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Note 4 - Fair Value Disclosure Measurements (Detail) - Assets Measured on a Recurring Basis (USD $) In Thousands, unless otherwise specified | Mar. 31, 2013 | Dec. 31, 2012
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Assets measured on a recurring basis: |  |
Assets Measured on a Recurring Basis | $ 190,687 | $ 194,472
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets measured on a recurring basis: |  |
Assets Measured on a Recurring Basis | 25,752 | 24,960
US Government Agencies Debt Securities [Member] |  |
Assets measured on a recurring basis: |  |
Assets Measured on a Recurring Basis | 25,752 | 24,960
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets measured on a recurring basis: |  |
Assets Measured on a Recurring Basis | 94,462 | 92,596
US States and Political Subdivisions Debt Securities [Member] |  |
Assets measured on a recurring basis: |  |
Assets Measured on a Recurring Basis | 94,462 | 92,596
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets measured on a recurring basis: |  |
Assets Measured on a Recurring Basis | 65,026 | 71,102
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] |  |
Assets measured on a recurring basis: |  |
Assets Measured on a Recurring Basis | 65,026 | 71,102
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets measured on a recurring basis: |  |
Assets Measured on a Recurring Basis | 4,697 | 5,064
Mortgage-backed Securities, Issued by Private Enterprises [Member] |  |
Assets measured on a recurring basis: |  |
Assets Measured on a Recurring Basis | 4,697 | 5,064
Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets measured on a recurring basis: |  |
Assets Measured on a Recurring Basis | 189,937 | 193,722
Debt Securities [Member] |  |
Assets measured on a recurring basis: |  |
Assets Measured on a Recurring Basis | 189,937 | 193,722
Equity Securities in Financial Institutions [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets measured on a recurring basis: |  |
Assets Measured on a Recurring Basis | 5 | 5
Equity Securities in Financial Institutions [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets measured on a recurring basis: |  |
Assets Measured on a Recurring Basis | 745 | 745
Equity Securities in Financial Institutions [Member] |  |
Assets measured on a recurring basis: |  |
Assets Measured on a Recurring Basis | 750 | 750
Fair Value, Inputs, Level 1 [Member] |  |
Assets measured on a recurring basis: |  |
Assets Measured on a Recurring Basis | 5 | 5
Fair Value, Inputs, Level 2 [Member] |  |
Assets measured on a recurring basis: |  |
Assets Measured on a Recurring Basis | $ 190,682 | $ 194,467

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- Definition Amount of investment in debt and equity securities categorized neither as trading securities nor held-to-maturity securities and intended be sold or mature one year or operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Section A -Paragraph 4, 5 -Chapter 3 -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 115 -Paragraph 12 -Subparagraph b -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 Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 16 -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 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-1/124-1 -Paragraph 15C -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 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=7534914&loc=d3e22054-111558 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 13, 17 -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 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-1/124-1 -Paragraph 15D -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 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 22 -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 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26626-111562 + Details
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