Derivative Financial Instruments and Hedging Activities - Information on Derivatives (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Carrying Amounts of Hedged Assets	$ 18,378		$ 18,378		$ 17,917
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Loans	941		941		6
Interest and fees on loans	20,988	$ 19,624	41,683	$ 38,511
Fair value hedge \| Interest income
Derivatives, Fair Value [Line Items]
(Decrease) increase in value of designated interest rate swaps due to LIBOR interest rate movements	(547)	187	(904)	716
Payment on interest rate swaps	(14)	(40)	(26)	(95)
Increase (decrease) in value of hedged loans	573	(116)	935	(693)
Decrease in value of yield maintenance agreement	(3)	(3)	(7)	(7)
Net loss on derivatives recognized against interest income	9	$ 28	(2)	$ (79)
Fair value hedge \| Designated as hedging instrument \| Interest rate swap \| Other assets
Derivatives, Fair Value [Line Items]
Interest rate contracts notional amount, asset derivatives	0		0		8,895
Interest rate contracts fair value, asset derivatives	0		0		161
Fair value hedge \| Designated as hedging instrument \| Interest rate swap \| Other liabilities
Derivatives, Fair Value [Line Items]
Interest rate contracts notional amount, liability derivatives	17,437		17,437		9,016
Interest rate contracts fair value, liability derivatives	$ 1,118		$ 1,118		$ 375

Increase (Decrease) in value of yield maintenance agreement recognized against interest income.

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Payment on interest rate swaps recorded in interest income.

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Nominal or face amount used to calculate payments on the derivative asset.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Nominal or face amount used to calculate payments on the derivative liability.

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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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Amount of asset hedged in fair value hedging relationship.

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Amount of cumulative increase (decrease) in fair value of hedged asset in fair value hedge, attributable to hedged risk.

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Amount of unrealized gain (loss) included in earnings related to the fair value of the hedged item in an interest rate fair value hedge, offset by the gain (loss) on the hedging instrument to the extent that the fair value hedge is determined to be effective.

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Amount of unrealized gain (loss) related to the fair value of interest rate derivatives designated as fair value hedging instruments, as offset by the gain (loss) on the hedged item to the extent that the fair value hedge is determined to be effective.

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The aggregate interest and fee income generated by: (1) loans the Entity has positive intent and ability to hold for the foreseeable future, or until maturity or payoff, including commercial and consumer loans, whether domestic or foreign, which may consist of: (a) industrial and agricultural; (b) real estate; and (c) real estate construction loans; (d) trade financing; (e) lease financing; (f) home equity lines-of-credit; (g) automobile and other vehicle loans; and (h) credit card and other revolving-type loans and (2) loans and leases held-for-sale which may include mortgage loans, direct financing, and sales-type leases.

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