Note 4 - Loans (Details Textual)	3 Months Ended	12 Months Ended
Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Loans and Leases Receivable, Gross	$ 488,169,810		$ 486,381,167
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums			2,323,000
Loans and Leases Receivable, Deferred Income	606,635		719,565
Financing Receivable, Nonaccrual	4,964,914		4,994,914
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	59,182		219,734
Impaired Financing Receivable, Related Allowance	281,910		281,910
Financing Receivable, Allowance for Credit Loss, Writeoff	(0)	$ (0)	18,970
Financing Receivable, Deferred Payments, Subsequent Additional Deferrals	$ 4,300,000
Financing Receivable, Percent of Outstanding Loan Balance Additional Deferred	1.00%
Certain Loans Acquired in Transfer, Nonaccretable Difference	$ 241,587
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Reclassifications from Nonaccretable Difference	225,000
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield	1,418,079		1,629,242
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Accretion	211,163
Certain Loans Acquired in Transfer, Accretable Yield	1,257,038
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	96,265,413
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	95,862,785
Mortgage Loans in Process of Foreclosure, Amount	0
Financial Asset Acquired with Credit Deterioration [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield	86,342
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Accretion	54,266
Nonaccrual Loans [Member]
Impaired Financing Receivable, Related Allowance	281,910		281,910
Allowance for Loan and Lease Losses Write-offs, Net	27,146		27,146
Commercial Portfolio Segment [Member]
Loans and Leases Receivable, Gross	26,374,885		$ 31,182,206
Financing Receivable, Number of Loans, Nonaccrual Status			1
Financing Receivable, Nonaccrual	152,449		$ 152,449
Impaired Financing Receivable, Related Allowance	152,449		$ 152,449
Number of Loans Classified as TDR			1
Financing Receivable, Allowance for Credit Loss, Writeoff	(0)	(0)	$ (0)
Commercial Real Estate Portfolio Segment [Member]
Loans and Leases Receivable, Gross	$ 329,179,712		$ 319,185,116
Financing Receivable, Number of Loans, Nonaccrual Status	2		2
Financing Receivable, Nonaccrual	$ 4,780,965		$ 4,810,965
Impaired Financing Receivable, Related Allowance	$ 129,461		$ 129,461
Number of Loans Classified as TDR	2		1
Financing Receivable, Troubled Debt Restructuring	$ 6,278,069		$ 2,009,967
Financing Receivable, Troubled Debt Restructuring, Premodification	4,278,004
Financing Receivable, Allowance for Credit Loss, Writeoff	(0)	(0)	(0)
Residential Portfolio Segment [Member]
Loans and Leases Receivable, Gross	$ 111,993,662		107,436,033
Financing Receivable, Number of Loans, Nonaccrual Status	1
Financing Receivable, Nonaccrual	$ 31,500		31,500
Impaired Financing Receivable, Related Allowance	$ 0		$ 0
Number of Loans Classified as TDR	1		1
Financing Receivable, Troubled Debt Restructuring	$ 37,341		$ 39,228
Financing Receivable, Allowance for Credit Loss, Writeoff	(0)	(0)	18,970
SBA CARES Act Paycheck Protection Program [Member] \| Commercial Portfolio Segment [Member]
Loans and Leases Receivable, Gross	4,200,000		9,700,000
Financing Receivable, Loans Originated Amount			$ 60,000,000	$ 60,000,000
Interest Income, Financing Receivable, before Allowance for Credit Loss	105,000	$ 369,000
Loans and Leases Receivable, Deferred Income	$ 91,000

Amount of financing receivable modified related to the COVID-19 subsequent granted additional deferrals.

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Represents the number of loans in financing receivables that are on nonaccrual status as of the balance sheet date.

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Amount, after recoveries, of loans and leases that have been written-off.

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The aggregate excess of a loan's cash flows expected to be collected over the investor's initial investment in the loan. This relates to loans with deteriorating of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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The amount of the loan's contractually required payments receivable in excess of the amount of its cash flows expected to be collected. This relates to loans with deteriorating of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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Amount of the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality.

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Amount of accretion recognized for the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities, with evidence of deterioration of credit quality.

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Amount of increase of reclassification from nonaccretable difference to the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality.

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The recorded balance, net of any applicable reductions (for example, unamortized accretable yield and allowance for loan losses). This relates to loans not accounted for debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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The undiscounted sum of all amounts, including amounts deemed principal, interest, fees, penalties, and other under the loan, owed to the investor at the reporting date, whether or not currently due and whether or not any such amounts have been written or charged off by the investor. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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Amount of writeoff of financing receivable, charged against allowance for credit loss.

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Amount, before troubled debt restructuring, of financing receivable to be modified.

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Amount of financing receivable modified as troubled debt restructuring.

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Amortized cost of financing receivable on nonaccrual status. Excludes net investment in lease.

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Amount of allowance for credit losses related to recorded investment.

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Amount of interest income from financing receivable before allowance for credit loss.

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Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

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