Note 2 - Sales/Mergers/Acquisitions - FHLB Advances (Details) - USD ($) $ in Thousands		6 Months Ended	12 Months Ended
	Jul. 02, 2018	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Jul. 01, 2018
Business Acquisition [Line Items]
Common stock, issued (in shares)				15,805,711	15,828,098
Common stock, outstanding (in shares)				15,805,711	15,828,098
Acquisition costs			$ 1,795
Springfield Bancshares
Business Acquisition [Line Items]
Overnight FHLB advances assumed						$ 40,000
FHLB term advances assumed						34,500
Subordinated debentures						4,700
Bank stock loan						4,800
Fair value of FHLB and other borrowings assumed						$ 84,100
Revenue of acquiree since acquisition date		$ 15,200
Earnings of acquiree since acquisition date		4,800
Payment of bank stock loan	$ 4,800
Acquisition costs		$ 391	$ 1,400