Marketable Securities (Tables)

3 Months Ended

Mar. 31, 2021

Investments Debt And Equity Securities [Abstract]

Summary of Held-to-Maturity Marketable Securities

The amortized cost, unrealized gains and losses and estimated fair value of the Company’s held-to-maturity marketable securities as of March 31, 2021 and December 31, 2020 were as follows:

	March 31, 2021
	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
	(in thousands)
Cash and cash equivalents
Commercial paper	$	12,858	$	—	$	(3	)	$	12,855
Short-term investments
Commercial paper		50,203		—		(32	)		50,171
Corporate bonds		5,621		—		(1	)		5,620
Total	$	68,682	$	—	$	(36	)	$	68,646

	December 31, 2020
	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
	(in thousands)
Cash and cash equivalents
Commercial paper	$	15,498	$	—	$	(3	)	$	15,495
Short-term investments
Commercial paper		46,978		—		(33	)		46,945
Corporate bonds		6,148		1		(1	)		6,148
Total	$	68,624	$	1	$	(37	)	$	68,588

Summary of Continuous Unrealized Loss on Marketable Securities

The gross unrealized losses, estimated fair value and length of time the individual marketable securities were in a continuous loss position for those marketable securities in an unrealized loss position as of March 31, 2021 and December 31, 2020 were as follows:

	March 31, 2021
	Less Than 12 Months					12 Months or Greater				Total
	Estimated Fair Value		Unrealized Loss			Estimated Fair Value		Unrealized Loss		Estimated Fair Value		Unrealized Loss
	(in thousands)
Commercial paper	$	63,026	$	(35	)	$	—	$	—	$	63,026	$	(35	)
Corporate bonds		4,119		(1	)		—		—		4,119		(1	)
Total	$	67,145	$	(36	)	$	—	$	—	$	67,145	$	(36	)

	December 31, 2020
	Less Than 12 Months					12 Months or Greater				Total
	Estimated Fair Value		Unrealized Loss			Estimated Fair Value		Unrealized Loss		Estimated Fair Value		Unrealized Loss
	(in thousands)
Commercial paper	$	62,440	$	(36	)	$	—	$	—	$	62,440	$	(36	)
Corporate bonds		4,569		(1	)		—		—		4,569		(1	)
Total	$	67,009	$	(37	)	$	—	$	—	$	67,009	$	(37	)