Note 15 - Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Allowance for loan losses	$ 721,765	$ 720,047
Unrealized losses on AFS securities	135,038	77,931
Board of Directors retirement plan	239,957	232,748
Other, net	311,762	155,858
Deferred compensation	215,033	183,155
Accrued bonus	216,254	258,069
Purchase accounting		4,325
Organizational costs	70,638	93,404
Net operating loss carryforwards	840,001	1,014,199
Total deferred tax assets	2,750,448	2,739,736
Deferred tax liabilities:
FHLB stock dividends	(52,709)	(32,412)
Depreciation and amortization	(276,802)	(336,613)
Loan origination costs	(195,770)	(179,185)
Purchase accounting	(28,239)
Total deferred tax liabilities	(553,520)	(548,210)
Net deferred tax asset	$ 2,196,928	$ 2,191,526