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Note 2 - Securities - Investments in an Unrealized Loss Position That Were Temporarily Impaired (Details) - USD ($) $ in Thousands | Sep. 30, 2023 | Dec. 31, 2022
--- | --- | ---
Less than 12 months, fair value, available for sale securities | $ 9,818 | $ 61,012
Less than 12 months, unrealized (loss), available for sale securities | (419) | (5,458)
12 months or more, fair value, available for sale securities | 132,825 | 90,892
12 months or more, unrealized (loss), available for sale securities | (27,969) | (18,560)
Total, fair value, available for sale securities | 142,643 | 151,904
Total, unrealized (loss), available for sale securities | (28,388) | (24,018)
Less than 12 months, fair value, held to maturity securities |  | 88,617
Less than 12 months, fair value, held to maturity securities |  | (8,466)
12 months or more, fair value, held to maturity securities |  | 53,181
12 months or more, unrealized (loss), available for sale securities |  | (2,895)
Total, fair value, held to maturity securities |  | 141,798
Total, unrealized (loss), held to maturity securities |  | (11,361)
Less than 12 months, fair value |  | 149,629
Less than 12 months, fair value, |  | (13,924)
12 months or more, fair value |  | 144,073
12 months or more, unrealized (loss) |  | (21,455)
Total, fair value |  | 293,702
Total, unrealized (loss) |  | (35,379)
US Treasury Securities [Member] |  |
Less than 12 months, fair value, available for sale securities | 0 | 9,041
Less than 12 months, unrealized (loss), available for sale securities | 0 | (932)
12 months or more, fair value, available for sale securities | 11,113 | 2,188
12 months or more, unrealized (loss), available for sale securities | (1,361) | (307)
Total, fair value, available for sale securities | 11,113 | 11,229
Total, unrealized (loss), available for sale securities | (1,361) | (1,239)
Less than 12 months, fair value, held to maturity securities |  | 19,302
Less than 12 months, fair value, held to maturity securities |  | (258)
12 months or more, fair value, held to maturity securities |  | 18,342
12 months or more, unrealized (loss), available for sale securities |  | (310)
Total, fair value, held to maturity securities |  | 37,644
Total, unrealized (loss), held to maturity securities |  | (568)
US Agency and Mortgage-backed Securities [Member] |  |
Less than 12 months, fair value, available for sale securities | 2,065 | 27,282
Less than 12 months, unrealized (loss), available for sale securities | (37) | (1,945)
12 months or more, fair value, available for sale securities | 77,201 | 62,342
12 months or more, unrealized (loss), available for sale securities | (15,623) | (11,204)
Total, fair value, available for sale securities | 79,266 | 89,624
Total, unrealized (loss), available for sale securities | (15,660) | (13,149)
Less than 12 months, fair value, held to maturity securities |  | 58,019
Less than 12 months, fair value, held to maturity securities |  | (6,848)
12 months or more, fair value, held to maturity securities |  | 32,167
12 months or more, unrealized (loss), available for sale securities |  | (2,341)
Total, fair value, held to maturity securities |  | 90,186
Total, unrealized (loss), held to maturity securities |  | (9,189)
US States and Political Subdivisions Debt Securities [Member] |  |
Less than 12 months, fair value, available for sale securities | 7,753 | 24,689
Less than 12 months, unrealized (loss), available for sale securities | (382) | (2,581)
12 months or more, fair value, available for sale securities | 44,511 | 26,362
12 months or more, unrealized (loss), available for sale securities | (10,985) | (7,049)
Total, fair value, available for sale securities | 52,264 | 51,051
Total, unrealized (loss), available for sale securities | $ (11,367) | (9,630)
Less than 12 months, fair value, held to maturity securities |  | 8,648
Less than 12 months, fair value, held to maturity securities |  | (1,008)
12 months or more, fair value, held to maturity securities |  | 2,672
12 months or more, unrealized (loss), available for sale securities |  | (244)
Total, fair value, held to maturity securities |  | 11,320
Total, unrealized (loss), held to maturity securities |  | (1,252)
Corporate Debt Securities [Member] |  |
Less than 12 months, fair value, held to maturity securities |  | 2,648
Less than 12 months, fair value, held to maturity securities |  | (352)
12 months or more, fair value, held to maturity securities |  | 0
12 months or more, unrealized (loss), available for sale securities |  | 0
Total, fair value, held to maturity securities |  | 2,648
Total, unrealized (loss), held to maturity securities |  | $ (352)

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