Fair Value Measurements (Tables)

3 Months Ended

Mar. 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 March 31, 2022 and December 31, 2021.

	March 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	$	170,827	$	170,827	$	—	$	—
International commercial paper		4,000		—		4,000		—
U.S. corporate bonds		2,721		—		2,721		—
Total cash equivalents		177,548		170,827		6,721		—
Marketable securities:
U.S. government securities		436,464		—		436,464		—
U.S. corporate bonds		568,109		—		568,109		—
International corporate bonds		200,209		—		200,209		—
U.S. commercial paper		75,228		—		75,228		—
International commercial paper		129,587		—		129,587		—
U.S. municipal securities		36,970		—		36,970		—
Total marketable securities		1,446,567		—		1,446,567		—
	$	1,624,115	$	170,827	$	1,453,288	$	—

	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 March 31, 2022 and December 31, 2021:

	March 31, 2022
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Credit Losses		Fair Value
	(in thousands)
Assets:
U.S. government securities	$	441,082	$	3	$	(4,621	)	$	—	$	436,464
U.S. corporate bonds		572,189		10		(4,090	)		—		568,109
International corporate bonds		202,003		—		(1,794	)		—		200,209
U.S. commercial paper		75,309		—		(81	)		—		75,228
International commercial paper		129,703		—		(116	)		—		129,587
U.S. municipal securities		37,482		—		(512	)		—		36,970
	$	1,457,768	$	13	$	(11,214	)	$	—	$	1,446,567

	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