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Note 5 - Fair Value Measurements - Assets Measured on a Recurring Basis (Details) - USD ($)	Mar. 31, 2022	Dec. 31, 2021
Total debt securities	$ 175,216,000	$ 170,199,000
Equity securities in financial institutions	851,000	818,000
Investment securities available for sale, at fair value	175,216,000	170,199,000
Subordinated Debt Securities [Member]
Total debt securities	31,982,000	32,537,000
Investment securities available for sale, at fair value	31,982,000	32,537,000
Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member]
Total debt securities	9,236,000	10,317,000
Investment securities available for sale, at fair value	9,236,000	10,317,000
Fair Value, Recurring [Member]
Total debt securities	175,216,000	170,199,000
Equity securities in financial institutions	851,000	818,000
Total	176,067,000	171,017,000
Investment securities available for sale, at fair value	175,216,000	170,199,000
Fair Value, Recurring [Member] | Subordinated Debt Securities [Member]
Total debt securities	31,982,000	32,537,000
Investment securities available for sale, at fair value	31,982,000	32,537,000
Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]
Total debt securities	133,998,000	127,345,000
Investment securities available for sale, at fair value	133,998,000	127,345,000
Fair Value, Recurring [Member] | Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member]
Total debt securities	9,236,000	10,317,000
Investment securities available for sale, at fair value	9,236,000	10,317,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Total debt securities	0	0
Equity securities in financial institutions	851,000	818,000
Total	851,000	818,000
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 Securities, Issued by US Government Sponsored Enterprises [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	165,136,000	157,999,000
Equity securities in financial institutions	0	0
Total	165,136,000	157,999,000
Investment securities available for sale, at fair value	165,136,000	157,999,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Subordinated Debt Securities [Member]
Total debt securities	21,902,000	20,337,000
Investment securities available for sale, at fair value	21,902,000	20,337,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US States and Political Subdivisions Debt Securities [Member]
Total debt securities	133,998,000	127,345,000
Investment securities available for sale, at fair value	133,998,000	127,345,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member]
Total debt securities	9,236,000	10,317,000
Investment securities available for sale, at fair value	9,236,000	10,317,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Total debt securities	10,080,000	12,200,000
Equity securities in financial institutions	0	0
Total	10,080,000	12,200,000
Investment securities available for sale, at fair value	10,080,000	12,200,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Subordinated Debt Securities [Member]
Total debt securities	10,080,000	12,200,000
Investment securities available for sale, at fair value	10,080,000	12,200,000
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 Securities, Issued by US Government Sponsored Enterprises [Member]
Total debt securities	0	0
Investment securities available for sale, at fair value	$ 0	$ 0

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- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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