Note 2 - Securities (Details Textual)	12 Months Ended
Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Equity Securities, FV-NI, Current	$ 5,000	$ 15,000
Equity Securities, FV-NI, Unrealized Gain (Loss), Total	(10,000)	(4,000)
Debt Securities, Available-for-sale, Restricted	$ 51,000,000.0	$ 36,000,000.0
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions	126
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions	4
Other-than-temporary Impairment Loss, Debt Securities, Available-for-sale, Total	$ 0
US States and Political Subdivisions Debt Securities [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions	71
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions	28
Corporate Debt Securities [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions	17
Collateralized Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions	7
US Government Agencies Debt Securities [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions	3

Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without an allowance for credit loss. Includes beneficial interest in securitized financial asset.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455

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

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