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		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Net gain (loss)	[1]	$ 662	$ (673)	$ 2,392	$ (506)
Not Designated as Hedging Instrument [Member]
Net gain (loss)		438	(493)	1,714	(260)
Designated as Hedging Instrument [Member] | Fair Value Hedging [Member]
Net gain (loss)		$ 224	$ (180)	$ 678	$ (246)

[1] Net gains (losses) are recorded as "Net loss from fair value adjustments" in the Consolidated Statements of Income.