Summary of Significant Accounting Policies - Components of Other Comprehensive Income (Loss) and Related Tax Effects (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax [Abstract]
Net unrealized gain (loss) on available-for-sale securities	$ 10,781	$ (44,366)	$ (10,948)
Reclassification adjustment for (gain) loss on sale of available-for-sale securities	891		(293)
Net unrealized gain (loss) on available-for-sale securities	11,672	(44,366)	(11,241)
Tax expense (benefit)	2,451	(9,317)	(2,360)
Other comprehensive income (loss)	$ 9,221	$ (35,049)	$ (8,881)

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Amount, before tax and after reclassification adjustment, of gain (loss) in value of unsold investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), attributable to parent.

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Amount, after reclassification adjustment, of tax expense (benefit) for gain (loss) in value of unsold investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), attributable to parent.

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Amount after tax of other comprehensive income (loss) attributable to parent entity.

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Amount before tax of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.

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Amount, before tax and adjustment, of unrealized holding gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Excludes unrealized gain (loss) on investment in debt security measured at amortized cost (held-to-maturity) from transfer to available-for-sale.

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