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Fair Value of Instruments (Details Textual) (USD $) In Thousands, unless otherwise specified | 3 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Mar. 31, 2013 | Dec. 31, 2012 | Mar. 31, 2012
Fair Value of Financial Instruments (Textual) [Abstract] |  |  |
Impaired Loans Categorized as Level 3 | $ 4,144 | $ 4,591 | $ 1,867
Specific Allocation for Impaired Loans | 860 |  | 191
Fair Value of Financial Instruments (Additional Textual) [Abstract] |  |  |
Interest-Bearing Deposits Maturing | 90 days |  |
Carrying Amounts of Dividends Payable, Number of days | 40 days |  |
Impairment of Mortgage servicing rights |  | 16 |
No impairment charge to other expense was required to adjust these assets to their estimated fair values | 0 | 0 |
Fair Value on a Recurring Basis [Member] |  |  |
Fair Value of Financial Instruments (Textual) [Abstract] |  |  |
Specific Allocation for Impaired Loans | 860 | 865 |
Significant Unobservable Inputs (Level 3) [Member] |  |  |
Fair Value of Financial Instruments (Textual) [Abstract] |  |  |
Impaired Loans Categorized as Level 3 | $ 4,100 | $ 4,600 |

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- Definition The charge against earnings resulting from the aggregate write down of all assets from their carrying value to their fair value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 144 -Paragraph 45, 46, 47 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2420-110228 + Details
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