Marketable Securities - Summary of Available -for-sale Marketable Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Marketable Securities [Line Items]
Amortized Cost	$ 964,768	$ 437,350
Gross Unrealized Gains		23
Gross Unrealized Losses	(2,125)	(22)
Estimated Fair Value	962,643	437,351
U.S. Treasury and Other Government Securities [Member]
Marketable Securities [Line Items]
Amortized Cost	301,493
Gross Unrealized Losses	(1,016)
Estimated Fair Value	300,477
Financial Institution Debt Securities [Member]
Marketable Securities [Line Items]
Amortized Cost	441,068	138,445
Gross Unrealized Gains		6
Gross Unrealized Losses	(652)	(8)
Estimated Fair Value	440,416	138,443
Corporate Debt Securities [Member]
Marketable Securities [Line Items]
Amortized Cost	62,500	41,765
Gross Unrealized Gains		3
Gross Unrealized Losses	(151)	(2)
Estimated Fair Value	62,349	41,766
Other Asset Backed Securities [Member]
Marketable Securities [Line Items]
Amortized Cost	159,707	11,474
Gross Unrealized Gains		1
Gross Unrealized Losses	(306)	(1)
Estimated Fair Value	$ 159,401	11,474
U.S. Treasury Securities [Member]
Marketable Securities [Line Items]
Amortized Cost		245,666
Gross Unrealized Gains		13
Gross Unrealized Losses		(11)
Estimated Fair Value		$ 245,668

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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