Note 7 - Outstanding Loan Commitments, Unused Lines of Credit, and Letters of Credit (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Letter of Credit [Member]
Outstanding loan commitments, unused lines of credit, and letters of credit	$ 1,905,553	$ 1,827,513
Loan Origination Commitments [Member]
Outstanding loan commitments, unused lines of credit, and letters of credit	12,354,870	9,433,500
Unused lines of Credit [Member]
Outstanding loan commitments, unused lines of credit, and letters of credit	26,984,173	40,005,063
Unused lines of Credit [Member] | Home Equity Loan [Member]
Outstanding loan commitments, unused lines of credit, and letters of credit	3,594,847	3,390,515
Unused lines of Credit [Member] | Commercial Lines [Member]
Outstanding loan commitments, unused lines of credit, and letters of credit	23,389,326	36,614,548
Construction and Land Development [Member] | Loan Origination Commitments [Member]
Outstanding loan commitments, unused lines of credit, and letters of credit	6,800,240
Commercial Portfolio Segment [Member] | Loan Origination Commitments [Member]
Outstanding loan commitments, unused lines of credit, and letters of credit	1,143,217	1,295,000
Commercial Real Estate Portfolio Segment [Member] | Loan Origination Commitments [Member]
Outstanding loan commitments, unused lines of credit, and letters of credit	2,853,913	7,478,500
Residential Portfolio Segment [Member] | Loan Origination Commitments [Member]
Outstanding loan commitments, unused lines of credit, and letters of credit	$ 1,557,500	$ 660,000