Note 13 - Disclosures About Fair Value of Assets and Liabilities - Fair Value of Financial Instruments (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Interest-bearing demand deposits in other financial institutions	$ 213,342,950	$ 142,056,538
Reported Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	220,238,289	148,422,908
Reported Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Interest-bearing demand deposits in other financial institutions	2,455,000	4,760,089
Federal Home Loan Bank stock	4,088,700	3,896,900
Mortgage loans held for sale	7,990,141	11,359,174
Interest receivable	4,043,621	4,060,795
Deposits	1,023,136,682	938,672,541
FHLB advances	66,000,000	66,000,000
Interest payable	564,439	932,172
Reported Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Loans, net	743,220,776	742,149,271
Reported Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Subordinated Debentures Issued to Capital Trusts [Member]
Subordinated debentures	15,465,000	15,465,000
Reported Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Subordinated Notes, Net [Member]
Subordinated debentures	19,575,492	19,564,131
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	220,238,289	148,422,908
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Interest-bearing demand deposits in other financial institutions	2,455,135	4,771,605
Federal Home Loan Bank stock	4,088,700	3,896,900
Mortgage loans held for sale	8,177,951	11,626,174
Interest receivable	4,043,621	4,060,795
Deposits	1,023,880,736	939,806,149
FHLB advances	66,072,251	66,089,183
Interest payable	564,439	932,172
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Loans, net	735,178,970	737,701,011
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Subordinated Debentures Issued to Capital Trusts [Member]
Subordinated debentures	15,465,000	15,465,000
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Subordinated Notes, Net [Member]
Subordinated debentures	$ 27,001,113	$ 25,608,997

Fair value portion of interest payable.

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- Definition

Fair value portion of interest receivable.

+ References

No definition available.

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- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

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- Definition

Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

+ References

No definition available.

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- Definition

Fair value of subordinated debt obligations including, but not limited to, subordinated loan, subordinated bond, subordinated debenture or junior debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-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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- Definition

Fair value portion of borrowing from Federal Home Loan Bank (FHLBank).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.13(3)(a))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

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- Definition

For banks and other depository institutions (including Federal Reserve Banks, if applicable): Interest-bearing deposits in other financial institutions for relatively short periods of time including, for example, certificates of deposits, which are presented separately from cash on the balance sheet.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=117340910&loc=d3e59706-112781

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.2)
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

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- Definition

Fair value portion of investments in Federal Home Loan Bank (FHLBank) stock.

+ References

No definition available.

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- Definition

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-URI http://asc.fasb.org/subtopic&trid=2196772

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- Definition

Fair value portion of mortgage loans held-for-sale.

+ References

No definition available.

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