Note 10 - Income Taxes - Deferred Taxes (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Allowances for loan losses	$ 1,492,558	$ 1,952,433
Writedowns on foreclosed assets held for sale	86,610	681,281
Deferred loan fees/costs	168,961	141,418
Unrealized depreciation on available-for-sale securities	215,317	768,879
Tax Credits	445,151	441,908
Other	71,395	66,486
	2,479,992	4,052,405
Deferred tax liabilities:
FHLB stock dividends	(32,035)	(46,481)
Unrealized appreciation on interest rate swaps	(144,765)
Accumulated depreciation	(544,560)	(470,883)
Other	(31,458)	(60,906)
	(752,818)	(578,270)
Net deferred tax asset	$ 1,727,174	$ 3,474,135