The Company's policy for its short-term and long-term investments is to establish a high-quality portfolio that preserves principal, meets liquidity needs, avoids inappropriate concentrations and delivers an appropriate yield in relationship to the Company's investment guidelines and market conditions. Short-term and long-term investments consist of corporate and various government agency and municipal debt securities. The Company's investments in auction rate floating securities consist of investments in student loans. Management classifies the Company's short-term and long-term investments as available-for-sale. Available-for-sale securities are carried at fair value with unrealized gains and losses reported in stockholders' equity. Realized gains and losses and declines in value judged to be other than temporary, if any, are included in other expense in the condensed consolidated statement of operations. A decline in the market value of any available-for-sale security below cost that is deemed to be other than temporary, results in impairment of the fair value of the investment. The impairment is charged to earnings and a new cost basis for the security is established. Premiums and discounts are amortized or accreted over the life of the related available-for-sale security. Dividends and interest income are recognized when earned. The cost of securities sold is calculated using the specific identification method. At June 30, 2011, the Company has recorded the estimated fair value of available-for-sale securities in short-term and long-term investments of approximately $655.6 million and $22.4 million, respectively.

Available-for-sale securities consist of the following at June 30, 2011 (in thousands):

	June 30, 2011
							Other-Than-
			Gross		Gross		Temporary
			Unrealized		Unrealized		Impairment		Fair
	Cost		Gains		Losses		Losses		Value

Corporate notes and bonds	$	360,758	$	474	$	(128)	$	-	$	361,104
Federal agency notes and bonds		251,136		769		(8)		-		251,897
Auction rate floating securities		26,575		-		(6,691)		-		19,884
Asset-backed securities		45,011		38		-		-		45,049
Total securities	$	683,480	$	1,281	$	(6,827)	$	-	$	677,934

During the three and six months ended June 30, 2011, there were no significant gross realized gains and losses on sales of available-for-sale securities. Gross unrealized gains and losses are determined based on the specific identification method. The net adjustment to unrealized losses during the six months ended June 30, 2011, on available-for-sale securities included in stockholders' equity totaled $0.2 million. The amortized cost and estimated fair value of the available-for-sale securities at June 30, 2011, by maturity, are shown below (in thousands):

	June 30, 2011
			Estimated
	Cost		Fair Value

Available-for-sale
Due in one year or less	$	327,303	$	327,965
Due after one year through five years		329,602		330,085
Due after 10 years		26,575		19,884
	$	683,480	$	677,934

Expected maturities will differ from contractual maturities because the issuers of the securities may have the right to prepay obligations without prepayment penalties, and the Company views its available-for-sale securities as available for current operations. At June 30, 2011, approximately $ 22.4 million in estimated fair value expected to mature greater than one year has been classified as long-term investments since these investments are in an unrealized loss position, and management has both the ability and intent to hold these investments until recovery of fair value, which may be maturity.

As of June 30, 2011, the Company's investments included auction rate floating securities with a fair value of $19.9 million. The Company's auction rate floating securities are debt instruments with a long-term maturity and with an interest rate that is reset in short intervals through auctions. The negative conditions in the credit markets from 2008 through the first half of 2011 have prevented some investors from liquidating their holdings, including their holdings of auction rate floating securities. During the three months ended March 31, 2008, the Company was informed that there was insufficient demand at auction for the auction rate floating securities. As a result, these affected auction rate floating securities are now considered illiquid, and the Company could be required to hold them until they are redeemed by the holder at maturity. The Company may not be able to liquidate the securities until a future auction on these investments is successful.

During the three months ended March 31, 2010, the Company became aware of new circumstances that directly impacted the valuation of an asset-backed security that is owned by the Company. An unrealized loss on the asset-backed security, based on the Company's intent to hold the security until recovery of the fair value, had previously been recorded in stockholders' equity. Based on the new circumstances related to the investment, the Company determined that the impairment of the asset-backed security was other-than-temporary, as the Company believed it would not recover its investment even if the asset were held to maturity. A $0.3 million impairment charge was therefore recorded in other expense, net, during the three months ended March 31, 2010 related to the asset-backed security. The asset-backed security was sold in April 2010.

The following table shows the gross unrealized losses and the fair value of the Company's investments, with unrealized losses that are not deemed to be other-than-temporarily impaired aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at June 30, 2011 (in thousands):

	Less Than 12 Months				Greater Than 12 Months
			Gross				Gross
	Fair		Unrealized		Fair		Unrealized
	Value		Loss		Value		Loss

Corporate notes and bonds	$	79,304	$	128	$	-	$	-
Federal agency notes and bonds		18,892		8		-		-
Auction rate floating securities		-		-		19,884		6,691
Asset-backed securities		1,790		-		-		-
Total securities	$	99,986	$	136	$	19,884	$	6,691

As of June 30, 2011, the Company has concluded that the unrealized losses on its investment securities are temporary in nature and are caused by changes in credit spreads and liquidity issues in the marketplace. Available-for-sale securities are reviewed quarterly for possible other-than-temporary impairment. This review includes an analysis of the facts and circumstances of each individual investment such as the severity of loss, the length of time the fair value has been below cost, the expectation for that security's performance and the creditworthiness of the issuer. Additionally, the Company does not intend to sell and it is not more-likely-than-not that the Company will be required to sell any of the securities before the recovery of their amortized cost basis.