Fair Value of Financial Instruments (Tables)

6 Months Ended

Jun. 29, 2019

Summary of valuation of the financial instruments

The following summarizes the valuation of the Company’s financial instruments (in thousands). The tables do not include either cash on hand or assets and liabilities that are measured at historical cost or any basis other than fair value.

	Fair Value Measurements
	at June 29, 2019 Using
	Quoted Prices in		Significant Other		Significant
	Active Markets for		Observable		Unobservable
	Identical Assets		Inputs		Inputs
Description	(Level 1)		(Level 2)		(Level 3)		Total
Assets:
Cash equivalents:
Money market funds	$	84,467	$	—	$	—	$	84,467
Corporate debt securities		—		11,626		—		11,626
Total cash equivalents	$	84,467	$	11,626	$	—	$	96,093
Short-term investments:
Government debt securities	$	72,422	$	93,899	$	—	$	166,321
Corporate debt securities		—		285,944		—		285,944
Total short-term investments	$	72,422	$	379,843	$	—	$	452,265
Other assets, net:
Auction rate securities	$	—	$	—	$	5,647	$	5,647
Total	$	—	$	—	$	5,647	$	5,647
Total	$	156,889	$	391,469	$	5,647	$	554,005

	Fair Value Measurements
	at December 29, 2018 Using
	Quoted Prices in		Significant Other		Significant
	Active Markets for		Observable		Unobservable
	Identical Assets		Inputs		Inputs
Description	(Level 1)		(Level 2)		(Level 3)		Total
Assets:
Cash equivalents:
Money market funds	$	74,990	$	—	$	—	$	74,990
Corporate debt securities		—		18,820		—		18,820
Government debt securities		9,338		—		—		9,338
Total cash equivalents	$	84,328	$	18,820	$	—	$	103,148
Short-term investments:
Government debt securities	$	48,141	$	99,211	$	—	$	147,352
Corporate debt securities		—		269,427		—		269,427
Total short-term investments	$	48,141	$	368,638	$	—	$	416,779
Other assets, net:
Auction rate securities	$	—	$	—	$	5,759	$	5,759
Total	$	—	$	—	$	5,759	$	5,759
Total	$	132,469	$	387,458	$	5,759	$	525,686

Schedule of maturities of the Company's available-for-sale investments

The following summarizes the contractual underlying maturities of the Company’s available-for-sale investments at June 29, 2019 (in thousands):

			Fair
	Cost		Value
Due in one year or less	$	394,836	$	395,419
Due after one year through ten years		144,592		145,639
Due after ten years		13,300		12,947
	$	552,728	$	554,005

Schedule of available-for-sale investments in continuous unrealized loss position by length of time

The available-for-sale investments that were in a continuous unrealized loss position, aggregated by length of time that individual securities have been in a continuous loss position, were as follows (in thousands):

	Less Than 12 Months				12 Months or Greater				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
As of June 29, 2019	Value		Losses		Value		Losses		Value		Losses
Government debt securities	$	12,126	$	(6)	$	58,758	$	(98)	$	70,884	$	(104)
Corporate debt securities		1,575		(1)		33,026		(45)		34,601		(46)
Auction rate securities		—		—		5,647		(353)		5,647		(353)
	$	13,701	$	(7)	$	97,431	$	(496)	$	111,132	$	(503)

	Less Than 12 Months				12 Months or Greater				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
As of December 29, 2018	Value		Losses		Value		Losses		Value		Losses
Government debt securities	$	13,278	$	(10)	$	88,696	$	(583)	$	101,974	$	(593)
Corporate debt securities		112,699		(273)		76,310		(448)		189,009		(721)
Auction rate securities		—		—		5,759		(241)		5,759		(241)
	$	125,977	$	(283)	$	170,765	$	(1,272)	$	296,742	$	(1,555)

Summary of quantitative information about level 3 fair value measurements

Auction rate securities

Fair Value at
June 29, 2019
(000s)		Valuation Technique	Unobservable Input	Weighted Average
$	5,647	Discounted cash flow	Estimated yield	3.38%
			Expected holding period	10 years
			Estimated discount rate	3.10%

Summary of activity in Level 3 financial instruments

The following summarizes the activity in Level 3 financial instruments for the three and six months ended June 29, 2019 (in thousands):

Assets
	Three Months		Six Months
Auction Rate Securities	Ended		Ended
Beginning balance	$	5,761	$	5,759
Loss included in other comprehensive income (loss)		(114)		(112)
Balance at June 29, 2019	$	5,647	$	5,647