Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2013

Fair Value Disclosures [Abstract]

Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques

The following table presents information about our financial assets and liabilities that are measured at fair value on a recurring basis, and indicates the fair value hierarchy of the valuation techniques we utilize to determine such fair value at March 31, 2013 and December 31, 2012.

	Fair Value as of March 31, 2013
(in thousands)	Level 1		Level 2		Level 3		Total
Assets:
Corporate debt securities	$	—	$	10,227	$	—	$	10,227

	Fair Value as of December 31, 2012
(in thousands)	Level 1		Level 2		Level 3		Total
Assets:
Corporate debt securities	$	—	$	7,679	$	—	$	7,679

Available-for-sale Securities

The following table sets forth the composition of securities available-for-sale as of March 31, 2013 and December 31, 2012.

	Maturity in Years	Amortized Cost		Unrealized					Fair Value
As of March 31, 2013 (in thousands)				Gains		Losses
Corporate debt securities	3 or less	$	10,250	$	9	$	(32	)	$	10,227
	Maturity in Years	Amortized Cost		Unrealized					Fair Value
As of December 31, 2012 (in thousands)				Gains		Losses
Corporate debt securities	3 or less	$	7,662	$	17	$	—		$	7,679