Note 7 - Derivatives and Hedging Activities - Changes in Fair Values of Derivative Financial Instruments (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Amount of loss recognized in other comprehensive income, net of tax	$ (335,760)	$ (188,613)	$ 11,708,770
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Unrealized loss at beginning of period, net of tax	(799,421)	(399,367)
Amount of loss recognized in other comprehensive income, net of tax	(208,025)	(415,949)
Unrealized loss at end of period, net of tax	(932,156)	(799,421)	$ (399,367)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Hedge Ineffectiveness [Member]
Amount reclassified from accumulated other comprehensive income to noninterest income related to hedge ineffectiveness	(76,797)	(156)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Caplet Amortization [Member]
Amount reclassified from accumulated other comprehensive income to noninterest income related to hedge ineffectiveness	$ 152,087	$ 16,051