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Note 4 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans (Details) - Summary of Loans Past Due 90 Days or More and Impaired Loans (USD $) In Thousands, unless otherwise specified | 9 Months Ended | 12 Months Ended
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Sep. 30, 2014 | Sep. 30, 2013 | Dec. 31, 2013
Summary of Loans Past Due 90 Days or More and Impaired Loans [Abstract] |  |  |  |  |  |
Loans past due 90 days or more and still accruing | $ 485 | [1] | $ 149 |  | $ 190 | [1]
Ratio of loans past due 90 days or more and still accruing to loans, net of unearned income and deferred fees | 0.08% |  | 0.03% |  | 0.03% |
Accruing restructured loans | 5,947 |  | 6,545 |  | 6,191 |
Impaired loans: |  |  |  |  |  |
Impaired loans with no valuation allowance | 9,223 | [2] |  |  | 10,635 | [3]
Impaired loans with no valuation allowance |  |  | 14,874 |  | 10,372 |
Impaired loans with a valuation allowance | 5,964 | [2] |  |  | 2,354 | [3]
Impaired loans with a valuation allowance |  |  | 2,172 |  | 2,613 |
Total impaired loans | 15,187 |  | 17,046 |  | 12,985 |
Valuation allowance | (296) |  | (631) |  | (624) |
Impaired loans, net of allowance | 14,891 |  | 16,415 |  | 12,361 |
Average recorded investment in impaired loans(1) | 15,974 | [2],[4] | 17,357 | [2] | 16,654 | [2],[3],[4]
Interest income recognized on impaired loans, after designation as impaired | $ 384 | [4] | $ 159 |  | $ 267 | [4]
[1] | Only classes with past-due or nonaccrual loans are shown.
[2] | Recorded investment is net of charge-offs and interest paid while a loan is in nonaccrual status.
[3] | Recorded investment includes principal net of unearned interest and deferred fees and costs, and accrued interest.
[4] | Only classes with impaired loans are shown.

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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=35738203&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=35738203&loc=d3e5258-111524 + Details
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