Marketable Securities:

The Company has evaluated its investment policies and determined that all of its investment securities are to be classified as available-for-sale. Available-for-sale securities are carried at fair value, with the unrealized gains and losses reported in Stockholders’ Equity under the caption “Accumulated other comprehensive loss.” Realized gains and losses on available-for-sale securities are included in “Other income (expense).” Net realized losses of $1, $0 and $1 were included in the Consolidated Statement of Operations for 2009, 2010 and 2011, respectively. The Company records other-than-temporary impairment charges for its available-for-sale investments when it intends to sell the securities, it is more-likely-than-not that it will be required to sell the securities before a recovery, or when it does not expect to recover the entire amortized cost basis of the securities. The cost of securities sold is based on the specific identification method.

As of December 31, 2011, the Company held one auction-rate security with a fair value of $363. The underlying asset of the Company’s auction-rate security consisted of a municipal bond with an auction reset feature. Due to auction failures in the marketplace, the Company will not have access to these funds unless (a) future auctions occur and are successful, (b) the security is called by the issuer, (c) the Company sells the security in an available secondary market, or (d) the underlying note matures. Currently, there are no active secondary markets. As of December 31, 2011, the Company has recorded a cumulative temporary unrealized impairment loss of $137 within “Accumulated other comprehensive loss” based upon its assessment of the fair value of this security. The Company believes that this impairment is temporary as it does not intend to sell this security, the Company will not be required to sell this security before recovery, and the Company expects to recover the amortized cost basis of these securities.

The Company has determined that the gross unrealized losses on its marketable securities at December 31, 2010 and 2011 are temporary in nature. The Company reviews its investment portfolio to identify and evaluate investments that have indications of possible impairment. Factors considered in determining whether a loss is other-than-temporary include the length of time and extent to which fair value has been less than the cost basis, credit quality and the Company’s ability and intent to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value.

At December 31, 2010 and 2011, marketable securities are categorized as follows:



	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses			Fair Value
December 31, 2010
U.S. Treasury notes	$	359	$	3	$	—		$	362
Auction rate securities	500		—		(233		)	267
Total marketable securities	$	859	$	3	$	(233	)	$	629
December 31, 2011
Municipal notes and bonds	$	70,475	$	60	$	(10	)	$	70,525
Auction rate securities	500		—		(137		)	363
Total marketable securities	$	70,975	$	60	$	(147	)	$	70,888

The amortized cost and estimated fair value of marketable securities classified by the maturity date listed on the security, regardless of the Consolidated Balance Sheet classification, is as follows at December 31, 2010 and 2011:



	December 31, 2010				December 31, 2011
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Due within one year	$	359	$	362	$	59,469	$	59,509
Due after one through five years	—		—		10,587		10,599
Due after five through ten years	—		—		314		312
Due after ten years	500		267		605		468
Total marketable securities	$	859	$	629	$	70,975	$	70,888

The following table summarizes the estimated fair value and gross unrealized holding losses of marketable securities, aggregated by investment instrument and period of time in an unrealized loss position at December 31, 2010 and 2011.



	In Unrealized Loss Position For Less Than 12 Months					In Unrealized Loss Position For Greater Than 12 Months
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
December 31, 2010
Tax-free auction rate securities	—		—			267		(233		)
Total marketable securities	$	—	$	—		$	267	$	(233	)
December 31, 2011
Municipal notes and bonds	7,291		(10		)	—		—
Tax-free auction rate securities	—		—			363		(137		)
Total marketable securities	$	7,291	$	(10	)	$	363	$	(137	)

See Note 4 for additional discussion regarding the fair value of the Company’s marketable securities.