Note 23 - Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Loss (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Before tax amount	$ (535,769)	$ (564,924)
Tax effect	104,734	112,168
Net-of-tax amount	84,631,882	80,478,592	$ 74,891,493	$ 69,974,380
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Before tax amount	1,092,554	(1,836,462)
Accumulated Other Comprehensive Income (Loss), Derivative Qualifying as Hedge, Excluded Component, Including Portion Attributable to Noncontrolling Interest [Member]
Before tax amount	(1,628,323)	1,271,538
AOCI Attributable to Parent [Member]
Net-of-tax amount	$ (431,035)	$ (452,756)	$ (206,193)	$ (1,309,241)