Note 14 - Commitments and Contingencies - Financial Instrument (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Commitments	$ 26,036,825	$ 28,492,555
Range of rates on fixed commitments
Minimum [Member]
Range of rates on fixed commitments
Maximum [Member]
Range of rates on fixed commitments
Variable Rate [Member]
Commitments	$ 20,969,079	21,734,994
Fixed Rate [Member]
Commitments	5,067,746	6,757,561
Loan Origination Commitments [Member]
Commitments	$ 6,940,380	$ 5,757,737
Loan Origination Commitments [Member] | Minimum [Member]
Range of rates on fixed commitments	3.75%	3.65%
Loan Origination Commitments [Member] | Maximum [Member]
Range of rates on fixed commitments	6.375%	8.25%
Loan Origination Commitments [Member] | Variable Rate [Member]
Commitments	$ 6,186,780	$ 615,000
Loan Origination Commitments [Member] | Fixed Rate [Member]
Commitments	753,600	5,142,737
Unfunded Commitments On Construction Loans [Member]
Commitments	$ 4,960,393	$ 7,233,565
Range of rates on fixed commitments
Unfunded Commitments On Construction Loans [Member] | Minimum [Member]
Range of rates on fixed commitments	3.50%	2.75%
Unfunded Commitments On Construction Loans [Member] | Maximum [Member]
Range of rates on fixed commitments	5.00%	5.13%
Unfunded Commitments On Construction Loans [Member] | Variable Rate [Member]
Commitments	$ 656,247	$ 5,618,741
Unfunded Commitments On Construction Loans [Member] | Fixed Rate [Member]
Commitments	4,304,146	1,614,824
Unfunded Commitments Under Lines Of Credit [Member]
Commitments	14,126,052	15,501,253
Unfunded Commitments Under Lines Of Credit [Member] | Variable Rate [Member]
Commitments	14,126,052	15,501,253
Unfunded Commitments Under Lines Of Credit [Member] | Fixed Rate [Member]
Commitments	0	0
Loan Commitments [Member]
Commitments	$ 26,026,825	28,492,555
Range of rates on fixed commitments
Loan Commitments [Member] | Minimum [Member]
Range of rates on fixed commitments
Loan Commitments [Member] | Maximum [Member]
Range of rates on fixed commitments
Loan Commitments [Member] | Variable Rate [Member]
Commitments	$ 20,969,079	21,734,994
Loan Commitments [Member] | Fixed Rate [Member]
Commitments	5,057,746	6,757,561
Standby Letters of Credit [Member]
Commitments	10,000
Standby Letters of Credit [Member] | Variable Rate [Member]
Commitments	0	0
Standby Letters of Credit [Member] | Fixed Rate [Member]
Commitments	$ 10,000