Note 18 - Fair Value Disclosure Measurements - Assets Measured on a Recurring Basis (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Total debt securities	$ 105,733,000	$ 98,322,000
Equity securities in financial institutions	710,000	616,000
Subordinated Debt Securities [Member]
Total debt securities	4,126,000
US Government Agencies Debt Securities [Member]
Total debt securities		7,471,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Total debt securities	18,630,000	17,758,000
Fair Value, Recurring [Member]
Total debt securities	105,733,000	98,322,000
Equity securities in financial institutions	710,000	616,000
Total	106,443,000	98,938,000
Fair Value, Recurring [Member] \| Subordinated Debt Securities [Member]
Total debt securities	4,126,000
Fair Value, Recurring [Member] \| US Government Agencies Debt Securities [Member]
Assets measured on a recurring basis		7,471,000
Fair Value, Recurring [Member] \| US States and Political Subdivisions Debt Securities [Member]
Total debt securities	82,977,000	73,093,000
Fair Value, Recurring [Member] \| Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Total debt securities	18,630,000	17,758,000
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Total debt securities
Equity securities in financial institutions	710,000	616,000
Total	710,000	616,000
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Subordinated Debt Securities [Member]
Total debt securities
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| US Government Agencies Debt Securities [Member]
Assets measured on a recurring basis
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| US States and Political Subdivisions Debt Securities [Member]
Total debt securities
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Total debt securities
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Total debt securities	105,733,000	98,322,000
Equity securities in financial institutions
Total	105,733,000	98,322,000
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Subordinated Debt Securities [Member]
Total debt securities	4,126,000
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| US Government Agencies Debt Securities [Member]
Assets measured on a recurring basis		7,471,000
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| US States and Political Subdivisions Debt Securities [Member]
Total debt securities	82,977,000	73,093,000
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Total debt securities	18,630,000	17,758,000
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Total debt securities
Equity securities in financial institutions
Total
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member] \| Subordinated Debt Securities [Member]
Total debt securities
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member] \| US Government Agencies Debt Securities [Member]
Assets measured on a recurring basis
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member] \| US States and Political Subdivisions Debt Securities [Member]
Total debt securities
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member] \| Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Total debt securities

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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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
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118942338&loc=SL82898722-210454

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
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-URI http://asc.fasb.org/extlink&oid=118954083&loc=d3e26610-111562

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-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=99377092&loc=SL75136599-209740

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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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