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Note 4 - Loans And Related Allowance For Loan Losses (Detail) - Additional Information on Impaired Loans (USD $) In Thousands, unless otherwise specified | 12 Months Ended
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Dec. 31, 2012 | Dec. 31, 2011 | Dec. 31, 2010
Commercial and Industrial [Member] |  |  |
Total: |  |  |
Impaired loans, average recorded investment | $ 2,776 | $ 1,637 | $ 3,149
Impaired loans, interest income recognized | 348 | 58 | 13
Real Estate Construction [Member] |  |  |
Total: |  |  |
Impaired loans, average recorded investment | 2,798 | 4,521 | 618
Impaired loans, interest income recognized | 156 | 216 | 1
Residential Real Estate Mortgage [Member] |  |  |
Total: |  |  |
Impaired loans, average recorded investment | 4,263 | 3,188 | 594
Impaired loans, interest income recognized | 338 | 157 |
Commercial Real Estate Mortgage [Member] |  |  |
Total: |  |  |
Impaired loans, average recorded investment | 4,717 | 5,083 | 3,320
Impaired loans, interest income recognized | 543 | 97 | 69
Consumer Installment [Member] |  |  |
Total: |  |  |
Impaired loans, average recorded investment | 27 | 24 |
Impaired loans, interest income recognized | $ 3 | $ 2 |

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- Definition Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5212-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5258-111524 + Details
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- Definition Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5212-111524 + Details
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