Note 12 - Derivative Financial Instruments (Details Textual) - USD ($)	9 Months Ended
	Sep. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2017
First Interest Rate Swap [Member]
Derivative, Notional Amount				$ 50,000,000
Derivative, Fixed Interest Rate				2.12%
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Parent, Total	$ 1,255,540
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax, Parent, Total	429,749
Second Interest Rate Swap [Member]
Derivative, Notional Amount		$ 10,300,000
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Parent, Total	549,889
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax, Parent, Total	188,217
Derivative, Variable Interest Rate		4.09%
Second Interest Rate Swap [Member] | London Interbank Offered Rate (LIBOR) [Member]
Derivative, Basis Spread on Variable Rate		1.45%
Interest Rate Swap [Member]
Derivative, Notional Amount	50,000,000
Derivative, Collateral, Obligation to Return Cash	$ 2,500,000		$ 1,500,000