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 September 30, 2011, the Company has recorded the estimated fair value of available-for-sale securities in short-term and long-term investments of approximately $590.0 million and $45.7 million, respectively.

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

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

Corporate notes and bonds	$	345,409	$	211	$	(949)	$	-	$	344,671
Federal agency notes and bonds		239,360		532		(56)		-		239,836
Auction rate floating securities		24,300		-		(6,232)		-		18,068
Asset-backed securities		33,114		13		(5)		-		33,122
Total securities	$	642,183	$	756	$	(7,242)	$	-	$	635,697

During the three and nine months ended September 30, 2011, gross realized gains on sales of available-for-sale securities totaled $0.1 million. During the three and nine months ended September 30, 2011, there were no significant gross realized 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 nine months ended September 30, 2011, on available-for-sale securities included in stockholders' equity totaled $0.4 million. The amortized cost and estimated fair value of the available-for-sale securities at September 30, 2011, by maturity, are shown below (in thousands):

	September 30, 2011
			Estimated
	Cost		Fair Value

Available-for-sale
Due in one year or less	$	296,177	$	296,406
Due after one year through five years		321,706		321,223
Due after 10 years		24,300		18,068
	$	642,183	$	635,697

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 September 30, 2011, approximately $ 45.7 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 September 30, 2011, the Company's investments included auction rate floating securities with a fair value of $18.1 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 nine months 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 September 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	$	208,222	$	948	$	-	$	-
Federal agency notes and bonds		71,824		56		-		-
Auction rate floating securities		-		-		18,068		6,232
Asset-backed securities		9,322		5		-		-
Total securities	$	289,368	$	1,009	$	18,068	$	6,232

As of September 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.