Marketable Securities - Summary of Cash Equivalents and Marketable Securities Recorded at Fair Value (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Marketable Securities [Line Items]
Cash equivalents, amortized cost	$ 113,561	$ 517,383
Cash equivalents, gross unrealized gains	3
Cash equivalents, gross unrealized losses	(7)	(1)
Cash equivalents, fair value	113,557	517,382
Marketable securities, amortized cost	1,597,081	1,461,200
Marketable securities, gross unrealized gains	15	16
Marketable securities, gross unrealized losses	(20,258)	(5,118)
Marketable securities, fair value	1,576,838	1,456,098
Cash equivalents and marketable securities, amortized cost	1,710,642	1,978,583
Cash equivalents and marketable securities, gross unrealized gains	18	16
Cash equivalents and marketable securities, gross unrealized losses	(20,265)	(5,119)
Cash equivalents and marketable securities, fair value	1,690,395	1,973,480
Money Market Funds [Member]
Marketable Securities [Line Items]
Cash equivalents, amortized cost	21,287	507,386
Cash equivalents, fair value	21,287	507,386
Certificates of Deposit [Member]
Marketable Securities [Line Items]
Cash equivalents, amortized cost	5,007
Cash equivalents, fair value	5,007
Marketable securities, amortized cost	45,654	45,164
Marketable securities, fair value	45,654	45,164
Commercial Paper [Member]
Marketable Securities [Line Items]
Cash equivalents, amortized cost	72,250	9,997
Cash equivalents, gross unrealized losses		(1)
Cash equivalents, fair value	72,250	9,996
Marketable securities, amortized cost	364,859	212,805
Marketable securities, gross unrealized losses	(756)	(86)
Marketable securities, fair value	364,103	212,719
US Treasury Securities [Member]
Marketable Securities [Line Items]
Cash equivalents, amortized cost	1,207
Cash equivalents, fair value	1,207
Marketable securities, amortized cost	9,962	16,238
Marketable securities, gross unrealized gains		6
Marketable securities, gross unrealized losses	(16)	(52)
Marketable securities, fair value	9,946	16,192
Corporate Debt Securities [Member]
Marketable Securities [Line Items]
Cash equivalents, amortized cost	13,810
Cash equivalents, gross unrealized gains	3
Cash equivalents, gross unrealized losses	(7)
Cash equivalents, fair value	13,806
Marketable securities, amortized cost	1,144,291	1,173,659
Marketable securities, gross unrealized gains	15	10
Marketable securities, gross unrealized losses	(18,852)	(4,903)
Marketable securities, fair value	1,125,454	1,168,766
Government-sponsored Enterprise Securities [Member]
Marketable Securities [Line Items]
Marketable securities, amortized cost	32,315	13,334
Marketable securities, gross unrealized losses	(634)	(77)
Marketable securities, fair value	$ 31,681	$ 13,257