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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        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| Investment Securities     | NOTE 2. Investment SecuritiesTheamortized cost and approximate fair values of securities are asfollows:  Amortized Cost  Gross Unrealized Gains  Gross Unrealized Losses  Fair Value Availablefor sale at June 30, 2011            U.S.Government-sponsored agency securities $99  $14     $113 State andmunicipal  229,743   9,059  $289   238,513 Mortgage-backedsecurities  342,582   7,131   568   349,145 Corporateobligations  5,610       5,434   176 Equitysecurities  3,265           3,265 Totalavailable for sale  581,299   16,204   6,291   591,212 Held tomaturity at June 30, 2011                State andmunicipal  13,152   35   9   13,178 Mortgage-backedsecurities  334,002   5,799   1,114   338,687 Total heldto maturity  347,154   5,834   1,123   351,865 TotalInvestment Securities $928,453  $22,038  $7,414  $943,077   Amortized Cost  Gross Unrealized Gains  Gross Unrealized Losses  Fair Value Availablefor sale at December 31, 2010            U.S.Government-sponsored agency securities $600  $16     $616 State andmunicipal  233,622   7,108  $740   239,990 Mortgage-backedsecurities  293,311   4,293   2,287   295,317 Corporateobligations  5,856       5,674   182 Equitysecurities  3,265           3,265 Totalavailable for sale  536,654   11,417   8,701   539,370 Held tomaturity at December 31, 2010                State andmunicipal  10,070   389   5   10,454 Mortgage-backedsecurities  277,357   2,064   3,605   275,816 Total heldto maturity  287,427   2,453   3,610   286,270 TotalInvestment Securities $824,081  $13,870  $12,311  $825,640  Theamortized cost and fair value of available for sale securities andheld to maturity securities at June 30, 2011, by contractualmaturity, are shown below.  Expected maturities willdiffer from contractual maturities because issuers may have theright to call or prepay obligations with or without call orprepayment penalties.  Available for Sale  Held to Maturity   Amortized Cost  Fair Value  Amortized Cost  Fair Value MaturityDistribution at June 30, 2011:            Due in oneyear or less $4,379  $4,398  $3,234  $3,234 Due afterone through five years  13,602   13,917   1,447   1,450 Due afterfive through ten years  51,766   54,546   4,883   4,901 Due afterten years  165,705   165,941   3,588   3,593   $235,452  $238,802  $13,152  $13,178                  Mortgage-backedsecurities  342,582   349,145   334,002   338,687 Equitysecurities  3,265   3,265                          TotalInvestment Securities $581,299  $591,212  $347,154  $351,865 The carryingvalue of securities pledged as collateral, to secure publicdeposits and for other purposes, was $285,731,000 at June 30, 2011and $271,091,000 at December 31, 2010.The bookvalue of securities sold under agreements to repurchase amounted to$98,718,000 at June 30, 2011, and $84,965,000 at December 31,2010.For thethree and six months ended June 30, 2011 gross gains of $825,000and $1,288,000 were realized from sales and redemptions ofavailable for sale securities. For the three and six months endedJune 30, 2010 gross gains of $482,000 and $2,324,000 were realizedfrom sales and redemptions of available for salesecurities.  There were no gross losses resulting fromsales and redemptions of available for sale securities realized forthe three and six months ended June 30, 2011.  Grosslosses of $225,000 resulting from the sales and redemptions ofavailable for sale securities were recognized for both the threeand six months ended June 30, 2010.  The Corporation didnot recognize any other-than-temporary (“OTTI”) loss inthe three months ending June 30, 2011, but did recognize a $400,000OTTI loss in the three months ended June 30, 2010, equal to thecredit loss, establishing a new, lower amortized cost basis. TheCorporation has recognized OTTI losses of $400,000 and $888,000 inthe six months ended June 30, 2011 and 2010, equal to the creditloss, establishing a new, lower amortized cost basis.Certaininvestments in debt and equity securities are reported in thefinancial statements at an amount less than their historicalcost.  The historical cost of these investments totaled$184,106,000 and $273,853,000 at June 30, 2011, and December 31,2010, respectively.  Total fair value of theseinvestments at June 30, 2011, and December 31, 2010, was$176,691,000 and $261,542,000, which is approximately 18.8 percentand 31.6 percent of the Corporation’s available for sale andheld to maturity investment portfolio at June 30, 2011, andDecember 31, 2010.Except asdiscussed below, management believes the declines in fair value forthese securities are temporary.  