		—		—
Restricted cash:
Certificates of deposit		2,930		2,930		2,930		—		—
Total restricted cash		2,930		2,930		2,930		—		—
	$	145,141	$	145,141	$	145,141	$	—	$	—
Liabilities:
Embedded derivatives:
Debt redemption features	$	948	$	948	$	—	$	—	$	948
Total embedded derivatives		948		948		—		—		948
Warrant liability		1,490		1,490		—		—		1,490
Total	$	2,438	$	2,438	$	—	$	—	$	2,438
December 31, 2011	Carrying Amount		Estimated Fair Value		Level 1		Level 2		Level 3
	(In thousands)
Assets:
Cash and cash equivalents:
Cash	$	8,680	$	8,680	$	8,680	$	—	$	—
Money market funds		105,414		105,414		105,414		—		—
Total cash and cash equivalents		114,094		114,094		114,094		—		—
Short-term investments:
Certificates of deposit		55,694		55,694		55,694		—		—
Total short-term investments		55,694		55,694		55,694		—		—
Restricted cash:
Certificates of deposit		2,580		2,580		2,580		—		—
Total restricted cash		2,580		2,580		2,580		—		—
Total	$	172,368	$	172,368	$	172,368	$	—	$	—

Changes in Fair Value of Financial Liabilities Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs

The following table provides a summary of the changes in fair value of the Company’s financial liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) during the six-month period ended June 30, 2012:

	Warrant Liability			Debt Redemption Features
Level 3
Balance at December 31, 2011	$	—		$	—
Valuation on May 9, 2012 (date of debt exchange transaction, see Note 7)		5,282			948
Unrealized gain		(3,792	)		—
Balance at June 30, 2012	$	1,490		$	948