Fair Value Measurements - Summary of Gross Unrealized Gains and Losses of Marketable Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 1,457,768	$ 1,450,723
Gross Unrealized Gains	13	27
Gross Unrealized Losses	(11,214)	(2,687)
Fair Value	1,446,567	1,448,063
U.S. Government Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	441,082	325,514
Gross Unrealized Gains	3
Gross Unrealized Losses	(4,621)	(982)
Fair Value	436,464	324,532
U.S. Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	572,189	628,836
Gross Unrealized Gains	10	27
Gross Unrealized Losses	(4,090)	(1,083)
Fair Value	568,109	627,780
International Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	202,003	237,303
Gross Unrealized Losses	(1,794)	(491)
Fair Value	200,209	236,812
U.S. Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	75,309	80,194
Gross Unrealized Losses	(81)	(18)
Fair Value	75,228	80,176
International Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	129,703	142,358
Gross Unrealized Losses	(116)	(23)
Fair Value	129,587	142,335
U.S. Municipal Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	37,482	36,518
Gross Unrealized Losses	(512)	(90)
Fair Value	$ 36,970	$ 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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