Marketable Securities

12 Months Ended

Dec. 31, 2012

Marketable Securities

Marketable Securities

4. Marketable Securities

        Available-for-sale securities, all of which have maturities of twelve months or less, as of December 31, 2012 consisted of the following:

	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
	(in thousands)
December 31, 2012:
Certificate of deposit	$	240	$	—	$	—		$	240
Commercial paper		12,479				(14	)		12,465
Corporate debt securities		59,557		3		(27	)		59,533
Total	$	72,276	$	3	$	(41	)	$	72,238

        The aggregate fair value of securities held by the Company in an unrealized loss position for less than 12 months as of December 31, 2012 was $51.4 million, representing 18 securities. To determine whether an other-than-temporary impairment exists, the Company performs an analysis to assess whether it intends to sell, or whether it would more likely than not be required to sell, the security before the expected recovery of the amortized cost basis. Where the Company intends to sell a security, or may be required to do so, the security's decline in fair value is deemed to be other-than-temporary and the full amount of the unrealized loss is recognized on the statement of comprehensive loss as an other-than-temporary impairment charge. When this is not the case, the Company performs additional analysis on all securities to evaluate losses associated with the creditworthiness of the security. Credit losses are identified where the Company does not expect to receive cash flows, based on using a single best estimate, sufficient to recover the amortized cost basis of a security and amount of the loss recognized in other income (expense).

        Marketable securities in an unrealized loss position as of December 31, 2012 consisted of the following:

	Aggregate Fair Value		Unrealized Losses
	(in thousands)
December 31, 2012:
Commercial paper		12,465		(14	)
Corporate debt securities		38,899		(27	)
	$	51,364		(41	)

        The Company does not intend to sell and it is not more likely than not that the Company will be required to sell the above investments before recovery of the amortized cost basis, which may be maturity. The Company determined that there was no material change in the credit risk of the above investments. As a result, the Company determined it did not hold any investments with an other-than-temporary-impairment as of December 31, 2012.