Marketable Securities - (Tables)

3 Months Ended

Mar. 28, 2020

Schedule of Marketable Securities by Category

At March 28, 2020 and December 31, 2019, marketable securities are categorized as follows:

	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Fair Value
March 28, 2020
Municipal notes and bonds	$	70,499	$	296	$	10	$	70,785
Asset-backed securities		12,216		2		59		12,159
Certificates of deposit		33,154		13		262		32,905
Commercial paper		42,511		1		66		42,446
Corporate bonds		32,507		6		179		32,334
Total marketable securities	$	190,887	$	318	$	576	$	190,629
December 31, 2019
Municipal notes and bonds	$	80,926	$	188	$	6	$	81,108
Asset-backed securities		10,767		12		—		10,779
Certificates of deposit		30,500		7		—		30,507
Commercial paper		30,707		1		—		30,708
Corporate bonds		36,409		52		—		36,461
Total marketable securities	$	189,309	$	260	$	6	$	189,563

Schedule of Amortized Cost and Estimated Fair Value of Marketable Securities Classified by Maturity Date

The amortized cost and estimated fair value of marketable securities classified by the maturity date listed on the security, regardless of the Condensed Consolidated Balance Sheets classification, is as follows at March 28, 2020 and December 31, 2019:

	March 28, 2020				December 31, 2019
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Due within one year	$	155,514	$	155,462	$	152,649	$	152,852
Due after one through five years		35,373		35,167		36,660		36,711
Due after five through ten years		—		—		—		—
Due after ten years		—		—		—		—
Total marketable securities	$	190,887	$	190,629	$	189,309	$	189,563

Summary of Estimated Fair Value and Gross Unrealized Holding Losses of Marketable Securities in Unrealized Loss Position

The following table summarizes the estimated fair value and gross unrealized holding losses of marketable securities, aggregated by investment instrument and period of time in an unrealized loss position, at March 28, 2020 and December 31, 2019:

	In Unrealized Loss Position For Less Than 12 Months				In Unrealized Loss Position For Greater Than 12 Months
	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
March 28, 2020
Municipal notes and bonds	$	5,086	$	10	$	—	$	—
Asset-backed securities		10,978		59		—		—
Certificates of deposit		23,841		262		—		—
Commercial paper		22,457		66		—		—
Corporate bonds		25,458		179		—		—
Total	$	87,820	$	576	$	—	$	—
December 31, 2019
Municipal notes and bonds	$	14,166	$	6	$	—	$	—
Total	$	14,166	$	6	$	—	$	—