Investment Securities - Summary of Contractual Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Available-for-sale Securities, Debt Maturities [Abstract]
Amortized Cost, Due in 1 year or less	$ 0	$ 111
Fair Value (Estimated), Due in 1 year or less	0	112
Amortized Cost, Due in 1 to 5 years	13,501	841
Fair Value (Estimated), Due in 1 to 5 years	13,518	842
Amortized Cost, Due in 5 to 10 years	83,954	29,003
Fair Value (Estimated), Due in 1 to 5 years	83,326	29,177
Amortized Cost, Due after 10 years	226,354	270,594
Fair Value (Estimated), Due after 10 years	220,572	266,627
Securities available-for-sale, Amortized Cost	323,809
Fair Value (Estimated)	317,416
Equity securities, Amortized Cost		323
Equity securities, Fair Value (Estimated)		441
Amortized Cost		300,872
Fair Value (Estimated)		297,199
Debt Securities, Held-to-maturity, Maturity [Abstract]
Amortized Cost, Due in 1 year or less	1,432	635
Fair Value (Estimated), Due in 1 year or less	1,433	637
Amortized Cost, Due in 1 to 5 years	20,717	18,059
Fair Value (Estimated), Due in 1 to 5 years	20,778	18,164
Amortized Cost, Due in 5 to 10 years	157,544	37,182
Fair Value (Estimated), Due in 1 to 5 years	155,313	37,719
Amortized Cost, Due after 10 years	75,970	200,691
Fair Value (Estimated), Due after 10 years	73,376	203,135
Amortized Cost	255,663	256,567
Fair Value (Estimated)	$ 250,900	$ 259,655

Debt Securities, Available-for-sale, Amortized Cost and Equity Securities

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth fiscal year through tenth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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