Investment Securities - Summary of Amortized Cost and Estimated Market Value of Investment Securities by Contractual Maturity (Detail) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Available-for-sale Securities, Debt Maturities [Abstract]
Amortized Cost, due in one year or less	$ 2,992
Amortized Cost, due after one year through five years	2,758
Amortized Cost, due after five years through ten years	11,639
Amortized Cost, due after ten years	43,644
Amortized Cost	61,033	$ 60,573
Fair Value, due in one year or less	2,964
Fair Value, due after one year through five years	2,660
Fair Value, due after five years through ten years	10,813
Fair Value, due after ten years	40,317
Fair Value	$ 56,754	$ 54,282