| **Income Taxes (Tables)**                             | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
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| **Income Tax Disclosure [Abstract]**                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| Current and Deferred Components of Income Tax Expense | The current and deferred components of income tax expense (benefit) were as follows:For the years ended December 31,2013 2012 2011Federal income tax     Current$3,234,000 $3,239,000 $2,828,000Deferred(56,000) (108,000) 730,000 3,178,000 3,131,000 3,558,000State franchise tax247,000 240,000 233,000 $3,425,000 $3,371,000 $3,791,000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| Actual Tax Expense from Expected Tax Expense          | The actual tax expense differs from the expected tax expense (computed by applying the applicable U.S. Federal corporate income tax rate to income before income taxes) as follows:For the years ended December 31,2013 2012 2011Expected tax expense$5,736,000 $5,621,000 $5,654,000Non-taxable income(2,326,000) (2,096,000) (1,794,000)State franchise tax, net of federal tax benefit160,000 156,000 152,000Tax credits(414,000) (414,000) (383,000)Other269,000 104,000 162,000 $3,425,000 $3,371,000 $3,791,000                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| Components of Deferred Tax Assets and Liabilities     | Items that give rise to the deferred income tax assets and liabilities and the tax effect of each at December 31, 2013 and 2012 are as follows: 2013 2012Allowance for loan losses$4,030,000 $4,375,000OREO116,000 131,000Accrued pension and post-retirement1,334,000 1,412,000Unrealized loss on securities available for sale3,549,000 —Goodwill206,000 —Tax credits, carried forward539,000 103,000Other assets163,000 89,000Total deferred tax asset9,937,000 6,110,000Net deferred loan costs(884,000) (770,000)Depreciation(2,672,000) (2,326,000)Unrealized gain on securities available for sale— (4,275,000)Mortgage servicing rights(405,000) (303,000)Core deposit intangible(99,000) (203,000)Investment in flow through entities(361,000) (323,000)Prepaid expense(316,000) (422,000)Total deferred tax liability(4,737,000) (8,622,000)Net deferred tax asset (liability)$5,200,000 $(2,512,000) |

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| - Definition
Tabular disclosure of the components of income tax expense attributable to continuing operations for each year presented including, but not limited to: current tax expense (benefit), deferred tax expense (benefit), investment tax credits, government grants, the benefits of operating loss carryforwards, tax expense that results from allocating certain tax benefits either directly to contributed capital or to reduce goodwill or other noncurrent intangible assets of an acquired entity, adjustments of a deferred tax liability or asset for enacted changes in tax laws or rates or a change in the tax status of the entity, and adjustments of the beginning-of-the-year balances of a valuation allowance because of a change in circumstances that causes a change in judgment about the realizability of the related deferred tax asset in future years.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319
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| - Definition
Tabular disclosure of the components of net deferred tax asset or liability recognized in an entity's statement of financial position, including the following: the total of all deferred tax liabilities, the total of all deferred tax assets, the total valuation allowance recognized for deferred tax assets.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319
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| - Definition
Tabular disclosure of the reconciliation using percentage or dollar amounts of the reported amount of income tax expense attributable to continuing operations for the year to the amount of income tax expense that would result from applying domestic federal statutory tax rates to pretax income from continuing operations.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32687-109319
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