Note 3 - Loans - Accretable Yield on Acquired Impaired Loans (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		Mar. 31, 2021	Dec. 31, 2020
Balance		$ 6,513	$ 7,893
Accretion		(712)	(3,553)
Reclassification from nonaccretable difference		451	2,233
Other changes, net (1)	[1]	79	(60)
Balance		$ 6,331	$ 6,513

[1] This line item represents changes in the cash flows expected to be collected due to the impact of non-credit changes such as prepayment assumptions, changes in interest rates on variable rate acquired impaired loans, and discounted payoffs that occurred in the period.