Note 11 - Derivative Financial Instruments - Effect of Derivative Instruments on Consolidated Statements of Income (Details) - Interest Rate Swap [Member] - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net gain (loss)	[1]	$ 515	$ (407)	$ 2,907	$ (913)
Not Designated as Hedging Instrument [Member]
Net gain (loss)		668	(56)	2,382	(316)
Designated as Hedging Instrument [Member] | Fair Value Hedging [Member]
Net gain (loss)		$ (153)	$ (351)	$ 525	$ (597)

[1] Net gains and losses are recorded as part of "Net gain/loss from fair value adjustments" in the Consolidated Statements of Income.