Note 11 - Long-term Debt (Details Textual) - Bank of America [Member] - USD ($)	1 Months Ended
	Oct. 31, 2015	Sep. 30, 2019
Line of Credit Facility, Maximum Borrowing Capacity	$ 110,000,000	$ 60,000,000
London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate	1.40%
Base Rate [Member]
Debt Instrument, Basis Spread on Variable Rate	0.40%