Fair Value Measurements and Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Dec. 31, 2019
AFS securities [Abstract]
AFS securities	$ 1,000,980	$ 975,340
Equity securities	26,378	27,771
Fair Value Measurements [Abstract]
Collateral dependent impaired loans with specific reserve	4,200	0
Reserves on collateral dependent impaired loans	$ 2,100
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	50.00%
Recurring Basis [Member]
AFS securities [Abstract]
AFS securities	$ 1,000,980	975,340
Equity securities	26,378	27,771
Derivatives	118,963	41,766
Total	1,146,321	1,044,877
Liabilities [Abstract]
Derivatives	119,044	41,777
Total	119,044	41,777
Recurring Basis [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	0	0
Equity securities	22,378	23,771
Derivatives	0	0
Total	22,378	23,771
Liabilities [Abstract]
Derivatives	0	0
Total	0	0
Recurring Basis [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	1,000,980	975,340
Equity securities	4,000	4,000
Derivatives	118,963	41,766
Total	1,123,943	1,021,106
Liabilities [Abstract]
Derivatives	119,044	41,777
Total	119,044	41,777
Recurring Basis [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities	0	0
Equity securities	0	0
Derivatives	0	0
Total	0	0
Liabilities [Abstract]
Derivatives	0	0
Total	0	0
Recurring Basis [Member] \| Federal Agency [Member]
AFS securities [Abstract]
AFS securities		34,758
Recurring Basis [Member] \| Federal Agency [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities		0
Recurring Basis [Member] \| Federal Agency [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities		34,758
Recurring Basis [Member] \| Federal Agency [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities		0
Recurring Basis [Member] \| State & Municipal [Member]
AFS securities [Abstract]
AFS securities	2,619	2,513
Recurring Basis [Member] \| State & Municipal [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| State & Municipal [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	2,619	2,513
Recurring Basis [Member] \| State & Municipal [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| Mortgage-Backed [Member]
AFS securities [Abstract]
AFS securities	532,123	503,626
Recurring Basis [Member] \| Mortgage-Backed [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| Mortgage-Backed [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	532,123	503,626
Recurring Basis [Member] \| Mortgage-Backed [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| Collateralized Mortgage Obligations [Member]
AFS securities [Abstract]
AFS securities	466,238	434,443
Recurring Basis [Member] \| Collateralized Mortgage Obligations [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| Collateralized Mortgage Obligations [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	466,238	434,443
Recurring Basis [Member] \| Collateralized Mortgage Obligations [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities	$ 0	$ 0

The percentage of liquidation expenses estimated with liquidating impaired collateral.

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Amount of loans considered to be collateral dependent.

+ References

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

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- Definition

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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Fair value of financial and nonfinancial obligations.

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