Available-for-Sale Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2020

Investments Debt And Equity Securities [Abstract]

Summary of Available-for-Sale Marketable Securities by Major Type of Security

The following tables summarize the Company’s available-for-sale marketable securities by major type of security as of December 31, 2020 and 2019:

As of December 31, 2020

			Gross Unrealized				Estimated Fair
Type of Security	Amortized Cost		Gains		Losses		Value
U.S. Treasury securities	$	20,710	$	41	$	(1)	$	20,750
U.S. government agency obligations		22,125		4		(1)		22,128
Corporate bonds		49,080		61		(23)		49,118
Commercial paper		116,139		5		(17)		116,127
Municipal bonds		11,680		12		(8)		11,684
Total available-for-sale marketable securities	$	219,734	$	123	$	(50)	$	219,807

As of December 31, 2019

			Gross Unrealized				Estimated Fair
Type of Security	Amortized Cost		Gains		Losses		Value
U.S. Treasury securities	$	16,052	$	31	$	(2)	$	16,081
U.S. government agency obligations		25,803		14		(1)		25,816
Corporate bonds		115,788		125		(23)		115,890
Commercial paper		38,547		27		(1)		38,573
Municipal bonds		3,500		—		—		3,500
Total available-for-sale marketable securities	$	199,690	$	197	$	(27)	$	199,860

Schedule of Fair Values and Continuous Unrealized Loss Positions of Available-for-Sale Marketable Securities

The following tables summarize the fair value and gross unrealized losses of the Company’s available-for-sale marketable securities by investment category and disaggregated by the length of time that individual debt securities have been in a continuous unrealized loss position as of December 31, 2020 and 2019:

As of December 31, 2020

	Less than 12 Months				12 Months or Greater				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses
U.S. Treasury securities	$	12,682	$	(1)	$	—	$	—	$	12,682	$	(1)
U.S. government agency obligations		2,500		(1)		—		—		2,500		(1)
Corporate bonds		23,553		(23)		—		—		23,553		(23)
Commercial paper		68,897		(17)		—		—		68,897		(17)
Municipal bonds		6,259		(8)		—		—		6,259		(8)
Total	$	113,891	$	(50)	$	—	$	—	$	113,891	$	(50)

As of December 31, 2019

	Less than 12 Months				12 Months or Greater				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses
U.S. Treasury securities	$	3,185	$	(2)	$	—	$	—	$	3,185	$	(2)
U.S. government agency obligations		2,400		(1)		—		—		2,400		(1)
Corporate bonds		28,895		(23)		—		—		28,895		(23)
Commercial paper		4,264		(1)		—		—		4,264		(1)
Total	$	38,744	$	(27)	$	—	$	—	$	38,744	$	(27)

Schedule of Amortized Cost and Fair Values of Marketable Debt Securities by Contractual Maturity

The Company classifies its marketable debt securities based on their contractual maturity dates. As of December 31, 2020, the Company’s marketable debt securities mature at various dates through December 2023. The amortized cost and fair values of marketable debt securities by contractual maturity were as follows:

	As of December 31, 2020				As of December 31, 2019
Contractual maturity	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Less than one year	$	149,164	$	149,242	$	136,565	$	136,701
One year to three years		70,570		70,565		63,125		63,159
Total	$	219,734	$	219,807	$	199,690	$	199,860