Securities - Amortized Cost and Fair Value of Debt Securities, by Contractual Maturity (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Available-for-Sale Securities, Debt Maturities [Abstract]
Amortized Cost, One year or less	$ 24,878
Amortized Cost, After one year through five years	244,319
Amortized Cost, After five years through ten years	31,945
Amortized Cost, Total	301,142
Amortized Cost, Mortgage-backed securities	94,061
Amortized Cost	395,203	$ 439,186
Fair Value, One year or less	24,274
Fair Value, After one year through five years	223,135
Fair Value, After five years through ten years	28,937
Fair Value, Total	276,346
Fair Value, Mortgage-backed securities	82,132
Total, Fair Value	$ 358,478	$ 390,789