Note 5 - Debt Securities - Summary of Volume of state and Political Subdivision Securities Held to Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Debt securities held to maturity (at amortized cost; estimated fair value - $86,627 - 2022, $101,242 - 2021)	$ 96,163	$ 98,060
Unrealized Gains	0	3,187
Unrealized Losses	9,536	5
Debt Securities, Held-to-maturity, Fair Value	86,627	$ 101,242
TEXAS
Debt securities held to maturity (at amortized cost; estimated fair value - $86,627 - 2022, $101,242 - 2021)	15,101
Unrealized Gains	0
Unrealized Losses	1,301
Debt Securities, Held-to-maturity, Fair Value	13,800
CALIFORNIA
Debt securities held to maturity (at amortized cost; estimated fair value - $86,627 - 2022, $101,242 - 2021)	9,665
Unrealized Gains	0
Unrealized Losses	759
Debt Securities, Held-to-maturity, Fair Value	8,906
PENNSYLVANIA
Debt securities held to maturity (at amortized cost; estimated fair value - $86,627 - 2022, $101,242 - 2021)	8,479
Unrealized Gains	0
Unrealized Losses	726
Debt Securities, Held-to-maturity, Fair Value	7,753
FLORIDA
Debt securities held to maturity (at amortized cost; estimated fair value - $86,627 - 2022, $101,242 - 2021)	7,465
Unrealized Gains	0
Unrealized Losses	1,020
Debt Securities, Held-to-maturity, Fair Value	6,445
MICHIGAN
Debt securities held to maturity (at amortized cost; estimated fair value - $86,627 - 2022, $101,242 - 2021)	6,904
Unrealized Gains	0
Unrealized Losses	797
Debt Securities, Held-to-maturity, Fair Value	$ 6,107

Amount, before allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).

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