Fair Value Measurements - Summary of Gross Unrealized Gains and Losses of Marketable Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 1,450,723	$ 438,052
Gross Unrealized Gains	27	451
Gross Unrealized Losses	(2,687)	(36)
Fair Value	1,448,063	438,467
U.S. Government Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	325,514	160,589
Gross Unrealized Gains		11
Gross Unrealized Losses	(982)	(12)
Fair Value	324,532	160,588
U.S. Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	628,836	122,882
Gross Unrealized Gains	27	240
Gross Unrealized Losses	(1,083)	(15)
Fair Value	627,780	123,107
International Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	237,303	57,485
Gross Unrealized Gains		200
Gross Unrealized Losses	(491)	(9)
Fair Value	236,812	57,676
U.S. Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	80,194	45,963
Gross Unrealized Losses	(18)
Fair Value	80,176	45,963
International Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	142,358	51,133
Gross Unrealized Losses	(23)
Fair Value	142,335	$ 51,133
U.S. Municipal Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	36,518
Gross Unrealized Losses	(90)
Fair Value	$ 36,428

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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