Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) $ in Thousands	Dec. 31, 2019 USD ($) transfer	Dec. 31, 2018 USD ($) transfer
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Transfers between Level 1 and Level 2 \| transfer	1	1
ASSETS
Debt securities, available-for-sale	$ 779,133	$ 680,056
Marketable equity securities	5,150	4,816
U.S. Treasury securities
ASSETS
Debt securities, available-for-sale	10,040	9,736
Obligations of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	157,697	128,261
Collateralized mortgage obligations of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	189,348	148,659
Residential mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	22,418	24,350
Commercial mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	275,870	246,784
Obligations of states and political subdivisions
ASSETS
Debt securities, available-for-sale	116,133	122,266
Fair Value Measurements, Recurring
ASSETS
Debt securities, available-for-sale	779,133	680,056
Marketable equity securities	5,150	4,816
Total Securities	784,283	684,872
Securities held in a Rabbi Trust	5,987	4,725
Total Assets	816,239	695,407
LIABILITIES
Total Liabilities	25,615	5,340
Fair Value Measurements, Recurring \| U.S. Treasury securities
ASSETS
Debt securities, available-for-sale	10,040	9,736
Fair Value Measurements, Recurring \| Obligations of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	157,697	128,261
Fair Value Measurements, Recurring \| Collateralized mortgage obligations of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	189,348	148,659
Fair Value Measurements, Recurring \| Residential mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	22,418	24,350
Fair Value Measurements, Recurring \| Commercial mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	275,870	246,784
Fair Value Measurements, Recurring \| Corporate Bonds
ASSETS
Debt securities, available-for-sale	7,627
Fair Value Measurements, Recurring \| Obligations of states and political subdivisions
ASSETS
Debt securities, available-for-sale	116,133	122,266
Fair Value Measurements, Recurring \| Interest rate swaps
ASSETS
Derivative financial assets	25,647	5,504
LIABILITIES
Derivative financial liabilities	25,615	5,340
Fair Value Measurements, Recurring \| Interest rate lock commitments
ASSETS
Derivative financial assets	321	251
Fair Value Measurements, Recurring \| Forward sale contracts
ASSETS
Derivative financial assets	1	55
Fair Value Measurements, Recurring \| Level 1
ASSETS
Debt securities, available-for-sale	0	0
Marketable equity securities	5,078	0
Total Securities	5,078	0
Securities held in a Rabbi Trust	5,987	4,725
Total Assets	11,065	4,725
LIABILITIES
Total Liabilities	0	0
Fair Value Measurements, Recurring \| Level 1 \| U.S. Treasury securities
ASSETS
Debt securities, available-for-sale	0	0
Fair Value Measurements, Recurring \| Level 1 \| Obligations of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	0	0
Fair Value Measurements, Recurring \| Level 1 \| Collateralized mortgage obligations of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	0	0
Fair Value Measurements, Recurring \| Level 1 \| Residential mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	0	0
Fair Value Measurements, Recurring \| Level 1 \| Commercial mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	0	0
Fair Value Measurements, Recurring \| Level 1 \| Corporate Bonds
ASSETS
Debt securities, available-for-sale	0
Fair Value Measurements, Recurring \| Level 1 \| Obligations of states and political subdivisions
ASSETS
Debt securities, available-for-sale	0	0
Fair Value Measurements, Recurring \| Level 1 \| Interest rate swaps
ASSETS
Derivative financial assets	0	0
LIABILITIES
Derivative financial liabilities	0	0
Fair Value Measurements, Recurring \| Level 1 \| Interest rate lock commitments
ASSETS
Derivative financial assets	0	0
Fair Value Measurements, Recurring \| Level 1 \| Forward sale contracts
ASSETS
Derivative financial assets	0	0
Fair Value Measurements, Recurring \| Level 2
ASSETS
Debt securities, available-for-sale	779,133	680,056
Marketable equity securities	72	4,816
Total Securities	779,205	684,872
Securities held in a Rabbi Trust	0	0
Total Assets	805,174	690,682
LIABILITIES
Total Liabilities	25,615	5,340
Fair Value Measurements, Recurring \| Level 2 \| U.S. Treasury securities
ASSETS
Debt securities, available-for-sale	10,040	9,736
Fair Value Measurements, Recurring \| Level 2 \| Obligations of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	157,697	128,261
Fair Value Measurements, Recurring \| Level 2 \| Collateralized mortgage obligations of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	189,348	148,659
Fair Value Measurements, Recurring \| Level 2 \| Residential mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	22,418	24,350
Fair Value Measurements, Recurring \| Level 2 \| Commercial mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	275,870	246,784
Fair Value Measurements, Recurring \| Level 2 \| Corporate Bonds
ASSETS
Debt securities, available-for-sale	7,627
Fair Value Measurements, Recurring \| Level 2 \| Obligations of states and political subdivisions
ASSETS
Debt securities, available-for-sale	116,133	122,266
Fair Value Measurements, Recurring \| Level 2 \| Interest rate swaps
ASSETS
Derivative financial assets	25,647	5,504
LIABILITIES
Derivative financial liabilities	25,615	5,340
Fair Value Measurements, Recurring \| Level 2 \| Interest rate lock commitments
ASSETS
Derivative financial assets	321	251
Fair Value Measurements, Recurring \| Level 2 \| Forward sale contracts
ASSETS
Derivative financial assets	1	55
Fair Value Measurements, Recurring \| Level 3
ASSETS
Debt securities, available-for-sale	0	0
Marketable equity securities	0	0
Total Securities	0	0
Securities held in a Rabbi Trust	0	0
Total Assets	0	0
LIABILITIES
Total Liabilities	0	0
Fair Value Measurements, Recurring \| Level 3 \| U.S. Treasury securities
ASSETS
Debt securities, available-for-sale	0	0
Fair Value Measurements, Recurring \| Level 3 \| Obligations of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	0	0
Fair Value Measurements, Recurring \| Level 3 \| Collateralized mortgage obligations of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	0	0
Fair Value Measurements, Recurring \| Level 3 \| Residential mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	0	0
Fair Value Measurements, Recurring \| Level 3 \| Commercial mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities, available-for-sale	0	0
Fair Value Measurements, Recurring \| Level 3 \| Corporate Bonds
ASSETS
Debt securities, available-for-sale	0
Fair Value Measurements, Recurring \| Level 3 \| Obligations of states and political subdivisions
ASSETS
Debt securities, available-for-sale	0	0
Fair Value Measurements, Recurring \| Level 3 \| Interest rate swaps
ASSETS
Derivative financial assets	0	0
LIABILITIES
Derivative financial liabilities	0	0
Fair Value Measurements, Recurring \| Level 3 \| Interest rate lock commitments
ASSETS
Derivative financial assets	0	0
Fair Value Measurements, Recurring \| Level 3 \| Forward sale contracts
ASSETS
Derivative financial assets	$ 0	$ 0

Assets Held-in-Trust, Fair Value Disclosure

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Fair Value, Assets, Level 2 To Level 1 Transfers, Number Of Transfers

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Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]

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Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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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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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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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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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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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

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Fair value of financial and nonfinancial obligations.

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