Note 7 - Goodwill and Other Intangible Assets (Details Textual) - USD ($)	1 Months Ended	12 Months Ended			52 Months Ended
	Apr. 30, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Apr. 30, 2019	Jan. 31, 2015	Jul. 31, 2011
Finite-Lived Intangible Asset, Useful Life (Year)	120 months
Amortization of Intangible Assets, Total		$ 1,464,000	$ 1,637,000	$ 1,398,000
MidCarolina Financial Corporation [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles						$ 1,839,000	$ 6,556,000
MainStreet BancShares, Inc and HomeTown Bankshares Corporation [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	$ 8,200,000				$ 8,200,000
Finite-Lived Intangible Asset, Useful Life (Year)					120 months