Note 1 - Summary of Significant Accounting Policies - Schedule of Adjustments for New Accounting Pronouncements (Details) - USD ($)	Sep. 30, 2023	Jun. 30, 2023	Jan. 01, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Total loans	$ 713,078,808		$ 721,729,711	$ 721,603,936
Allowance for credit losses	(2,785,949)	$ (2,785,949)	(3,012,949)	(2,578,174)	$ (2,428,174)	$ (2,253,174)	$ (2,153,174)
Net loans	710,292,859		718,868,762	719,025,762
Loans, allowance for credit loss	2,785,949	2,785,949	3,012,949	2,578,174	2,428,174	2,253,174	2,153,174
Loans Not Including Unfunded Commitments [Member]
Allowance for credit losses			(2,860,949)
Loans, allowance for credit loss			2,860,949
Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Total loans			125,775	125,775
Allowance for credit losses			(434,775)	(282,775)
Net loans			(157,000)	(157,000)
Loans, allowance for credit loss			434,775	282,775
Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Loans Not Including Unfunded Commitments [Member]
Allowance for credit losses			(282,775)
Loans, allowance for credit loss			282,775
Previously Reported [Member]
Total loans			721,603,936	721,729,711
Allowance for credit losses			(2,578,174)	(2,860,949)
Net loans			719,025,762	718,868,762
Loans, allowance for credit loss			2,578,174	2,860,949
Previously Reported [Member] | Loans Not Including Unfunded Commitments [Member]
Allowance for credit losses			(2,578,174)
Loans, allowance for credit loss			2,578,174
Commercial and Industrial [Member]
Total loans	5,697,696		1,684,189	1,684,189
Allowance for credit losses	(18,000)	(11,400)	(4,000)	(3,960)	(5,900)	(7,000)	(9,400)
Loans, allowance for credit loss	18,000	11,400	4,000	3,960	5,900	7,000	9,400
Commercial and Industrial [Member] | Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Total loans			0	0
Allowance for credit losses			(40)	(40)
Loans, allowance for credit loss			40	40
Commercial and Industrial [Member] | Previously Reported [Member]
Total loans			1,684,189	1,684,189
Allowance for credit losses			(3,960)
Loans, allowance for credit loss			3,960
Consumer Portfolio Segment [Member]
Total loans	19,048
Allowance for credit losses	0	0		(2,578,174)
Loans, allowance for credit loss	0	0		2,578,174
Real Estate Loan [Member] | Residential Portfolio Segment [Member]
Total loans	488,056,539		495,689,840	466,100,627
Allowance for credit losses	(1,793,827)	(1,811,547)	(1,814,203)	(1,602,534)	(1,413,774)	(1,251,924)	(1,092,474)
Loans, allowance for credit loss	1,793,827	1,811,547	1,814,203	1,602,534	1,413,774	1,251,924	1,092,474
Real Estate Loan [Member] | Residential Portfolio Segment [Member] | Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Total loans			29,589,213	29,589,213
Allowance for credit losses			(211,669)	(113,969)
Loans, allowance for credit loss			211,669	113,969
Real Estate Loan [Member] | Residential Portfolio Segment [Member] | Previously Reported [Member]
Total loans			466,100,627	495,689,840
Allowance for credit losses			(1,602,534)
Loans, allowance for credit loss			1,602,534
Real Estate Loan [Member] | Commercial and Multi-Family Real Estate [Member]
Total loans	0		0	162,338,669
Allowance for credit losses			0	(615,480)	(648,000)	(680,000)	(768,600)
Loans, allowance for credit loss			0	615,480	648,000	680,000	768,600
Real Estate Loan [Member] | Commercial and Multi-Family Real Estate [Member] | Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Total loans			(162,338,669)	(162,338,669)
Allowance for credit losses			615,480
Loans, allowance for credit loss			(615,480)
Real Estate Loan [Member] | Commercial and Multi-Family Real Estate [Member] | Previously Reported [Member]
Total loans			162,338,669	0
Allowance for credit losses			(615,480)
Loans, allowance for credit loss			615,480
