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Note 4 - Investment and Equity Securities - Gross Unrealized Losses and Fair Value (Details) - USD ($) $ in Thousands | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | ---
Less than Twelve Months, Fair Value | $ 94,134 | $ 33,423
Less than Twelve Months, Gross Unrealized Losses | (12,097) | (441)
Twelve Months or Greater, Fair Value | 51,244 | 2,711
Twelve Months or Greater, Gross Unrealized Losses | (15,986) | (99)
Total, Fair Value | 145,378 | 36,134
Total, Gross Unrealized Losses | (28,083) | (540)
Subordinated Debt Securities [Member] |  |
Less than Twelve Months, Fair Value | 12,638 | 9,150
Less than Twelve Months, Gross Unrealized Losses | (1,129) | (100)
Twelve Months or Greater, Fair Value | 8,790 | 731
Twelve Months or Greater, Gross Unrealized Losses | (1,010) | (19)
Total, Fair Value | 21,428 | 9,881
Total, Gross Unrealized Losses | (2,139) | (119)
Nontaxable Municipal Bonds [Member] |  |
Less than Twelve Months, Fair Value | 75,343 | 24,273
Less than Twelve Months, Gross Unrealized Losses | (10,488) | (341)
Twelve Months or Greater, Fair Value | 41,138 | 0
Twelve Months or Greater, Gross Unrealized Losses | (14,623) | 0
Total, Fair Value | 116,481 | 24,273
Total, Gross Unrealized Losses | (25,111) | (341)
Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member] |  |
Less than Twelve Months, Fair Value | 6,153 | 0
Less than Twelve Months, Gross Unrealized Losses | (480) | 0
Twelve Months or Greater, Fair Value | 1,316 | 1,980
Twelve Months or Greater, Gross Unrealized Losses | (353) | (80)
Total, Fair Value | 7,469 | 1,980
Total, Gross Unrealized Losses | $ (833) | $ (80)

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