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Note 8 - Loans and Related Allowance for Loan and Lease Losses - Troubled Debt Restructurings (Details) $ in Thousands | 3 Months Ended
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Mar. 31, 2018 USD ($) | Mar. 31, 2017 USD ($)
Commercial And Industrial [Member] |  |
Number of contracts | 2 | 1
Pre-modification outstanding recorded investment | $ 6,977 | $ 50
Post-modification outstanding recorded investment | $ 6,977 | $ 50
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member] |  |
Number of contracts | 2 | 2
Pre-modification outstanding recorded investment | $ 63 | $ 36
Post-modification outstanding recorded investment | $ 63 | $ 36
Extended Maturity [Member] | Commercial And Industrial [Member] |  |
Number of contracts | 2 | 1
Extended Maturity [Member] | Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member] |  |
Number of contracts | 2 | 2
Other Restructurings [Member] | Commercial And Industrial [Member] |  |
Number of contracts |  |
Other Restructurings [Member] | Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member] |  |
Number of contracts |  |

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- Definition Number of financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524 + Details
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- Definition Post-modification amount of investment in financing receivables modified by troubled debt restructurings. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524 + Details
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- Definition Pre-modification amount of investment in financing receivables modified by troubled debt restructurings. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524 + Details
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