Note 9 - 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	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Derivative expense	$ 96	$ 12
Designated as Hedging Instrument [Member]
Derivative expense	28	12
Not Designated as Hedging Instrument [Member]
Derivative expense	$ 68	$ 0