Cash, Cash Equivalents, and Investments (Tables)

6 Months Ended

Jun. 28, 2020

Cash and Cash Equivalents [Abstract]

Components of Cash, Cash Equivalents, and Investments

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

	June 28, 2020		December 31, 2019
Cash	$	235,799	$	155,498
Money market instruments	50,222		15,933
Cash and cash equivalents	286,021		171,431
Asset-backed securities	50,311		66,680
Corporate bonds	42,248		65,624
Treasury bills	34,018		92,914
Sovereign bonds	14,869		6,294
Municipal bonds	1,638		4,630
Certificate of deposit	—		4,328
Current investments	143,084		240,470
Treasury bills	196,674		216,334
Corporate bonds	194,412		146,474
Asset-backed securities	41,299		46,403
Agency bonds	22,054		5,914
Sovereign bonds	12,648		16,005
Municipal bonds	—		2,322
Non-current investments	467,087		433,452
	$	896,192	$	845,353

Summary of Available-for-Sale Investments

The following table summarizes the Company’s available-for-sale investments as of June 28, 2020 (in thousands):

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Current:
Asset-backed securities	$	49,899	$	412	$	—	$	50,311
Corporate bonds	42,065		221		(38)		42,248
Treasury bills	33,480		538		—		34,018
Sovereign bonds	14,787		82		—		14,869
Municipal bonds	1,643		—		(5)		1,638
Non-current:
Treasury bills	194,330		2,345		(1)		196,674
Corporate bonds	192,233		2,513		(334)		194,412
Asset-backed securities	40,817		484		(2)		41,299
Agency bonds	22,035		37		(18)		22,054
Sovereign bonds	12,533		115		—		12,648
	$	603,822	$	6,747	$	(398)	$	610,171

Gross Unrealized Losses and Fair Values for Available-for-Sale Investments

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 June 28, 2020 (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
Corporate bonds	$	49,525	$	(363)	$	1,181	$	(9)	$	50,706	$	(372)
Treasury bills	12,962		(1)		—		—		12,962		(1)
Asset-backed securities	5,749		(1)		260		(1)		6,009		(2)
Agency bonds	3,128		(2)		2,784		(16)		5,912		(18)
Municipal bonds	1,293		(5)		—		—		1,293		(5)
	$	72,657	$	(372)	$	4,225	$	(26)	$	76,882	$	(398)

Schedule of Allowance for Credit Loss Activity

The following table summarizes the allowance for credit losses activity for the six-month period ended June 28, 2020 (in thousands):

Balance as of December 31, 2019	$	—
Increases to the allowance for credit losses	160
Decreases to the allowance for credit losses	(85)
Write-offs	—
Balance as of June 28, 2020	$	75

Effective Maturity Dates of Available-for-Sale Investments

The following table presents the effective maturity dates of the Company’s available-for-sale investments as of June 28, 2020 (in thousands):

	<1 year		1-2 Years		2-3 Years		3-4 Years		4-5 Years		Total
Corporate bonds	$	42,248	$	81,987	$	102,034	$	10,391	$	—	$	236,660
Treasury bills	34,018		138,612		58,062		—		—		230,692
Asset-backed securities	50,311		13,750		23,308		—		4,241		91,610
Sovereign bonds	14,869		9,218		3,430		—		—		27,517
Agency bonds	—		—		22,054		—		—		22,054
Municipal bonds	1,638		—		—		—		—		1,638
	$	143,084	$	243,567	$	208,888	$	10,391	$	4,241	$	610,171