Cash, Cash Equivalents, and Investments

Cash, cash equivalents, and investments consisted of the following (in thousands):



	October 1, 2017		December 31, 2016
Cash	$	104,649	$	77,307
Money market instruments	6,700		2,334
Cash and cash equivalents	111,349		79,641
Treasury bills	70,184		67,175
Corporate bonds	65,569		141,188
Euro liquidity fund	52,312		46,499
Asset-backed securities	47,840		69,614
Sovereign bonds	20,945		7,298
Municipal bonds	8,805		6,517
Agency bonds	7,606		2,903
Short-term investments	273,261		341,194
Corporate bonds	245,940		169,952
Treasury bills	63,602		92,280
Asset-backed securities	59,069		26,946
Sovereign bonds	8,026		23,585
Agency bonds	5,639		10,339
Municipal bonds	4,225		1,233
Long-term investments	386,501		324,335
	$	771,111	$	745,170

Treasury bills consist of debt securities issued by the U.S. government; corporate bonds consist of debt securities issued by both domestic and foreign companies; the Euro liquidity fund invests in a portfolio of investment-grade bonds; asset-backed securities consist of debt securities collateralized by pools of receivables or loans with credit enhancement; sovereign bonds consist of direct debt issued by foreign governments; municipal bonds consist of debt securities issued by state and local government entities; and agency bonds consist of domestic or foreign obligations of government agencies and government sponsored enterprises that have government backing. The Euro liquidity fund is denominated in Euros, and the remaining securities are denominated in U.S. Dollars.

The following table summarizes the Company’s available-for-sale investments as of October 1, 2017 (in thousands):



	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Short-term:
Treasury bills	$	70,311	$	—	$	(127	)	70,184
Corporate bonds	65,484		91		(6		)	65,569
Euro liquidity fund	51,929		383		—			52,312
Asset-backed securities	47,839		13		(12		)	47,840
Sovereign bonds	20,974		5		(34		)	20,945
Municipal bonds	8,805		—		—			8,805
Agency bonds	7,600		6		—			7,606
Long-term:
Corporate bonds	245,046		1,013		(119		)	245,940
Treasury bills	63,704		—		(102		)	63,602
Asset-backed securities	59,038		76		(45		)	59,069
Sovereign bonds	8,059		7		(40		)	8,026
Agency bonds	5,630		9		—			5,639
Municipal bonds	4,219		9		(3		)	4,225
	$	658,638	$	1,612	$	(488	)	$	659,762

The following table summarizes the Company’s gross unrealized losses and fair values for available-for-sale investments in an unrealized loss position as of October 1, 2017 (in thousands):



	Unrealized Loss Position For:
	Less than 12 Months					12 Months or Greater					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
Treasury bills	$	95,174	$	(150	)	$	33,627	$	(79	)	$	128,801	$	(229	)
Asset-backed securities	51,878		(55		)	8,770		(2		)	60,648		(57		)
Corporate bonds	20,106		(33		)	15,154		(92		)	35,260		(125		)
Sovereign bonds	2,495		(5		)	19,854		(69		)	22,349		(74		)
Municipal bonds	1,356		(3		)	—		—			1,356		(3		)
	$	171,009	$	(246	)	$	77,405	$	(242	)	$	248,414	$	(488	)

As of October 1, 2017, the Company did not recognize any other-than-temporary impairment of these investments. In its evaluation, management considered the type of security, the credit rating of the security, the length of time the security has been in a loss position, the size of the loss position, the Company's intent and ability to hold the security to expected recovery of value, and other meaningful information. The Company does not intend to sell, and is unlikely to be required to sell, any of these available-for-sale investments before their effective maturity or market price recovery.

The Company recorded gross realized gains and gross realized losses on the sale of debt securities totaling $306,000 and $43,000, respectively, during the three-month period ended October 1, 2017 and $55,000 and $0, respectively, during the three-month period ended October 2, 2016. The Company recorded gross realized gains and gross realized losses on the sale of debt securities totaling $449,000 and $79,000, respectively, during the nine-month period ended October 1, 2017 and $280,000 and $97,000, respectively, during the nine-month period ended October 2, 2016. These gains and losses are included in "Investment income" on the Consolidated Statement of Operations. Prior to the sale of these securities, unrealized gains and losses for these debt securities, net of tax, are recorded in shareholders’ equity as other comprehensive income (loss).

The following table presents the effective maturity dates of the Company’s available-for-sale investments as of October 1, 2017 (in thousands):



	<1 year		1-2 Years		2-3 Years		3-4 Years		4-5 Years		5-7 Years		Total
Corporate bonds	$	65,569	$	109,918	$	77,430	$	17,223	$	39,956	$	1,413	$	311,509
Treasury bills	70,184		63,602		—		—		—		—		133,786
Asset-backed securities	47,840		35,502		16,075		—		2,328		5,164		106,909
Euro liquidity fund	52,312		—		—		—		—		—		52,312
Sovereign bonds	20,945		4,599		3,427		—		—		—		28,971
Agency bonds	7,606		2,719		—		—		2,920		—		13,245
Municipal bonds	8,805		2,869		1,356		—		—		—		13,030
	$	273,261	$	219,209	$	98,288	$	17,223	$	45,204	$	6,577	$	659,762