NOTE 4:- MARKETABLE SECURITIES

Marketable securities with contractual maturities of less than one year are as follows:


	December 31,
	2010									2011
	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value		Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value
Government and corporate debentures - fixed interest rate	$	313,939	$	2,372	$	(85	)	$	316,226	$	504,749	$	3,534	$	(237	)	$	508,046
Government-sponsored enterprises		142,496		504		(100	)		142,900		40,088		238		—			40,326
Government and corporate debentures - floating interest rate		78,505		97		(10	)		78,592		95,086		129		(48	)		95,167

	$	534,940	$	2,973	$	(195	)	$	537,718	$	639,923	$	3,901	$	(285	)	$	643,539

Marketable securities with contractual maturities of over one year through five years are as follows:


	December 31,
	2010									2011
	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value		Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value
Government and corporate debentures - fixed interest rate	$	990,454	$	18,421	$	(1,731	)	$	1,007,144	$	1,103,254	$	14,854	$	(2,058	)	$	1,116,050
Government-sponsored enterprises		189,085		1,366		(552	)		189,899		295,235		2,061		(151	)		297,145
Government and corporate debentures - floating interest rate		120,206		297		(85	)		120,418		102,161		160		(1,729	)		100,592
Auction rate securities (*)		7,990		—		—			7,990		6,078		—		—			6,078

	$	1,307,735	$	20,084	$	(2,368	)	$	1,325,451	$	1,506,728	$	17,075	$	(3,938	)	$	1,519,865

Investments with continuous unrealized losses for less than 12 months and 12 months or greater and their related fair values were as follows:


	December 31, 2010
	Investments with continuous unrealized losses for less than 12 months					Investments with continuous unrealized losses for 12 months or greater					Total Investments with continuous unrealized losses
	Fair value		Unrealized losses			Fair value		Unrealized losses			Fair value		Unrealized losses
Government and corporate debentures - fixed interest rate	$	195,784	$	(1,816	)	$	—	$	—		$	195,784	$	(1,816	)
Government-sponsored enterprises		122,574		(649	)		4,999		(3	)		127,572		(652	)
Government and corporate debentures - floating interest rate		58,632		(47	)		15,834		(48	)		74,467		(95	)

	$	376,990	$	(2,512	)	$	20,833	$	(51	)	$	397,823	$	(2,563	)


	December 31, 2011
	Investments with continuous unrealized losses for less than 12 months					Investments with continuous unrealized losses for 12 months or greater					Total Investments with continuous unrealized losses
	Fair value		Unrealized losses			Fair value		Unrealized losses			Fair value		Unrealized losses
Government and corporate debentures - fixed interest rate	$	267,326	$	(2,225	)	$	27,490	$	(69	)	$	294,816	$	(2,294	)
Government-sponsored enterprises		131,540		(151	)		—		—			131,540		(151	)
Government and corporate debentures - floating interest rate		66,426		(1,634	)		14,741		(144	)		81,167		(1,778	)

	$	465,292	$	(4,010	)	$	42,231	$	(213	)	$	507,523	$	(4,223	)

(*)

The balance in 2010 was comprised of four auction rate securities, which have suffered from failed auctions since September 2007. During 2011 two of these securities were sold. As a result of the auction failures these auction rate securities do not have a readily determinable market value. As such, since 2008, the Company determines the fair values of these securities with the assistance of third- party valuating specialists (see Note 5).

As of December 31, 2010 and 2011, interest receivable amounted to $ 15,324 and $ 16,352, respectively, and is included within other current assets in the balance sheets.

During 2011 the Company did not recognize any other-than-temporary loss and recognized a gain of $ 2,017 on sale of auction rate securities that were impaired in 2010. The other-than-temporary loss recognized in earnings during 2010 was $ 785 relating to auction rate securities.

The Company recognized in 2009 other-than-temporary impairment in a total amount of $ 3,134 related to its auction rate securities loss and a gain of $ 1,857 on sale of marketable securities that were impaired in 2008.

The Company may recognize additional losses in the future should the market prospects of the issuers of these securities continue to deteriorate.