Fair Value Measurements and Fair Value of Financial Instruments, Fair Value of Financial Assets and Liabilities Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2022	Dec. 31, 2021
AFS securities [Abstract]
AFS securities	$ 1,662,697	$ 1,687,361
Equity securities	32,554	33,550
Fair Value Measurements [Abstract]
Collateral dependent impaired loans with specific reserve	9,900	10,200
Reserves on collateral dependent impaired loans	$ 0	0
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%
U.S. Treasury [Member]
AFS securities [Abstract]
AFS securities	$ 117,635	73,069
Federal Agency [Member]
AFS securities [Abstract]
AFS securities	225,612	239,931
State & Municipal [Member]
AFS securities [Abstract]
AFS securities	88,302	94,088
Corporate [Member]
AFS securities [Abstract]
AFS securities	54,752	52,003
Recurring Basis [Member]
AFS securities [Abstract]
AFS securities	1,662,697	1,687,361
Equity securities	32,554	33,550
Derivatives	49,486	60,625
Total	1,744,737	1,781,536
Liabilities [Abstract]
Derivatives	49,088	60,263
Total	49,088	60,263
Recurring Basis [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	117,635	73,069
Equity securities	31,554	32,550
Derivatives	0	0
Total	149,189	105,619
Liabilities [Abstract]
Derivatives	0	0
Total	0	0
Recurring Basis [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	1,545,062	1,614,292
Equity securities	1,000	1,000
Derivatives	49,486	60,625
Total	1,595,548	1,675,917
Liabilities [Abstract]
Derivatives	49,088	60,263
Total	49,088	60,263
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] \| U.S. Treasury [Member]
AFS securities [Abstract]
AFS securities	117,635	73,069
Recurring Basis [Member] \| U.S. Treasury [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	117,635	73,069
Recurring Basis [Member] \| U.S. Treasury [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| U.S. Treasury [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| Federal Agency [Member]
AFS securities [Abstract]
AFS securities	225,612	239,931
Recurring Basis [Member] \| Federal Agency [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| Federal Agency [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	225,612	239,931
Recurring Basis [Member] \| Federal Agency [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| State & Municipal [Member]
AFS securities [Abstract]
AFS securities	88,302	94,088
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	88,302	94,088
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	558,397	606,675
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	558,397	606,675
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	617,999	621,595
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	617,999	621,595
Recurring Basis [Member] \| Collateralized Mortgage Obligations [Member] \| Level 3 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| Corporate [Member]
AFS securities [Abstract]
AFS securities	54,752	52,003
Recurring Basis [Member] \| Corporate [Member] \| Level 1 [Member]
AFS securities [Abstract]
AFS securities	0	0
Recurring Basis [Member] \| Corporate [Member] \| Level 2 [Member]
AFS securities [Abstract]
AFS securities	54,752	52,003
Recurring Basis [Member] \| Corporate [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 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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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as current.

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Fair value of financial and nonfinancial obligations.

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