Investment Securities - Summary of Amortized Cost and Estimated Market Value of Investment Securities by Contractual Maturity (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Available-for-sale Securities, Debt Maturities [Abstract]
Amortized Cost, due in one year or less	$ 3,970
Amortized Cost, due after one year through five years	5,885
Amortized Cost, due after five years through ten years	8,484
Amortized Cost, due after ten years	41,200
Amortized Cost	59,539	$ 60,573
Fair Value, due in one year or less	3,886
Fair Value, due after one year through five years	5,662
Fair Value, due after five years through ten years	7,414
Fair Value, due after ten years	36,076
Fair Value	$ 53,038	$ 54,282