| **Derivative Financial Instruments**                                    | 3 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
|-------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
||
| **Derivative Instruments and Hedging Activities Disclosure [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| Derivative Financial Instruments                                        | DERIVATIVE FINANCIAL INSTRUMENTS Risk Management Objective of Using DerivativesThe Corporation is exposed to certain risks arising from both its business operations and economic conditions.  The Corporation principally manages its exposures to a wide variety of business and operational risks through management of its core business activities.  The Corporation manages economic risks, including interest rate, liquidity, and credit risk, primarily by managing the amount, sources, and duration of its assets and liabilities and through the use of derivative financial instruments.  Specifically, the Corporation enters into derivative financial instruments to manage exposures that arise from business activities that result in the receipt or payment of future known and uncertain cash amounts, the value of which are determined by interest rates.  The Corporation’s derivative financial instruments are used to manage differences in the amount, timing, and duration of the Corporation’s known or expected cash payments principally related to certain variable-rate liabilities.  The Corporation also has derivatives that are a result of a service the Corporation provides to certain qualifying customers, and, therefore, are not used to manage interest rate risk in the Corporation’s assets or liabilities.  The Corporation manages a matched book with respect to its derivative instruments offered as a part of this service to its customers in order to minimize its net risk exposure resulting from such transactions.Cash Flow Hedges of Interest Rate RiskThe Corporation’s objectives in using interest rate derivatives are to add stability to interest expense and to manage its exposure to interest rate movements.  To accomplish these objectives, the Corporation primarily uses interest rate swaps and interest rate caps as part of its interest rate risk management strategy.  Interest rate swaps designated as cash flow hedges involve the payment of fixed amounts to a counterparty in exchange for the Corporation receiving variable payments over the life of the agreements without exchange of the underlying notional amount.  Interest rate caps designated as cash flow hedges involve the receipt of variable amounts from a counterparty if interest rates rise above the strike rate on the contract in exchange for an up-front premium.  As of March 31, 2015 and 2014, the Corporation had five interest rate swaps with a notional amount of $56.0 million and one interest rate cap with a notional amount of $13.0 million that were designated as cash flow hedges.  The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive income and is subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. During 2015, $26.0 million of the interest rate swaps and the $13.0 million interest rate cap were used to hedge the variable cash outflows (LIBOR-based) associated with existing trust preferred securities when the outflows converted from a fixed rate to variable rate in September of 2012.  In addition, the remaining $30.0 million of interest rate swaps were used to hedge the variable cash outflows (LIBOR-based) associated with three Federal Home Loan Bank advances.  The ineffective portion of the change in fair value of the derivatives is recognized directly in earnings.  During the three months ended March 31, 2015, and 2014, the Corporation did not recognize any ineffectiveness.Amounts reported in accumulated other comprehensive income related to derivatives will be reclassified to interest expense as interest payments are made on the Corporation’s variable-rate liabilities.  During the next twelve months, the Corporation expects to reclassify $1,346,000 from accumulated other comprehensive income to interest expense.Non-designated HedgesThe Corporation does not use derivatives for trading or speculative purposes.  Derivatives not designated as hedges are not speculative and result from a service the Corporation provides to certain customers.  The Corporation executes interest rate swaps with commercial banking customers to facilitate their respective risk management strategies.  Those interest rate swaps are simultaneously hedged by offsetting interest rate swaps that the Corporation executes with a third party, such that the Corporation minimizes its net risk exposure resulting from such transactions.  As the interest rate swaps associated with this program do not meet the strict hedge accounting requirements, changes in the fair value of both the customer swaps and the offsetting swaps are recognized directly in earnings.  As of March 31, 2015, the notional amount of customer-facing swaps was approximately $137,186,000.  This amount is offset with third party counterparties, as described above.Fair Values of Derivative Instruments on the Balance SheetThe table below presents the fair value of the Corporation’s derivative financial instruments, as well as their classification on the Balance Sheet, as of March 31, 2015, and December 31, 2014.  