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Note 2 - Securities - Securities in a Continuous Loss Position (Details) - USD ($) | Jun. 30, 2021 | Dec. 31, 2020
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Securities available for sale, continuous unrealized loss position, less than 12 months | $ 294,748,000 | $ 119,073,000
Securities available for sale, continuous unrealized loss position, less than 12 months, unrealized loss | 4,424,000 | 899,000
Securities available for sale, continuous unrealized loss position, 12 months or more | 3,977,000 | 0
Securities available for sale, continuous unrealized loss position, 12 months or more, unrealized loss | 23,000 | 0
Securities available for sale, continuous unrealized loss position | 298,725,000 | 119,073,000
Securities available for sale, continuous unrealized loss position, unrealized loss | 4,447,000 | 899,000
US Government Agencies Debt Securities [Member] |  |
Securities available for sale, continuous unrealized loss position, less than 12 months | 252,288,000 | 118,650,000
Securities available for sale, continuous unrealized loss position, less than 12 months, unrealized loss | 3,900,000 | 897,000
Securities available for sale, continuous unrealized loss position, 12 months or more | 3,977,000 | 0
Securities available for sale, continuous unrealized loss position, 12 months or more, unrealized loss | 23,000 | 0
Securities available for sale, continuous unrealized loss position | 256,265,000 | 118,650,000
Securities available for sale, continuous unrealized loss position, unrealized loss | 3,923,000 | 897,000
Collateralized Mortgage Backed Securities [Member] |  |
Securities available for sale, continuous unrealized loss position, less than 12 months | 13,972,000 | 0
Securities available for sale, continuous unrealized loss position, less than 12 months, unrealized loss | 297,000 | 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 | 13,972,000 | 0
Securities available for sale, continuous unrealized loss position, unrealized loss | 297,000 | 0
Municipal General Obligation Bonds [Member] |  |
Securities available for sale, continuous unrealized loss position, less than 12 months | 19,301,000 | 0
Securities available for sale, continuous unrealized loss position, less than 12 months, unrealized loss | 127,000 | 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 | 19,301,000 | 0
Securities available for sale, continuous unrealized loss position, unrealized loss | 127,000 | 0
Municipal Revenue Bonds [Member] |  |
Securities available for sale, continuous unrealized loss position, less than 12 months | 9,187,000 | 423,000
Securities available for sale, continuous unrealized loss position, less than 12 months, unrealized loss | 100,000 | 2,000
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 | 9,187,000 | 423,000
Securities available for sale, continuous unrealized loss position, unrealized loss | $ 100,000 | $ 2,000

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