Securities - Fair Values and Amortized Costs Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	$ 650,917	$ 685,170
Debt Securities, Available-for-Sale, Gross Unrealized Gains	13,914	3,514
Debt Securities, Available-for-Sale, Gross Unrealized Losses	(311)	(8,628)
Debt Securities, Available-for-Sale, Fair Value	664,520	680,056
Marketable equity securities	4,706	4,816
Total Securities	669,226	684,872
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	9,966	9,958
Debt Securities, Available-for-Sale, Gross Unrealized Gains	83	0
Debt Securities, Available-for-Sale, Gross Unrealized Losses	0	(222)
Debt Securities, Available-for-Sale, Fair Value	10,049	9,736
Obligations of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	128,257	129,267
Debt Securities, Available-for-Sale, Gross Unrealized Gains	1,908	68
Debt Securities, Available-for-Sale, Gross Unrealized Losses	0	(1,074)
Debt Securities, Available-for-Sale, Fair Value	130,165	128,261
Collateralized mortgage obligations of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	151,759	149,849
Debt Securities, Available-for-Sale, Gross Unrealized Gains	3,503	795
Debt Securities, Available-for-Sale, Gross Unrealized Losses	(252)	(1,985)
Debt Securities, Available-for-Sale, Fair Value	155,010	148,659
Residential mortgage-backed securities of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	18,504	24,564
Debt Securities, Available-for-Sale, Gross Unrealized Gains	345	203
Debt Securities, Available-for-Sale, Gross Unrealized Losses	(23)	(417)
Debt Securities, Available-for-Sale, Fair Value	18,826	24,350
Commercial mortgage-backed securities of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	234,076	251,660
Debt Securities, Available-for-Sale, Gross Unrealized Gains	3,911	0
Debt Securities, Available-for-Sale, Gross Unrealized Losses	(36)	(4,876)
Debt Securities, Available-for-Sale, Fair Value	237,951	246,784
Obligations of states and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	108,355	119,872
Debt Securities, Available-for-Sale, Gross Unrealized Gains	4,164	2,448
Debt Securities, Available-for-Sale, Gross Unrealized Losses	0	(54)
Debt Securities, Available-for-Sale, Fair Value	$ 112,519	$ 122,266

Debt Securities, Available-for-sale and Equity Securities, FV-NI

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Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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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).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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