Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2022

Fair Value Disclosures [Abstract]

Summary of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis

The tables below present information about our assets and liabilities that are measured and carried at fair value on a recurring basis and indicate the level within the fair value hierarchy we utilized to determine such fair values:

As of June 30, 2022 (In thousands)	Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Cash equivalents
Money market funds	$	133,202	$	—	$	—	$	133,202
Commercial paper		—		4,999		—		4,999
Marketable securities (current)
U.S. government treasuries		211,135		—		—		211,135
Corporate debt securities		—		8,958		—		8,958
Commercial paper		—		172,897		—		172,897
Restricted cash
Money market funds		1,867		—		—		1,867
Total assets	$	346,204	$	186,854	$	—	$	533,058
Liabilities:
Financing liability, related party		—		—		27,205		27,205
Financing liability		—		—		27,205		27,205
Total liabilities	$	—	$	—	$	54,410	$	54,410

As of December 31, 2021 (In thousands)	Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Cash equivalents
Money market funds	$	153,589	$	—	$	—	$	153,589
Corporate debt securities		—		1,431		—		1,431
Commercial paper		—		37,998		—		37,998
Marketable securities (current)
U.S. government treasuries		171,063		—		—		171,063
Corporate debt securities		—		20,452		—		20,452
Commercial paper		—		181,155		—		181,155
Marketable securities (non-current)
U.S. government treasuries		52,269		—		—		52,269
Restricted cash
Money market funds		4,200		—		—		4,200
Total assets	$	381,121	$	241,036	$	—	$	622,157
Liabilities:
Financing liability, related party		—		—		16,770		16,770
Financing liability		—		—		16,770		16,770
Total liabilities	$	—	$	—	$	33,540	$	33,540

Summary of Estimated Fair Value and Amortized Cost of Available-for-Sale Marketable Debt Securities

The estimated fair value and amortized cost of our available-for-sale marketable debt securities, by contractual maturity and security type, are summarized as follows:

As of June 30, 2022 (In thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Due in one year or less
U.S. government treasuries	$	212,366	$	17	$	(1,248	)	$	211,135
Corporate debt securities		9,004		—		(46	)		8,958
Commercial paper		173,675		12		(790	)		172,897
Total marketable securities	$	395,045	$	29	$	(2,084	)	$	392,990

As of December 31, 2021 (In thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Due in one year or less
U.S. government treasuries	$	171,111	$	—	$	(48	)	$	171,063
Corporate debt securities		20,464		—		(12	)		20,452
Commercial paper		181,176		11		(32	)		181,155
Due after one year through two years
U.S. government treasuries		52,387		—		(118	)		52,269
Total marketable securities	$	425,138	$	11	$	(210	)	$	424,939

Summary of Rollforward of the Liability Associated with Financing Liabilities

The following table provides a rollforward of the liability associated with our financing liabilities:

	For the Six Months Ended June 30,
(In thousands)	2022
Beginning liability balance	$	33,540
Funding commitment received		37,500
Change in fair value recognized in other expense (income), net		(5,800	)
Change in fair value attributable to instrument-specific credit risk recognized in other comprehensive (income) loss		(10,830	)
Ending liability balance	$	54,410