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Note 2 - Securities - Securities in a Continuous Loss Position (Details) - USD ($) | Jun. 30, 2022 | Dec. 31, 2021
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Securities available for sale, continuous unrealized loss position, less than 12 months | $ 303,956,000 | $ 351,062,000
Securities available for sale, continuous unrealized loss position, less than 12 months, unrealized loss | 26,292,000 | 6,455,000
Securities available for sale, continuous unrealized loss position, 12 months or more | 265,186,000 | 110,491,000
Securities available for sale, continuous unrealized loss position, 12 months or more, unrealized loss | 34,311,000 | 3,503,000
Securities available for sale, continuous unrealized loss position | 569,142,000 | 461,553,000
Securities available for sale, continuous unrealized loss position, unrealized loss | 60,603,000 | 9,958,000
US Government Agencies Debt Securities [Member] |  |
Securities available for sale, continuous unrealized loss position, less than 12 months | 176,893,000 | 274,287,000
Securities available for sale, continuous unrealized loss position, less than 12 months, unrealized loss | 17,028,000 | 5,274,000
Securities available for sale, continuous unrealized loss position, 12 months or more | 230,442,000 | 110,053,000
Securities available for sale, continuous unrealized loss position, 12 months or more, unrealized loss | 29,149,000 | 3,495,000
Securities available for sale, continuous unrealized loss position | 407,335,000 | 384,340,000
Securities available for sale, continuous unrealized loss position, unrealized loss | 46,177,000 | 8,769,000
Collateralized Mortgage-Backed Securities [Member] |  |
Securities available for sale, continuous unrealized loss position, less than 12 months | 23,935,000 | 23,184,000
Securities available for sale, continuous unrealized loss position, less than 12 months, unrealized loss | 2,259,000 | 652,000
Securities available for sale, continuous unrealized loss position, 12 months or more | 11,372,000 | 24,000
Securities available for sale, continuous unrealized loss position, 12 months or more, unrealized loss | 2,109,000 | 0
Securities available for sale, continuous unrealized loss position | 35,307,000 | 23,208,000
Securities available for sale, continuous unrealized loss position, unrealized loss | 4,368,000 | 652,000
Municipal General Obligation Bonds [Member] |  |
Securities available for sale, continuous unrealized loss position, less than 12 months | 90,305,000 | 40,748,000
Securities available for sale, continuous unrealized loss position, less than 12 months, unrealized loss | 5,551,000 | 392,000
Securities available for sale, continuous unrealized loss position, 12 months or more | 16,284,000 | 0
Securities available for sale, continuous unrealized loss position, 12 months or more, unrealized loss | 1,968,000 | 0
Securities available for sale, continuous unrealized loss position | 106,589,000 | 40,748,000
Securities available for sale, continuous unrealized loss position, unrealized loss | 7,519,000 | 392,000
Municipal Revenue Bonds [Member] |  |
Securities available for sale, continuous unrealized loss position, less than 12 months | 12,823,000 | 12,843,000
Securities available for sale, continuous unrealized loss position, less than 12 months, unrealized loss | 1,454,000 | 137,000
Securities available for sale, continuous unrealized loss position, 12 months or more | 7,088,000 | 414,000
Securities available for sale, continuous unrealized loss position, 12 months or more, unrealized loss | 1,085,000 | 8,000
Securities available for sale, continuous unrealized loss position | 19,911,000 | 13,257,000
Securities available for sale, continuous unrealized loss position, unrealized loss | $ 2,539,000 | $ 145,000

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