Asset DerivativesLiability Derivatives March 31, 2015December 31, 2014March 31, 2015December 31, 2014 BalanceSheetLocationFairValueBalanceSheetLocationFairValueBalanceSheetLocationFairValueBalanceSheetLocationFairValueDerivatives designated as hedging instruments:        Interest rate contractsOther Assets$87Other Assets$137Other Liabilities$3,547Other Liabilities$2,650Derivatives not designated as hedging instruments:        Interest rate contractsOther Assets$4,764Other Assets$3,730Other Liabilities$5,022Other Liabilities$3,887  Effect of Derivative Instruments on the Income StatementThe tables below present the effect of the Corporation’s derivative financial instruments on the Income Statement for three months ended March 31, 2015, and 2014. Derivatives Not Designated asHedging Instruments underFASB ASC 815-10Location of Gain (Loss)Recognized Income onDerivativeAmount of Gain (Loss)Recognized Income onDerivativeAmount of Gain (Loss)Recognized Income onDerivative  Three Months EndedMarch 31, 2015Three Months Ended March 31, 2014Interest rate contractsOther income$(100)$19       The amount of gain (loss) recognized in other comprehensive income is included in the table below for the periods indicated.Derivatives in Cash Flow Hedging RelationshipsAmount of Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)Three Months EndedMarch 31, 2015 March 31, 2014Interest Rate Products$(1,276) $(1,266)The amount of gain (loss) reclassified from other comprehensive income into income is included in the table below for the periods indicated.Location of Loss Reclassified from Accumulated Other Comprehensive Income (Effective Portion)Amount of Gain (Loss) Reclassified from Other Comprehensive Income into Income (Effective Portion)Three Months EndedMarch 31, 2015 March 31, 2014Interest Expense$(354) $(344)The Corporation’s exposure to credit risk occurs because of nonperformance by its counterparties.  The counterparties approved by the Corporation are usually financial institutions, which are well capitalized and have credit ratings through Moody’s and/or Standard & Poor’s, at or above investment grade.  The Corporation’s control of such risk is through quarterly financial reviews, comparing mark-to-mark values with policy limitations, credit ratings and collateral pledging.Credit-risk-related Contingent FeaturesThe Corporation has agreements with certain of its derivative counterparties that contain a provision where if the Corporation fails to maintain its status as a well or adequate capitalized institution, then the Corporation could be required to terminate or fully collateralize all outstanding derivative contracts.The Corporation also has agreements with certain of its derivative counterparties that contain a provision where if the Corporation defaults on any of its indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender, the Corporation could also be declared in default on its derivative obligations.  As of March 31, 2015, the termination value of derivatives in a net liability position related to these agreements was $8,823,000.  As of March 31, 2015, the Corporation had minimum collateral posting thresholds with certain of its derivative counterparties and had posted collateral of $10,031,000.  If the Corporation had breached any of these provisions at March 31, 2015, it could have been required to settle its obligations under the agreements at their termination value. |

| X                                                                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The entire disclosure for derivative instruments and hedging activities including, but not limited to, risk management strategies, non-hedging derivative instruments, assets, liabilities, revenue and expenses, and methodologies and assumptions used in determining the amounts.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80748-113994Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5618551-113959Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4K -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5708775-113959Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 25 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4E -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624181-113959Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6441202&loc=d3e80720-113993Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4H -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624258-113959Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624163-113959Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(n)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690Reference 10: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4J -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5708773-113959Reference 11: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80784-113994Reference 12: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4D -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624177-113959Reference 13: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=35706170&loc=d3e41620-113959Reference 14: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5579245-113959Reference 15: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5580258-113959Reference 16: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5579240-113959Reference 17: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=35706170&loc=d3e41641-113959Reference 18: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=35706170&loc=d3e41638-113959Reference 19: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959
+ Details**Name:**us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock**Namespace Prefix:**us-gaap_**Data Type:**nonnum:textBlockItemType**Balance Type:**na**Period Type:**duration |