Note 8 - Loans and Allowance for Credit Losses - Recorded Investment in Loans and the Related Allowances (Details) - USD ($)	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Dec. 31, 2018
Balance	$ 2,627,738	$ 2,472,446
Provision for loan losses	130,000	125,500
Loans charged off	(270,740)	(42,918)
Recoveries of loans previously charged off	141,367	15,505
Balance	2,628,365	2,570,533
Loans individually evaluated for Impairment			$ 1,018,584	$ 1,410,513
Gross loans			238,421,622	238,554,157
Loans collectively evaluated for Impairment			237,315,178	237,050,217
Loans individually evaluated for Impairment			125,512	199,496
Allowance for loan losses	2,628,365	2,472,446	2,628,365	2,627,738
Loans collectively evaluated for Impairment			2,499,255	2,410,425
Financial Asset Acquired with Credit Deterioration [Member]
Balance	17,817
Balance	3,598
Gross loans			87,860	93,427
Allowance for loan losses	3,598		3,598	17,817
Residential Portfolio Segment [Member]
Gross loans			151,855,869	148,555,764
Residential Portfolio Segment [Member] \| One- to Four-family Loan [Member]
Balance	1,761,736	1,477,419
Provision for loan losses	71,605	114,187
Loans charged off	(236,220)	(6,724)
Recoveries of loans previously charged off	126,344	4,441
Balance	1,723,465	1,589,323
Loans individually evaluated for Impairment			574,262	955,317
Gross loans			145,180,143	141,779,340
Loans collectively evaluated for Impairment			144,518,021	140,730,596
Loans individually evaluated for Impairment			86,591	160,822
Allowance for loan losses	1,761,736	1,477,419	1,723,465	1,761,736
Loans collectively evaluated for Impairment			1,633,276	1,583,097
Residential Portfolio Segment [Member] \| One- to Four-family Loan [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Balance	17,817
Balance	3,598
Gross loans			87,860	93,427
Allowance for loan losses	3,598		3,598	17,817
Residential Portfolio Segment [Member] \| Multi-family Loans [Member]
Balance	26,562	21,970
Provision for loan losses	(3,835)	(816)
Loans charged off	0	0
Recoveries of loans previously charged off	3,971	3,972
Balance	26,698	25,126
Loans individually evaluated for Impairment			0	0
Gross loans			6,675,726	6,776,424
Loans collectively evaluated for Impairment			6,675,726	6,776,424
Loans individually evaluated for Impairment			0	0
Allowance for loan losses	26,562	21,970	26,698	26,562
Loans collectively evaluated for Impairment			26,698	26,562
Residential Portfolio Segment [Member] \| Multi-family Loans [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Balance	0
Balance	0
Gross loans			0	0
Allowance for loan losses	0		0	0
Nonresidential Real Estate Portfolio Segment [Member]
Balance	343,663	371,093
Provision for loan losses	(25,809)	1,187
Loans charged off
Recoveries of loans previously charged off	0
Balance	317,854	372,280
Loans individually evaluated for Impairment			444,322	455,196
Gross loans			31,440,008	35,286,236
Loans collectively evaluated for Impairment			30,995,686	34,831,040
Loans individually evaluated for Impairment			38,921	38,674
Allowance for loan losses	343,663	371,093	317,854	343,663
Loans collectively evaluated for Impairment			278,933	304,989
Nonresidential Real Estate Portfolio Segment [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Balance	0
Balance	0
Gross loans			0	0
Allowance for loan losses	0		0	0
Commercial Portfolio Segment [Member]
Balance	135,165	153,596
Provision for loan losses	10,492	(521)
Loans charged off	0	0
Recoveries of loans previously charged off	0	0
Balance	145,657	153,075
Loans individually evaluated for Impairment
Gross loans			18,210,794	17,241,698
Loans collectively evaluated for Impairment			18,210,794	17,241,698
Loans individually evaluated for Impairment			0	0
Allowance for loan losses	135,165	153,596	145,657	135,165
Loans collectively evaluated for Impairment			145,657	135,165
Commercial Portfolio Segment [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Balance	0
Balance	0
Gross loans			0	0
Allowance for loan losses	0		0	0
Consumer Portfolio Segment [Member]
Balance	82,947	140,269
Provision for loan losses	41,985	(44,411)
Loans charged off
Recoveries of loans previously charged off	353	1,727
Balance	125,285	97,585
Loans individually evaluated for Impairment			0	0
Gross loans			16,708,018	15,390,263
Loans collectively evaluated for Impairment			16,708,018	15,390,263
Loans individually evaluated for Impairment			0	0
Allowance for loan losses	82,947	140,269	125,285	82,947
Loans collectively evaluated for Impairment			125,285	82,947
Consumer Portfolio Segment [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Balance	0
Balance	0
Gross loans			0	0
Allowance for loan losses	0		0	0
Purchased Auto Loans [Member]
Balance	277,665	308,099
Provision for loan losses	35,562	55,874
Loans charged off	(34,520)	(36,194)
Recoveries of loans previously charged off	10,699	5,365
Balance	289,406	333,144
Loans individually evaluated for Impairment
Gross loans			20,206,933	22,080,196
Loans collectively evaluated for Impairment			20,206,933	22,080,196
Loans individually evaluated for Impairment
Allowance for loan losses	277,665	$ 308,099	289,406	277,665
Loans collectively evaluated for Impairment			289,406	277,665
Purchased Auto Loans [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Balance	0
Balance	0
Gross loans			0	0
Allowance for loan losses	$ 0		$ 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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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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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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