Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 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 June 30, 2022 and December 31, 2021.

	June 30, 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	$	202,519	$	202,519	$	—	$	—
International corporate bonds		2,599		—		2,599		—
Total cash equivalents		205,118		202,519		2,599		—
Marketable securities:
U.S. government securities		402,639		—		402,639		—
U.S. corporate bonds		494,017		—		494,017		—
International corporate bonds		165,396		—		165,396		—
U.S. commercial paper		74,037		—		74,037		—
International commercial paper		113,854		—		113,854		—
U.S. certificates of deposit		19,981		—		19,981		—
U.S. municipal securities		37,273		—		37,273		—
Total marketable securities		1,307,197		—		1,307,197		—
	$	1,512,315	$	202,519	$	1,309,796	$	—

	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 June 30, 2022 and December 31, 2021:

	June 30, 2022
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Credit Losses		Fair Value
	(in thousands)
Assets:
U.S. government securities	$	408,463	$	19	$	(5,843	)	$	—	$	402,639
U.S. corporate bonds		498,829		3		(4,815	)		—		494,017
International corporate bonds		167,534		—		(2,138	)		—		165,396
U.S. commercial paper		74,170		—		(133	)		—		74,037
International commercial paper		114,107		—		(253	)		—		113,854
U.S. certificates of deposit		19,981		—		—			—		19,981
U.S. municipal securities		37,985		—		(712	)		—		37,273
	$	1,321,069	$	22	$	(13,894	)	$	—	$	1,307,197

	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 are in a loss position as of June 30, 2022 and December 31, 2021:

	June 30, 2022
	Less than 12 months					Greater than 12 months					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
U.S. government securities	$	400,161	$	(5,843	)	$	—	$	—		$	400,161	$	(5,843	)
U.S. corporate bonds		449,691		(4,471	)		27,924		(344	)		477,615		(4,815	)
International corporate bonds		145,479		(1,940	)		21,960		(198	)		167,439		(2,138	)
U.S. commercial paper		30,689		(133	)		—		—			30,689		(133	)
International commercial paper		36,487		(253	)		—		—			36,487		(253	)
U.S. certificates of deposit		—		—			—		—			—		—
U.S. municipal securities		34,273		(712	)		—		—			34,273		(712	)
	$	1,096,780	$	(13,352	)	$	49,884	$	(542	)	$	1,146,664	$	(13,894	)

	December 31, 2021
	Less than 12 months					Greater than 12 months				Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
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	)