Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2022

Investments, Debt and Equity Securities [Abstract]

Summary of Marketable Securities

The following is a summary of marketable securities at June 30, 2022 and December 31, 2021 (in thousands):

	June 30, 2022
	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Allowance for Credit Losses		Estimated Fair Values
Marketable securities
Corporate bonds and notes	$	5,339	$	—	$	(18	)	$	—	$	5,321
Commercial paper		23,385		—		(32	)		—		23,353
Total debt securities		28,724		—		(50	)		—		28,674
Money market funds	$	3,949		—		—			—		3,949
Total equity securities		3,949		—		—			—		3,949
Total marketable securities	$	32,673	$	—	$	(50	)	$	—	$	32,623
Reported in:
Cash and cash equivalents										$	22,128
Available-for-sale debt securities										$	10,495
Total marketable securities										$	32,623

	December 31, 2021
	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Allowance for Credit losses		Estimated Fair Values
Marketable securities
Corporate bonds and notes	$	40,466	$	—	$	(53	)	$	—	$	40,413
Commercial paper		49,609		—		(18	)		—		49,591
Total debt securities		90,075		—		(71	)		—		90,004
Money market funds		12,372		—		—			—		12,372
Total equity securities		12,372		—		—			—		12,372
Total marketable securities	$	102,447	$	—	$	(71	)	$	—	$	102,376
Reported in:
Cash and cash equivalents										$	41,842
Available-for-sale debt securities											60,534
Total marketable securities										$	102,376

Fair Value and Gross Unrealized Losses Related to Individual Available-for-Sale Debt Securities

The following table summarizes the fair value and gross unrealized losses related to individual AFS debt securities at June 30, 2022 and December 31, 2021, which have been in a continuous unrealized loss position, aggregated by investment category and length of time (in thousands):

	Less Than 12 Months					12 Months or More					Total					Fair Value
June 30, 2022	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Cash and Cash Equivalents		AFS Debt Securities
Corporate bonds and notes	$	—	$	—		$	5,321	$	(18	)	$	5,321	$	(18	)	$	—	$	5,321
Commercial paper		23,353		(32	)		—		—			23,353		(32	)		18,179		5,174
Total	$	23,353	$	(32	)	$	5,321	$	(18	)	$	28,674	$	(50	)	$	18,179	$	10,495

	Less Than 12 Months					12 Months or More					Total					Fair Value
December 31, 2021	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Cash and Cash Equivalents		AFS Debt Securities
Corporate bonds and notes	$	29,807	$	(45	)	$	10,382	$	(8	)	$	40,189	$	(53	)	$	—	$	40,189
Commercial paper		48,091		(18	)		—		—			48,091		(18	)		29,470		18,621
Total	$	77,898	$	(63	)	$	10,382	$	(8	)	$	88,280	$	(71	)	$	29,470	$	58,810

Estimated Fair Value of Marketable Debt Securities by Contractual Maturity

The estimated fair value of marketable debt securities by contractual maturity at June 30, 2022 is shown below (in thousands). Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations without penalties.

	Estimated Fair Value
Due in one year or less	$	28,674
Due in one to two years		-
Total	$	28,674