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Note 5 - Fair Value Measurements - Assets Measured on a Recurring Basis (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Total debt securities	$ 169,895,000	$ 170,779,000
Equity securities	895,000	955,000
Investment securities available for sale, at fair value	169,895,000	170,779,000
Subordinated Debt Securities [Member]
Total debt securities	32,533,000	31,919,000
Investment securities available for sale, at fair value	32,533,000	31,919,000
Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]
Total debt securities	7,895,000	6,318,000
Investment securities available for sale, at fair value	7,895,000	6,318,000
Fair Value, Recurring [Member]
Total debt securities	169,895,000	170,779,000
Equity securities	785,000	814,000
Total	170,680,000	171,593,000
Investment securities available for sale, at fair value	169,895,000	170,779,000
Fair Value, Recurring [Member] | Subordinated Debt Securities [Member]
Total debt securities	32,533,000	31,919,000
Investment securities available for sale, at fair value	32,533,000	31,919,000
Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]
Total debt securities	129,467,000	132,542,000
Investment securities available for sale, at fair value	129,467,000	132,542,000
Fair Value, Recurring [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]
Total debt securities	7,895,000	6,318,000
Investment securities available for sale, at fair value	7,895,000	6,318,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Total debt securities	0	0
Equity securities	785,000	814,000
Total	785,000	814,000
Investment securities available for sale, at fair value	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Subordinated Debt Securities [Member]
Total debt securities	0	0
Investment securities available for sale, at fair value	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US States and Political Subdivisions Debt Securities [Member]
Total debt securities	0	0
Investment securities available for sale, at fair value	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]
Total debt securities	0	0
Investment securities available for sale, at fair value	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Total debt securities	163,245,000	161,978,000
Equity securities	0	0
Total	163,245,000	161,978,000
Investment securities available for sale, at fair value	163,245,000	161,978,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Subordinated Debt Securities [Member]
Total debt securities	25,883,000	23,118,000
Investment securities available for sale, at fair value	25,883,000	23,118,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US States and Political Subdivisions Debt Securities [Member]
Total debt securities	129,467,000	132,542,000
Investment securities available for sale, at fair value	129,467,000	132,542,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]
Total debt securities	7,895,000	6,318,000
Investment securities available for sale, at fair value	7,895,000	6,318,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Total debt securities	6,650,000	8,801,000
Equity securities	0	0
Total	6,650,000	8,801,000
Investment securities available for sale, at fair value	6,650,000	8,801,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Subordinated Debt Securities [Member]
Total debt securities	6,650,000	8,801,000
Investment securities available for sale, at fair value	6,650,000	8,801,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | US States and Political Subdivisions Debt Securities [Member]
Total debt securities	0	0
Investment securities available for sale, at fair value	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]
Total debt securities	0	0
Investment securities available for sale, at fair value	$ 0	$ 0

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