Securities - Summary of Amortized Cost and Fair Value of Debt Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Available-for-sale
Due in one year or less, Amortized Cost	$ 15,006
Due after one through five years, Amortized Cost	55,512
Due after five through ten years, Amortized Cost	24,135
Due after ten years, Amortized Cost	67,035
Amortized Cost, Available-for-sale	161,688	$ 164,705
Due in one year or less, Fair Value	14,780
Due after one through five years, Fair Value	51,631
Due after five through ten years, Fair Value	21,304
Due after ten years, Fair Value	57,615
Total debt securities available-for-sale, Fair Value	145,330	150,069
Held-to-maturity
Due after one through five years, Amortized cost	7,434
Due after five through ten years, Amortized Cost	5,138
Due after ten years, Amortized Cost	217,933
Amortized Cost, Held to maturity	230,505	247,401
Due after one through five years, Fair Value	6,876
Due after five through ten years, Fair Value	4,295
Due after ten years, Fair Value	176,524
Total debt securities held-to-maturity, Fair Value	$ 187,695	$ 211,954