Investment Securities - Schedule of Scheduled Maturities of Securities Available-for-Sale and Held-to-Maturity (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Available-for-Sale, Amortized Cost
Due in one year or less	$ 75,002
Due from after five to ten years	4,011
Due after ten years	38,571
Amortized Cost	117,584	$ 92,181
Available-for-Sale, Fair Value
Due in one year or less	75,002
Due from after five to ten years	4,091
Due after ten years	39,751
Total	118,844	92,791
Held-to-Maturity, Amortized Cost
Due from one to five years	2,014
Due from after five to ten years	9,416
Due after ten years	11,684
Amortized Cost	23,114	23,914
Held-to-Maturity, Fair Value
Due from one to five years	2,061
Due from after five to ten years	9,868
Due after ten years	12,206
Total	$ 24,135	$ 24,678