Note 11 - Long-term Borrowings - Junior Subordinated Debt Outstanding Payables (Details) - USD ($) $ in Thousands		12 Months Ended
	Apr. 07, 2006	Dec. 31, 2022	Dec. 31, 2021
Principal amount	$ 20,600	$ 28,334	$ 28,232
Junior Subordinated Debt [Member] | AMNB Statutory Trust I [Member]
Principal amount		20,619	20,619
Junior Subordinated Debt [Member] | MidCarolina Trust I [Member]
Principal amount		4,601	4,545
Junior Subordinated Debt [Member] | MidCarolina Trust II [Member]
Principal amount		$ 3,114	$ 3,068
London Interbank Offered Rate (LIBOR) [Member] | Junior Subordinated Debt [Member] | AMNB Statutory Trust I [Member]
Interest rate	1.35%	1.35%
London Interbank Offered Rate (LIBOR) [Member] | Junior Subordinated Debt [Member] | MidCarolina Trust I [Member]
Interest rate		3.45%
London Interbank Offered Rate (LIBOR) [Member] | Junior Subordinated Debt [Member] | MidCarolina Trust II [Member]
Interest rate		2.95%