Fair Value Measurements and Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Transfers between Levels [Abstract]
Transfers from Level 1 to Level 2	$ 0	$ 0	$ 0
Transfers from Level 2 to Level 1	0	0	4,000
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
AFS securities [Abstract]
AFS securities	932,173	932,173	998,496
Equity securities	26,818	26,818	23,053
Fair Value Measurements [Abstract]
Collateral dependent impaired loans with specific reserve	0	$ 0	200
Reserves on collateral dependent impaired loans			25
Minimum [Member]
Fair Value Measurements [Abstract]
Liquidation expense ratio on impaired collateral		10.00%
Maximum [Member]
Fair Value Measurements [Abstract]
Liquidation expense ratio on impaired collateral		35.00%
Changes Measurement [Member]
Fair Value Measurements [Abstract]
Branch location with pending disposition	(1,000)	$ (1,000)
Fair Value [Member]
Fair Value Measurements [Abstract]
Branch location with pending disposition	200	200
Recurring Basis [Member]
AFS securities [Abstract]
AFS securities	932,173	932,173	998,496
Equity securities	26,818	26,818	23,053
Derivatives	53,148	53,148	20,000
Total	1,012,139	1,012,139	1,041,549
Liabilities [Abstract]
Derivatives	53,102	53,102	17,572
Total	53,102	53,102	17,572
Recurring Basis [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	0	0	0
Equity securities	22,818	22,818	19,053
Derivatives	0	0	0
Total	22,818	22,818	19,053
Liabilities [Abstract]
Derivatives	0	0	0
Total	0	0	0
Recurring Basis [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	932,173	932,173	998,496
Equity securities	4,000	4,000	4,000
Derivatives	53,148	53,148	20,000
Total	989,321	989,321	1,022,496
Liabilities [Abstract]
Derivatives	53,102	53,102	17,572
Total	53,102	53,102	17,572
Recurring Basis [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities	0	0	0
Equity securities	0	0	0
Derivatives	0	0	0
Total	0	0	0
Liabilities [Abstract]
Derivatives	0	0	0
Total	0	0	0
Recurring Basis [Member] \| Federal Agency [Member]
AFS securities [Abstract]
AFS securities	29,831	29,831	84,299
Recurring Basis [Member] \| Federal Agency [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	0	0	0
Recurring Basis [Member] \| Federal Agency [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	29,831	29,831	84,299
Recurring Basis [Member] \| Federal Agency [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities	0	0	0
Recurring Basis [Member] \| State & Municipal [Member]
AFS securities [Abstract]
AFS securities	9	9	29,915
Recurring Basis [Member] \| State & Municipal [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	0	0	0
Recurring Basis [Member] \| State & Municipal [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	9	9	29,915
Recurring Basis [Member] \| State & Municipal [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities	0	0	0
Recurring Basis [Member] \| Mortgage-Backed [Member]
AFS securities [Abstract]
AFS securities	483,510	483,510	512,295
Recurring Basis [Member] \| Mortgage-Backed [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	0	0	0
Recurring Basis [Member] \| Mortgage-Backed [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	483,510	483,510	512,295
Recurring Basis [Member] \| Mortgage-Backed [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities	0	0	0
Recurring Basis [Member] \| Collateralized Mortgage Obligations [Member]
AFS securities [Abstract]
AFS securities	418,823	418,823	371,987
Recurring Basis [Member] \| Collateralized Mortgage Obligations [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	0	0	0
Recurring Basis [Member] \| Collateralized Mortgage Obligations [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	418,823	418,823	371,987
Recurring Basis [Member] \| Collateralized Mortgage Obligations [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities	$ 0	$ 0	$ 0

The percentage of liquidation expenses estimated with liquidating impaired collateral.

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Amount of loans considered to be collateral dependent.

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Amount of specific reserves for loans considered to be collateral dependent.

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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 and equity securities categorized neither as held-to-maturity nor trading.

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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 investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Amount of transfers of assets measured on a recurring basis out of Level 1 of the fair value hierarchy into Level 2.

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Amount of transfers of assets measured on a recurring basis out of Level 2 of the fair value hierarchy into Level 1.

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Amount of transfer of financial instrument classified as an asset into level 3 of the fair value hierarchy.

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Amount of transfers of financial instrument classified as an asset out of level 3 of the fair value hierarchy.

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Fair value of financial and nonfinancial obligations.

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Fair value portion of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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