Note 4 - Loans and Allowance for Credit Losses - Components of Loans, Net of Deferred Loan Costs (Fees) (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Gross loans	$ 250,713,446	$ 238,554,157
Less: Allowance for loan losses	(2,937,632)	(2,627,738)	$ (2,472,446)
Loans, net	247,775,814	235,926,419
Residential Portfolio Segment [Member]
Gross loans	161,004,509	148,555,764
Residential Portfolio Segment [Member] \| One- to Four-family Loan [Member]
Gross loans	155,143,081	141,779,340
Less: Allowance for loan losses	(2,121,082)	(1,761,736)	(1,477,419)
Residential Portfolio Segment [Member] \| Multi-family Loans [Member]
Gross loans	5,861,428	6,776,424
Less: Allowance for loan losses	(24,333)	(26,562)	(21,970)
Nonresidential Real Estate Portfolio Segment [Member]
Gross loans	30,679,614	35,286,236
Less: Allowance for loan losses	(207,410)	(343,663)	(371,093)
Commercial Portfolio Segment [Member]
Gross loans	23,915,335	17,241,698
Less: Allowance for loan losses	(198,565)	(135,165)	(153,596)
Consumer Portfolio Segment [Member]
Gross loans	20,562,789	15,390,263
Less: Allowance for loan losses	(191,821)	(82,947)	(140,269)
Purchased Auto Loans [Member]
Gross loans	14,551,199	22,080,196
Less: Allowance for loan losses	(194,421)	(277,665)	$ (308,099)
Non-mortgage Loans [Member]
Gross loans	$ 89,708,937	$ 89,998,393

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance 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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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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