Investment Securities - Summary of Investment Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	$ 396,234	$ 412,570
Unrealized Gains	82	490
Unrealized (Losses)	(512)	(386)
Estimated Fair Value	395,804	412,674
U.S. Government Agency Securities
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	126,577	150,651
Unrealized Gains	41	148
Unrealized (Losses)	(146)	(204)
Estimated Fair Value	126,472	150,595
FDIC Certificates of Deposit
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	4,165	4,410
Unrealized Gains	0	2
Unrealized (Losses)	(6)	(12)
Estimated Fair Value	4,159	4,400
Certificates of Deposit
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	60,000	60,000
Unrealized Gains	0	0
Unrealized (Losses)	0	0
Estimated Fair Value	60,000	60,000
Commercial Paper
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	62,031	78,610
Unrealized Gains	4	59
Unrealized (Losses)	(35)	(27)
Estimated Fair Value	62,000	78,642
Corporate Notes/Bonds
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	143,461	118,899
Unrealized Gains	37	281
Unrealized (Losses)	(325)	(143)
Estimated Fair Value	$ 143,173	$ 119,037

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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