Securities - Fair Values and Amortized Costs Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	$ 673,638	$ 685,170
Debt Securities, Available-for-Sale, Gross Unrealized Gains	5,962	3,514
Debt Securities, Available-for-Sale, Gross Unrealized Losses	(3,678)	(8,628)
Debt Securities, Available-for-Sale, Fair Value	675,922	680,056
Marketable equity securities	4,498	4,816
Total Securities	680,420	684,872
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	9,961	9,958
Debt Securities, Available-for-Sale, Gross Unrealized Gains	0	0
Debt Securities, Available-for-Sale, Gross Unrealized Losses	(124)	(222)
Debt Securities, Available-for-Sale, Fair Value	9,837	9,736
Obligations of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	129,263	129,267
Debt Securities, Available-for-Sale, Gross Unrealized Gains	373	68
Debt Securities, Available-for-Sale, Gross Unrealized Losses	(267)	(1,074)
Debt Securities, Available-for-Sale, Fair Value	129,369	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	153,717	149,849
Debt Securities, Available-for-Sale, Gross Unrealized Gains	1,608	795
Debt Securities, Available-for-Sale, Gross Unrealized Losses	(1,166)	(1,985)
Debt Securities, Available-for-Sale, Fair Value	154,159	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	22,481	24,564
Debt Securities, Available-for-Sale, Gross Unrealized Gains	229	203
Debt Securities, Available-for-Sale, Gross Unrealized Losses	(196)	(417)
Debt Securities, Available-for-Sale, Fair Value	22,514	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	239,196	251,660
Debt Securities, Available-for-Sale, Gross Unrealized Gains	272	0
Debt Securities, Available-for-Sale, Gross Unrealized Losses	(1,914)	(4,876)
Debt Securities, Available-for-Sale, Fair Value	237,554	246,784
Obligations of states and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	119,020	119,872
Debt Securities, Available-for-Sale, Gross Unrealized Gains	3,480	2,448
Debt Securities, Available-for-Sale, Gross Unrealized Losses	(11)	(54)
Debt Securities, Available-for-Sale, Fair Value	$ 122,489	$ 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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Amount 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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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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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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