We classify our investment securities as available-for-sale and report them at fair value with the related unrealized gains and losses included in accumulated other comprehensive income, a component of shareholders’ equity, net of tax. We classify investment securities with original maturities greater than 90 days, but less than or equal to 365 days as current assets.

The following table presents the amortized cost, gross unrealized gains and losses and fair value for investments securities aggregated by major security type:



	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value
	(In thousands)
June 30, 2011
Corporate bonds	$	16,512	$	32	$	(4	)	$	16,540
Commercial paper	19,980		7		—			19,987
Certificate of deposit	3,499		1		—			3,500
Total	$	39,991	$	40	$	(4	)	$	40,027

We had no investment securities as of December 31, 2010. The following table summarizes the gross unrealized losses and fair value of fixed income securities by the length of time that individual securities have been in a continuous unrealized loss position:



	Less Than 12 Months					12 Months or More		Total Fair Value		Total Unrealized Loss
	Fair Value		Unrealized Loss			Fair Value	Unrealized Loss	Total Fair Value		Total Unrealized Loss
	(In thousands)
June 30, 2011
Fixed income securities
Corporate bonds	$	2,999	$	(4	)	—	—	$	2,999	$	(4	)
Total fixed income securities	$	2,999	$	(4	)	—	—	$	2,999	$	(4	)

We did not record any other-than-temporary impairment losses during the three and six-month periods ended June 30, 2011 because we do not intend to sell these investments and it is more likely than not that we will not be required to sell theses investments before recovery of their amortized cost bases, which may be maturity.

The scheduled maturities of our fixed income securities are as follows:



	Amortized Cost		Fair Value
	(In thousands)
June 30, 2011
Due in one year or less	$	25,983	$	25,988
Due after one year through five years	14,008		14,039
Due after five years through ten years	—		—
Due after ten years	—		—
Total	$	39,991	$	40,027

Fair value is the price that would be received from selling an asset in an orderly transaction between market participants at the measurement date. Fair value is estimated by applying the following hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement:

Level 1 – Quoted prices in active markets for identical assets or liabilities.

Level 2 – Observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Level 3 – Inputs that are generally unobservable and typically reflect management’s estimate of assumptions that market participants would use in pricing the asset or liability.

The following table is a summary of our assets measured at fair value on a recurring basis:



	Level 1		Level 2		Level 3		Fair value
	(In thousands)
June 30, 2011
Corporate bonds	$	—	$	16,540	$	—	$	16,540
Commercial paper	—		19,987		—		19,987
Certificate of deposit	—		3,500		—		3,500
Total	$	—	$	40,027	$	—	$	40,027

We had no assets measured at fair value on a recurring basis as of December 31, 2010. We based the fair value of our investment securities on quoted prices in active markets for similar assets. We had no transfers between Level 1, Level 2 or Level 3 assets during the three and six-month periods ended June 30, 2011.