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Note 2 - Securities - Securities in a Continuous Loss Position (Details) - USD ($) | Sep. 30, 2019 | Dec. 31, 2018
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Securities available for sale, continuous unrealized loss position, less than 12 months | $ 17,478,000 | $ 72,791,000
Securities available for sale, continuous unrealized loss position, less than 12 months, unrealized loss | 374,000 | 1,582,000
Securities available for sale, continuous unrealized loss position, 12 months or more | 74,296,000 | 205,540,000
Securities available for sale, continuous unrealized loss position, 12 months or more, unrealized loss | 723,000 | 9,775,000
Securities available for sale, continuous unrealized loss position | 91,774,000 | 278,331,000
Securities available for sale, continuous unrealized loss position, unrealized loss | 1,097,000 | 11,357,000
US Government Agencies Debt Securities [Member] |  |
Securities available for sale, continuous unrealized loss position, less than 12 months | 15,630,000 | 31,220,000
Securities available for sale, continuous unrealized loss position, less than 12 months, unrealized loss | 370,000 | 1,136,000
Securities available for sale, continuous unrealized loss position, 12 months or more | 53,935,000 | 136,445,000
Securities available for sale, continuous unrealized loss position, 12 months or more, unrealized loss | 588,000 | 8,206,000
Securities available for sale, continuous unrealized loss position | 69,565,000 | 167,665,000
Securities available for sale, continuous unrealized loss position, unrealized loss | 958,000 | 9,342,000
Collateralized Mortgage Backed Securities [Member] |  |
Securities available for sale, continuous unrealized loss position, less than 12 months | 0 | 11,460,000
Securities available for sale, continuous unrealized loss position, less than 12 months, unrealized loss | 0 | 136,000
Securities available for sale, continuous unrealized loss position, 12 months or more | 17,049,000 | 23,762,000
Securities available for sale, continuous unrealized loss position, 12 months or more, unrealized loss | 116,000 | 656,000
Securities available for sale, continuous unrealized loss position | 17,049,000 | 35,222,000
Securities available for sale, continuous unrealized loss position, unrealized loss | 116,000 | 792,000
Municipal General Obligation Bonds [Member] |  |
Securities available for sale, continuous unrealized loss position, less than 12 months | 1,848,000 | 28,923,000
Securities available for sale, continuous unrealized loss position, less than 12 months, unrealized loss | 4,000 | 299,000
Securities available for sale, continuous unrealized loss position, 12 months or more | 2,758,000 | 43,961,000
Securities available for sale, continuous unrealized loss position, 12 months or more, unrealized loss | 18,000 | 866,000
Securities available for sale, continuous unrealized loss position | 4,606,000 | 72,884,000
Securities available for sale, continuous unrealized loss position, unrealized loss | 22,000 | 1,165,000
Municipal Revenue Bonds [Member] |  |
Securities available for sale, continuous unrealized loss position, less than 12 months | 0 | 1,188,000
Securities available for sale, continuous unrealized loss position, less than 12 months, unrealized loss | 0 | 11,000
Securities available for sale, continuous unrealized loss position, 12 months or more | 554,000 | 1,372,000
Securities available for sale, continuous unrealized loss position, 12 months or more, unrealized loss | 1,000 | 47,000
Securities available for sale, continuous unrealized loss position | 554,000 | 2,560,000
Securities available for sale, continuous unrealized loss position, unrealized loss | 1,000 | 58,000
Other Debt and Equity Securities [Member] |  |
Securities available for sale, continuous unrealized loss position, less than 12 months | 0 | 0
Securities available for sale, continuous unrealized loss position, less than 12 months, unrealized loss | 0 | 0
Securities available for sale, continuous unrealized loss position, 12 months or more | 0 | 0
Securities available for sale, continuous unrealized loss position, 12 months or more, unrealized loss | 0 | 0
Securities available for sale, continuous unrealized loss position | 0 | 0
Securities available for sale, continuous unrealized loss position, unrealized loss | $ 0 | $ 0

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