Note 12 - Derivative Instruments and Hedging Activities - Effect of Derivative and Hedging Activity, on Consolidated Statements of Income (Details) - Interest Rate Swap [Member] - Interest and Fees on Loans [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative expense	$ 12	$ 40	$ 78
Designated as Hedging Instrument [Member]
Derivative expense	$ 12	$ 40	$ 78