Should the impairment ofany of these securities become other-than-temporary, the cost basisof the investment will be reduced and the resulting loss recognizedin net income in the period the OTTI is identified. Thefollowing table shows the Corporation’s investments’gross unrealized losses and fair value, aggregated by investmentcategory and length of time that individual securities have been ina continuous unrealized loss position at June 30, 2011, andDecember 31, 2010:  Less than 12 Months  12 Months or Longer  Total   Fair Value  Gross Unrealized Losses  Fair Value  Gross Unrealized Losses  Fair Value  Gross Unrealized Losses TemporarilyImpaired Investment                  Securitiesat June 30, 2011                  State andmunicipal $18,760  $(298)       $18,760  $(298)Mortgage-backedsecurities  157,787   (1,682)        157,787   (1,682)Corporateobligations         $144  $(5,434)  144   (5,434)TotalTemporarily Impaired Investment Securities $176,547  $(1,980) $144  $(5,434) $176,691  $(7,414)  Less than 12 Months  12 Months or Longer  Total   Fair Value  Gross Unrealized Losses  Fair Value  Gross Unrealized Losses  Fair Value  Gross Unrealized Losses TemporarilyImpaired Investment                  Securitiesat December 31, 2010                  State andmunicipal $31,796  $(745)       $31,796  $(745)Mortgage-backedsecurities  229,441   (5,892) $154      229,595   (5,892)Corporateobligations          151  $(5,674)  151   (5,674)TotalTemporarily Impaired Investment Securities $261,237  $(6,637) $305  $(5,674) $261,542  $(12,311)Mortgage-backedSecuritiesTheunrealized losses of $1.7 million on the Corporation’sinvestment in mortgage-backed securities were a result of changesin interest rates.  The Corporation expects to recoverthe amortized cost basis over the term of the securities as thedecline in market value is attributable to changes in interestrates and not credit quality. The Corporation does not intend tosell the investment and it is not more likely than not that theCorporation will be required to sell the investment before recoveryof its new, lower amortized cost basis, which may bematurity.  The Corporation does not consider theinvestment securities to be other-than-temporarily impaired at June30, 2011.State andMunicipalTheunrealized losses of $298,000 on the Corporation’s investmentin securities of state and political subdivisions were caused bychanges in interest rates.  The contractual terms ofthose investments do not permit the issuer to settle the securitiesat a price less than the amortized cost basis of theinvestments.  The Corporation does not intend to sell theinvestment and it is not more likely than not that the Corporationwill be required to sell the investment before recovery of its new,lower amortized cost basis, which may be maturity.  TheCorporation does not consider the investment securities to beother-than-temporarily impaired at June 30, 2011. CorporateObligationsTheCorporation’s unrealized losses on pooled trust preferredsecurities total $5.4 million on a book value of $5.6 million atJune 30, 2011. The decline in value is attributable to temporaryilliquidity and the financial crisis affecting these marketscoupled with the potential credit loss resulting from the adversechange in expected cash flows. Due to the illiquidity in themarket, it is unlikely that the Corporation would be able torecover its investment in these securities if the Corporation soldthe securities at this time. Management has analyzed the cash flowcharacteristics of the securities and this analysis includedutilizing the most recent trustee reports and any other relevantmarket information, including announcements of deferrals ordefaults of trust preferred securities. The Corporation did notrecognize any OTTI losses in the three months ending June 30, 2011.The Corporation has recognized an OTTI loss of $400,000 in the sixmonths ended June 30, 2011, equal to the credit loss, establishinga new, lower amortized cost basis. The credit loss was calculatedby comparing expected discounted cash flows based on performanceindicators of the underlying assets in the security to the carryingvalue of the investment.  The Corporation does not intendto sell the investment and it is not more likely than not that theCorporation will be required to sell the investment before recoveryof its new, lower amortized cost basis, which may bematurity.  The Corporation does not consider theremainder of the investment securities, which are classified asLevel 3 inputs in the fair value hierarchy, to beother-than-temporarily impaired at June 30, 2011.CreditLosses Recognized on InvestmentsCertain debtsecurities have experienced fair value deterioration due to creditlosses and other market factors. The following table providesinformation about debt securities for which only a credit loss wasrecognized in income and other losses are recorded in othercomprehensive income.  Accumulated Credit Losses in 2011  Accumulated Credit Losses in 2010 Creditlosses on debt securities held:      Balance,January 1 $10,955  $9,411 Additionsrelated to other-than-temporary losses not previouslyrecognized  400   888 Balance,June 30 $11,355  $10,299 |

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