Note 12 - Derivative Financial Instruments (Details Textual) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 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		$ (752,679)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax, Parent, Total		257,629
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	$ 417,943
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax, Parent, Total	143,054
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	50,000,000
Derivative, Collateral, Obligation to Return Cash	$ 1,600,000	$ 1,600,000		$ 1,500,000