Note 5 - Goodwill and Intangible Assets - Changes in the Net Carrying Amount of Core Deposit Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Balance at beginning of period			$ 2,285
Balance at end of period	$ 2,042		2,042
Core Deposits [Member]
Balance at beginning of period	2,122	$ 2,461	2,285	$ 1,056
Core deposit intangible acquired	0	0	0	1,519
Amortization	(80)	(88)	(243)	(202)
Balance at end of period	$ 2,042	$ 2,373	$ 2,042	$ 2,373