Real Estate Loan [Member] | Commercial Real Estate Portfolio Segment [Member]
Total loans	99,503,713		96,030,721	0
Allowance for credit losses	(533,497)	(539,002)	(522,977)	(381,180)
Loans, allowance for credit loss	533,497	539,002	522,977	381,180
Real Estate Loan [Member] | Commercial Real Estate Portfolio Segment [Member] | Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Total loans			96,030,721	96,030,721
Allowance for credit losses			(522,977)	(141,797)
Loans, allowance for credit loss			522,977	141,797
Real Estate Loan [Member] | Commercial Real Estate Portfolio Segment [Member] | Previously Reported [Member]
Total loans			0	96,030,721
Allowance for credit losses			0
Loans, allowance for credit loss			0
Real Estate Loan [Member] | Multi-Family Real Estate [Member]
Total loans	68,264,208		66,400,713	0
Allowance for credit losses	(269,925)	(265,000)	(259,769)	(234,300)
Loans, allowance for credit loss	269,925	265,000	259,769	234,300
Real Estate Loan [Member] | Multi-Family Real Estate [Member] | Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Total loans			66,400,713	66,400,713
Allowance for credit losses			(259,769)	(25,469)
Loans, allowance for credit loss			259,769	25,469
Real Estate Loan [Member] | Multi-Family Real Estate [Member] | Previously Reported [Member]
Total loans			0	66,400,713
Allowance for credit losses			0
Loans, allowance for credit loss			0
Real Estate Loan [Member] | Construction Loans [Member]
Total loans	51,537,604		61,825,478	61,825,478
Allowance for credit losses	(170,700)	(159,000)	(260,000)	(258,500)	(268,500)	(232,000)	(195,000)
Loans, allowance for credit loss	170,700	$ 159,000	260,000	258,500	268,500	232,000	195,000
Real Estate Loan [Member] | Construction Loans [Member] | Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Total loans			0	0
Allowance for credit losses			(1,500)	(1,500)
Loans, allowance for credit loss			1,500	1,500
Real Estate Loan [Member] | Construction Loans [Member] | Previously Reported [Member]
Total loans			61,825,478	61,825,478
Allowance for credit losses			(258,500)
Loans, allowance for credit loss			258,500
Real Estate Loan [Member] | Commercial and Industrial [Member]
Allowance for credit losses				(3,960)
Loans, allowance for credit loss				3,960
Home Equity Loan [Member] | Consumer Portfolio Segment [Member]
Total loans	0		0	29,654,973
Allowance for credit losses	0		0	(97,700)	(92,000)	(82,250)	(87,700)
Loans, allowance for credit loss	0		0	97,700	$ 92,000	$ 82,250	$ 87,700
Home Equity Loan [Member] | Consumer Portfolio Segment [Member] | Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Total loans			(29,654,973)	(29,654,973)
Allowance for credit losses			97,700	0
Loans, allowance for credit loss			(97,700)	0
Home Equity Loan [Member] | Consumer Portfolio Segment [Member] | Previously Reported [Member]
Total loans			29,654,973	0
Allowance for credit losses			(97,700)
Loans, allowance for credit loss			97,700
Consumer Loans [Member] | Consumer Portfolio Segment [Member]
Total loans	$ 19,048		98,770	0
Consumer Loans [Member] | Consumer Portfolio Segment [Member] | Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Total loans			98,770	98,770
Consumer Loans [Member] | Consumer Portfolio Segment [Member] | Previously Reported [Member]
Total loans			0	$ 98,770
Unfunded Loan Commitment [Member]
Allowance for credit losses			(152,000)
Loans, allowance for credit loss			152,000
Unfunded Loan Commitment [Member] | Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Allowance for credit losses			(152,000)
Loans, allowance for credit loss			152,000
Unfunded Loan Commitment [Member] | Previously Reported [Member]
Allowance for credit losses			0
Loans, allowance for credit loss			$ 0