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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 | 3 Months Ended | 6 Months Ended | 12 Months Ended
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Jun. 30, 2013 | Jun. 30, 2013 | Jun. 30, 2012 | Dec. 31, 2012
Summary of Loans Past Due 90 Days or More and Impaired Loans [Abstract] |  |  |  |  |  |  |  |
Loans past due 90 days or more and still accruing | $ 125 |  | $ 125 |  | $ 242 |  | $ 170 |
Ratio of loans past due 90 days or more and still accruing to loans, net of unearned income and deferred fees | 0.02% |  | 0.02% |  | 0.04% |  | 0.03% |
Accruing restructured loans | 6,234 |  | 6,234 |  | 2,035 |  | 2,005 |
Impaired loans with no valuation allowance | 15,946 |  | 15,946 |  | 12,374 |  | 16,974 |
Impaired loans with a valuation allowance | 1,449 |  | 1,449 |  | 1,543 |  | 1,482 |
Total impaired loans | 17,395 |  | 17,395 |  | 13,917 |  | 18,456 |
Valuation allowance | (273) |  | (273) |  | (362) |  | (554) |
Impaired loans, net of allowance | 17,122 |  | 17,122 |  | 13,555 |  | 17,902 |
Average recorded investment in impaired loans(1) | 17,567 | [1] | 17,889 | [1],[2] | 14,055 | [2] | 13,540 | [2],[3]
Interest income recognized on impaired loans, after designation as impaired | 39 |  | 77 |  | 186 |  | 9 |
Amount of income recognized on a cash basis |  |  | $ 0 |  | $ 0 |  | $ 0 |
[1] | Recorded investment includes the unpaid principal balance and any accrued interest and net deferred fees.
[2] | Recorded investment includes principal, accrued interest and net deferred fees.
[3] | Recorded investment includes the unpaid principal balance and any accrued interest and deferred fees.

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- Definition Recorded investment in financing receivables that are 90 days or more past due and still accruing. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5111-111524 + Details
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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=28368275&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=28368275&loc=d3e5258-111524 + Details
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