Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2022

Fair Value Disclosures [Abstract]

Summary of Company's Cash Equivalents and Marketable Securities

The following tables summarize the Company’s cash equivalents and marketable securities as of December 31, 2022 and 2021:

	December 31, 2022
	Total		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(in thousands)
Cash equivalents:
Money market funds	$	161,185	$	161,185	$	—	$	—
Total cash equivalents		161,185		161,185		—		—
Marketable securities:
U.S. government securities		302,911		—		302,911		—
U.S. corporate bonds		354,495		—		354,495		—
International corporate bonds		127,248		—		127,248		—
U.S. commercial paper		63,114		—		63,114		—
International commercial paper		133,163		—		133,163		—
U.S. certificates of deposit		15,613		—		15,613		—
U.S. municipal securities		113,250		—		113,250		—
Total marketable securities		1,109,794		—		1,109,794		—
	$	1,270,979	$	161,185	$	1,109,794	$	—

	December 31, 2021
	Total		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(in thousands)
Cash equivalents:
Money market funds	$	289,440	$	289,440	$	—	$	—
U.S. commercial paper		2,000		—		2,000		—
International commercial paper		1,999		—		1,999		—
Total cash equivalents		293,439		289,440		3,999		—
Marketable securities:
U.S. government securities		324,532		—		324,532		—
U.S. corporate bonds		627,780		—		627,780		—
International corporate bonds		236,812		—		236,812		—
U.S. commercial paper		80,176		—		80,176		—
International commercial paper		142,335		—		142,335		—
U.S. municipal securities		36,428		—		36,428		—
Total marketable securities		1,448,063		—		1,448,063		—
	$	1,741,502	$	289,440	$	1,452,062	$	—

Summary of Gross Unrealized Gains and Losses of Marketable Securities

The following tables summarize the gross unrealized gains and losses of the Company’s marketable securities as of December 31, 2022 and 2021:

	December 31, 2022
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Credit Losses		Fair Value
	(in thousands)
Assets:
U.S. government securities	$	307,173	$	—	$	(4,262	)	$	—	$	302,911
U.S. corporate bonds		358,019		6		(3,530	)		—		354,495
International corporate bonds		128,374		7		(1,133	)		—		127,248
U.S. commercial paper		63,234		—		(120	)		—		63,114
International commercial paper		133,338		—		(175	)		—		133,163
U.S. certificates of deposit		15,613		—		—			—		15,613
U.S. municipal securities		114,249		31		(1,030	)		—		113,250
	$	1,120,000	$	44	$	(10,250	)	$	—	$	1,109,794

	December 31, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Credit Losses		Fair Value
	(in thousands)
Assets:
U.S. government securities	$	325,514	$	—	$	(982	)	$	—	$	324,532
U.S. corporate bonds		628,836		27		(1,083	)		—		627,780
International corporate bonds		237,303		—		(491	)		—		236,812
U.S. commercial paper		80,194		—		(18	)		—		80,176
International commercial paper		142,358		—		(23	)		—		142,335
U.S. municipal securities		36,518		—		(90	)		—		36,428
	$	1,450,723	$	27	$	(2,687	)	$	—	$	1,448,063

Summary of Fair Value And Unrealized Losses of Marketable Securities In Loss Position

The following tables summarize the fair value and the unrealized losses of the Company’s marketable securities that have been in a loss position for either less than twelve months or greater than twelve months as of December 31, 2022 and 2021:

	December 31, 2022
	Less than 12 months					Greater than 12 months					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
	(in thousands)
U.S. government securities	$	112,243	$	(1,517	)	$	185,691	$	(2,745	)		297,934	$	(4,262	)
U.S. corporate bonds		208,507		(1,989	)		130,633		(1,541	)		339,140		(3,530	)
International corporate bonds		50,982		(497	)		68,993		(636	)		119,975		(1,133	)
U.S. commercial paper		24,768		(120	)		—		—			24,768		(120	)
International commercial paper		30,987		(175	)		—		—			30,987		(175	)
U.S. municipal securities		86,251		(497	)		14,466		(533	)		100,717		(1,030	)
	$	513,738	$	(4,795	)	$	399,783	$	(5,455	)	$	913,521	$	(10,250	)

	December 31, 2021
	Less than 12 months					Greater than 12 months				Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
	(in thousands)
U.S. government securities	$	309,588	$	(982	)	$	—	$	—	$	309,588	$	(982	)
U.S. corporate bonds		601,475		(1,083	)		—		—		601,475		(1,083	)
International corporate bonds		231,672		(491	)		—		—		231,672		(491	)
U.S. commercial paper		21,968		(18	)		—		—		21,968		(18	)
International commercial paper		35,059		(23	)		—		—		35,059		(23	)
U.S. municipal securities		24,953		(90	)		—		—		24,953		(90	)
	$	1,224,715	$	(2,687	)	$	—	$	—	$	1,224,715	$	(2,687	)