Marketable Securities - Summary of Available -for-sale Marketable Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Marketable Securities [Line Items]
Amortized Cost	$ 714,727	$ 964,768
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(7,194)	(2,125)
Estimated Fair Value	707,533	962,643
U.S. Treasury and Other Government Securities [Member]
Marketable Securities [Line Items]
Amortized Cost	295,367	301,493
Gross Unrealized Gains		0
Gross Unrealized Losses	(3,840)	(1,016)
Estimated Fair Value	291,527	300,477
Financial Institution Debt Securities [Member]
Marketable Securities [Line Items]
Amortized Cost	327,417	441,068
Gross Unrealized Gains		0
Gross Unrealized Losses	(2,154)	(652)
Estimated Fair Value	325,263	440,416
Corporate Debt Securities [Member]
Marketable Securities [Line Items]
Amortized Cost	67,018	62,500
Gross Unrealized Gains		0
Gross Unrealized Losses	(772)	(151)
Estimated Fair Value	66,246	62,349
Other Asset Backed Securities [Member]
Marketable Securities [Line Items]
Amortized Cost	24,925	159,707
Gross Unrealized Gains		0
Gross Unrealized Losses	(428)	(306)
Estimated Fair Value	$ 24,497	$ 159,401

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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