Note 4 - Loans and Allowance for Credit Losses - Recorded Investment in Loans and the Related Allowances (Details) - USD ($)	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Allowance for loan losses	$ 2,627,738	$ 2,472,446
Provision for loan losses	595,000	527,500
Loans charged off	(494,210)	(478,196)
Recoveries of loans previously charged off	209,104	105,988
Allowance for loan losses	2,937,632	2,627,738
Loans individually evaluated for impairment			$ 99,954	$ 199,496
Allowance for loan losses	2,627,738	2,472,446	2,937,632	2,627,738
Loans collectively evaluated for impairment			2,737,506	2,410,425
Loans individually evaluated for impairment			2,087,604	1,410,513
Gross loans			250,713,446	238,554,157
Loans collectively evaluated for impairment			248,461,084	237,050,217
Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses	17,817
Allowance for loan losses	100,172	17,817
Allowance for loan losses	17,817	17,817	100,172	17,817
Gross loans			164,758	93,427
Residential Portfolio Segment [Member]
Gross loans			161,004,509	148,555,764
Residential Portfolio Segment [Member] \| One- to Four-family Loan [Member]
Allowance for loan losses	1,761,736	1,477,419
Provision for loan losses	505,357	546,217
Loans charged off	(284,980)	(312,175)
Recoveries of loans previously charged off	138,969	50,275
Allowance for loan losses	2,121,082	1,761,736
Loans individually evaluated for impairment			90,359	160,822
Allowance for loan losses	2,121,082	1,477,419	2,121,082	1,761,736
Loans collectively evaluated for impairment			1,930,551	1,583,097
Loans individually evaluated for impairment			1,724,694	955,317
Gross loans			155,143,081	141,779,340
Loans collectively evaluated for impairment			153,253,629	140,730,596
Residential Portfolio Segment [Member] \| One- to Four-family Loan [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses	17,817
Allowance for loan losses	100,172	17,817
Allowance for loan losses	17,817	17,817	100,172	17,817
Gross loans			164,758	93,427
Residential Portfolio Segment [Member] \| Multi-family Loans [Member]
Allowance for loan losses	26,562	21,970
Provision for loan losses	(34,149)	(11,295)
Loans charged off	0	0
Recoveries of loans previously charged off	31,920	15,887
Allowance for loan losses	24,333	26,562
Loans individually evaluated for impairment
Allowance for loan losses	24,333	21,970	24,333	26,562
Loans collectively evaluated for impairment			24,333	26,562
Loans individually evaluated for impairment				0
Gross loans			5,861,428	6,776,424
Loans collectively evaluated for impairment			5,861,428	6,776,424
Residential Portfolio Segment [Member] \| Multi-family Loans [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses
Allowance for loan losses
Allowance for loan losses
Gross loans			0	0
Nonresidential Real Estate Portfolio Segment [Member]
Allowance for loan losses	343,663	371,093
Provision for loan losses	(136,253)	(27,430)
Loans charged off
Recoveries of loans previously charged off	0
Allowance for loan losses	207,410	343,663
Loans individually evaluated for impairment				38,674
Allowance for loan losses	207,410	371,093	207,410	343,663
Loans collectively evaluated for impairment			207,410	304,989
Loans individually evaluated for impairment			343,720	455,196
Gross loans			30,679,614	35,286,236
Loans collectively evaluated for impairment			30,335,894	34,831,040
Nonresidential Real Estate Portfolio Segment [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses
Allowance for loan losses
Allowance for loan losses
Gross loans			0	0
Commercial Portfolio Segment [Member]
Allowance for loan losses	135,165	153,596
Provision for loan losses	63,400	(18,431)
Loans charged off	0	0
Recoveries of loans previously charged off	0	0
Allowance for loan losses	198,565	135,165
Loans individually evaluated for impairment
Allowance for loan losses	198,565	153,596	198,565	135,165
Loans collectively evaluated for impairment			198,565	135,165
Loans individually evaluated for impairment
Gross loans			23,915,335	17,241,698
Loans collectively evaluated for impairment			23,915,335	17,241,698
Commercial Portfolio Segment [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses
Allowance for loan losses
Allowance for loan losses
Gross loans			0	0
Consumer Portfolio Segment [Member]
Allowance for loan losses	82,947	140,269
Provision for loan losses	152,566	(72,930)
Loans charged off	(47,898)
Recoveries of loans previously charged off	4,206	15,608
Allowance for loan losses	191,821	82,947
Loans individually evaluated for impairment
Allowance for loan losses	191,821	140,269	191,821	82,947
Loans collectively evaluated for impairment			191,821	82,947
Loans individually evaluated for impairment				0
Gross loans			20,562,789	15,390,263
Loans collectively evaluated for impairment			20,562,789	15,390,263
Consumer Portfolio Segment [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses
Allowance for loan losses
Allowance for loan losses
Gross loans			0	0
Purchased Auto Loans [Member]
Allowance for loan losses	277,665	308,099
Provision for loan losses	44,079	111,369
Loans charged off	(161,332)	(166,021)
Recoveries of loans previously charged off	34,009	24,218
Allowance for loan losses	194,421	277,665
Loans individually evaluated for impairment			9,595
Allowance for loan losses	194,421	308,099	194,421	277,665
Loans collectively evaluated for impairment			184,826	277,665
Loans individually evaluated for impairment			19,190
Gross loans			14,551,199	22,080,196
Loans collectively evaluated for impairment			14,532,009	22,080,196
Purchased Auto Loans [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Allowance for loan losses
Allowance for loan losses
Allowance for loan losses
Gross loans			$ 0	$ 0

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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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 of expense related to estimated loss from loan and lease transactions.

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