Note 12 - Derivative Financial Instruments (Details Textual) - USD ($)	3 Months Ended
	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	$ 309,013
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax, Parent, Total	105,770
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	(175,620)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax, Parent, Total	$ 60,112
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, Collateral, Obligation to Return Cash	$ 80,000	$ 1,500,000