Financial Instruments

The following is a summary of cash equivalents and available-for-sale securities as of the end of the periods presented:



	January 2, 2016									March 28, 2015
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Money market funds	$	222,433	$	—	$	—		$	222,433	$	235,583	$	—	$	—		$	235,583
Financial institution
securities	328,945		—		—			328,945		304,999		—		—			304,999
Non-financial institution
securities	673,436		38		(807		)	672,667		429,005		25		(6		)	429,024
Auction rate securities	10,500		—		(389		)	10,111		10,500		—		(188		)	10,312
Municipal bonds	65,920		577		(302		)	66,195		49,064		744		(152		)	49,656
U.S. government and
agency securities	298,492		21		(196		)	298,317		757,954		91		(129		)	757,916
Foreign government and
agency securities	136,384		—		(9		)	136,375		197,932		—		—			197,932
Mortgage-backed securities	1,138,412		6,504		(10,768		)	1,134,148		1,035,598		8,809		(4,171		)	1,040,236
Asset-backed securities	213,908		635		(876		)	213,667		211,487		1,130		(159		)	212,458
Debt mutual funds	101,350		—		(13,233		)	88,117		101,350		—		(6,150		)	95,200
Bank loans	102,724		31		(103		)	102,652		98,131		29		(60		)	98,100
Commercial mortgage-
backed securities	193,033		26		(2,658		)	190,401		40,132		133		(325		)	39,940
	$	3,485,537	$	7,832	$	(29,341	)	$	3,464,028	$	3,471,735	$	10,961	$	(11,340	)	$	3,471,356

The following tables show the fair values and gross unrealized losses of the Company’s investments, aggregated by investment category, for individual securities that have been in a continuous unrealized loss position for the length of time specified, as of January 2, 2016 and March 28, 2015:



	January 2, 2016
	Less Than 12 Months					12 Months or Greater					Total
(In thousands)	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
Non-financial institution securities	$	113,246	$	(807	)	$	—	$	—		$	113,246	$	(807	)
Auction rate securities	—		—			10,111		(389		)	10,111		(389		)
Municipal bonds	24,009		(148		)	3,408		(154		)	27,417		(302		)
U.S. government and
agency securities	167,906		(196		)	—		—			167,906		(196		)
Foreign government and
agency securities	9,986		(9		)	—		—			9,986		(9		)
Mortgage-backed securities	822,404		(9,365		)	55,649		(1,403		)	878,053		(10,768		)
Asset-backed securities	154,782		(749		)	25,470		(127		)	180,252		(876		)
Debt mutual funds	17,628		(2,372		)	70,489		(10,861		)	88,117		(13,233		)
Bank loans	41,534		(64		)	31,080		(39		)	72,614		(103		)
Commercial mortgage-
backed securities	182,372		(2,038		)	1,512		(620		)	183,884		(2,658		)
	$	1,533,867	$	(15,748	)	$	197,719	$	(13,593	)	$	1,731,586	$	(29,341	)



	March 28, 2015
	Less Than 12 Months					12 Months or Greater					Total
(In thousands)	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
Non-financial institution securities	$	7,190	$	(6	)	$	—	$	—		$	7,190	$	(6	)
Auction rate securities	—		—			10,312		(188		)	10,312		(188		)
Municipal bonds	10,014		(94		)	1,931		(58		)	11,945		(152		)
U.S. government and
agency securities	451,296		(129		)	—		—			451,296		(129		)
Mortgage-backed securities	442,786		(2,901		)	48,263		(1,270		)	491,049		(4,171		)
Asset-backed securities	75,009		(159		)	—		—			75,009		(159		)
Debt mutual funds	38,608		(1,392		)	56,592		(4,758		)	95,200		(6,150		)
Bank loans	65,085		(60		)	—		—			65,085		(60		)
Commercial mortgage-
backed securities	5,984		(268		)	944		(57		)	6,928		(325		)
	$	1,095,972	$	(5,009	)	$	118,042	$	(6,331	)	$	1,214,014	$	(11,340	)

As of January 2, 2016, the gross unrealized losses that had been outstanding for less than twelve months were primarily related to mortgage-backed securities, debt mutual funds and commercial mortgage-backed securities due to the general rising of the interest-rate environment and foreign currency movement. The gross unrealized losses that had been outstanding for more than twelve months were primarily related to debt mutual funds and mortgage-backed securities, which were primarily due to the same reasons stated above. The percentage of the losses to the total estimated fair value of the Company's investments was insignificant.

The Company reviewed the investment portfolio and determined that the gross unrealized losses on these investments as of January 2, 2016 and March 28, 2015 were temporary in nature as evidenced by the fluctuations in the gross unrealized losses within the investment categories. These investments are highly rated by the credit rating agencies and there have been no defaults on any of these securities, and we have received interest payments as they become due. Additionally, in the past several years a portion of the Company's investment in the mortgage-backed securities were redeemed or prepaid by the debtors at par. Furthermore, the aggregate of individual unrealized losses that had been outstanding for twelve months or more was not significant as of January 2, 2016 and March 28, 2015. The Company neither intends to sell these investments nor concludes that it is more-likely-than-not that it will have to sell them until recovery of their carrying values. The Company also believes that it will be able to collect both principal and interest amounts due to the Company at maturity, given the high credit quality of these investments and any related underlying collateral.

The amortized cost and estimated fair value of marketable debt securities (financial institution securities, non-financial institution securities, auction rate securities, municipal bonds, U.S. and foreign government and agency securities, mortgage-backed securities, asset-backed securities, bank loans and commercial mortgage-backed securities), by contractual maturity, are shown below. Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations without call or prepayment penalties.



	January 2, 2016
(In thousands)	Amortized Cost		Estimated Fair Value
Due in one year or less	$	1,232,756	$	1,232,713
Due after one year through five years	503,374		501,371
Due after five years through ten years	272,546		271,353
Due after ten years	1,153,078		1,148,041
	$	3,161,754	$	3,153,478

As of January 2, 2016, $1.78 billion of marketable debt securities with contractual maturities of greater than one year were classified as short-term investments. Additionally, the above table did not include investments in money market and mutual funds because these funds do not have specific contractual maturities.

Certain information related to available-for-sale securities is as follows:



	Three Months Ended						Nine Months Ended
(In thousands)	January 2, 2016			December 27, 2014			January 2, 2016			December 27, 2014
Proceeds from sale of available-for-sale securities	$	82,396		$	478,562		$	203,426		$	774,406
Gross realized gains on sale of available-for-sale securities	$	203		$	4,759		$	1,038		$	7,838
Gross realized losses on sale of available-for-sale securities	(221		)	(1,663		)	(439		)	(2,330		)
Net realized gains (losses) on sale of available-for-sale securities	$	(18	)	$	3,096		$	599		$	5,508
Amortization of premiums on available-for-sale securities	$	6,906		$	5,913		$	20,417		$	18,559

The cost of securities matured or sold is based on the specific identification method.