Note 2 - Acquisitions - Preliminary Assessment of Consideration Transferred, Assets Acquired, and Liabilities Assumed (Details) - USD ($) $ in Thousands		6 Months Ended
	Apr. 01, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Cash paid in lieu of fractional shares		$ (0)	$ 27
Goodwill resulting from merger with HomeTown		85,048	$ 84,633	$ 84,002
HomeTown Bankshares Corporation [Member]
Cash paid in lieu of fractional shares	$ 27
Value of consideration	83,250
Cash and cash equivalents	26,283
Investment securities	34,876
Restricted stock	2,588
Loans	444,324
Premises and equipment	12,034
Deferred income taxes	2,960
Core deposit intangible	8,200
Other real estate owned	1,188
Bank owned life insurance	8,246
Other assets	14,244
Total assets	554,943
Deposits	483,626
Short-term FHLB advances	14,883
Long-term FHLB advances	778
Subordinated debt	7,530
Other liabilities	6,052
Total liabilities	512,869
Net assets acquired	42,074
Goodwill resulting from merger with HomeTown	41,176	$ 41,176		$ 40,130
HomeTown Bankshares Corporation [Member] | Stock Options and Restricted Stock [Member]
Common shares issued (2,361,686)	753
HomeTown Bankshares Corporation [Member] | Common Stock [Member]
Common shares issued (2,361,686)	$ 82,470