| **Quarterly Information (Tables)**   | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     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| **Quarterly Information [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              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| Quarterly information                | The following tables provide unaudited financial information by quarter for each of the past two years:Dollars in thousands except per share data  2011Q1   2011Q2   2011Q3   2011Q4   2012Q1   2012Q2   2012Q3   2012Q4 Balance Sheets                                Cash $13,700  $14,322  $16,563  $14,115  $12,123  $14,192  $14,904  $14,958 Interest-bearing deposits in other banks  100   100   100   -   1,532   -   681   1,638 Investments  435,387   427,248   456,481   408,863   454,717   443,122   454,156   434,934 Restricted equity securities  15,443   15,443   15,443   15,443   14,823   14,448   14,448   14,448 Net loans for sale and loans held  881,134   872,314   853,484   851,988   858,122   867,808   855,132   857,819 Other assets  85,274   88,263   84,967   82,458   82,475   85,187   83,995   91,202    Total assets $1,431,038  $1,417,690  $1,427,038  $1,372,867  $1,423,792  $1,424,757  $1,423,316  $1,414,999 Deposits $1,050,257  $998,838  $1,004,894  $941,333  $1,015,835  $1,005,274  $944,547  $958,850 Borrowed funds  217,534   249,336   255,616   265,663   240,151   248,926   304,749   282,905 Other liabilities  11,703   13,306   15,990   15,013   16,213   17,152   17,383   16,921 Shareholders' equity  151,544   156,210   150,538   150,858   151,593   153,405   156,637   156,323   Total liabilities   & equity $1,431,038  $1,417,690  $1,427,038  $1,372,867  $1,423,792  $1,424,757  $1,423,316  $1,414,999 Income and Comprehensive Income Statements Interest income $14,254  $13,997  $13,898  $13,553  $13,106  $13,133  $12,892  $12,694 Interest expense  3,749   3,774   3,670   3,516   3,300   3,215   3,222   3,201    Net interest income  10,505   10,223   10,228   10,037   9,806   9,918   9,670   9,493    Provision for   loan losses  2,100   2,000   1,500   4,950   2,100   2,800   1,400   1,535 Net interest income after provision for loan losses  8,405   8,223   8,728   5,087   7,706   7,118   8,270   7,958 Non-interest income  2,277   2,234   2,080   5,159   2,168   3,896   2,492   2,722 Non-interest expense  6,488   6,250   6,934   6,366   6,178   6,730   6,595   6,768    Income before taxes  4,194   4,207   3,874   3,880   3,696   4,284   4,167   3,912 Income taxes  1,051   1,014   868   858   783   961   944   683    Net income $3,143  $3,193  $3,006  $3,022  $2,913  $3,323  $3,223  $3,229 Basic earnings per share $0.29  $0.29  $0.27  $0.29  $0.28  $0.32  $0.31  $0.31 Diluted earnings per share $0.29  $0.29  $0.27  $0.29  $0.28  $0.32  $0.31  $0.31 Other comprehensive income (loss), net of tax Net unrealized gain (loss) on securities available for sale $668  $3,587  $5,957  $(754) $(313) $438  $1,962  $(1,548)Unrecognized gain (loss) on postretirement benefits  5   5   4   (28)  5   5   5   (51)Other  comprehensive income (loss) $673  $3,592  $5,961  $(782) $(308) $443  $1,967  $(1,599)Comprehensive income $3,816  $6,785  $8,967  $2,240  $2,605  $3,766  $5,190  $1,630  |

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| - Definition
Tabular disclosure of the quarterly financial data in the annual financial statements. The disclosure includes financial information for each fiscal quarter for the current and previous year, including revenues, gross profit, income (loss) before extraordinary items and cumulative effect of a change in accounting principle and earnings per share data.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Topic 270 -SubTopic 10 -Publisher FASB -Number  -Article  -Subparagraph (a)-(j) -Name Accounting Standards Codification -Paragraph 1 -Section 50 -URI http://asc.fasb.org/extlink&oid=6952194&loc=d3e1280-108306
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