Note 19 - Fair Value Measurements - Financial Assets and Liabilities Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Securities available for sale	$ 521,519	$ 608,062
US Treasury Securities [Member]
Securities available for sale	123,767	139,427
US Government-sponsored Enterprises Debt Securities [Member]
Securities available for sale	72,233	83,348
US States and Political Subdivisions Debt Securities [Member]
Securities available for sale	42,422	63,723
Corporate Debt Securities [Member]
Securities available for sale	26,333	27,471
Fair Value, Recurring [Member]
Securities available for sale	521,519	608,062
Loans held for sale	1,279	1,061
Fair Value, Recurring [Member] \| Cash Flow Hedging [Member]
Derivative - cash flow hedges		1,325
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Securities available for sale	0	0
Loans held for sale	0	0
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Cash Flow Hedging [Member]
Derivative - cash flow hedges		0
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Securities available for sale	521,519	608,062
Loans held for sale	1,279	1,061
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Cash Flow Hedging [Member]
Derivative - cash flow hedges		1,325
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Securities available for sale	0	0
Loans held for sale	0	0
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member] \| Cash Flow Hedging [Member]
Derivative - cash flow hedges		0
Fair Value, Recurring [Member] \| US Treasury Securities [Member]
Securities available for sale	123,767	139,427
Fair Value, Recurring [Member] \| US Treasury Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] \| US Treasury Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Securities available for sale	123,767	139,427
Fair Value, Recurring [Member] \| US Treasury Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] \| US Government-sponsored Enterprises Debt Securities [Member]
Securities available for sale	72,233	83,348
Fair Value, Recurring [Member] \| US Government-sponsored Enterprises Debt Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] \| US Government-sponsored Enterprises Debt Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Securities available for sale	72,233	83,348
Fair Value, Recurring [Member] \| US Government-sponsored Enterprises Debt Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] \| Collateralized Mortgage Obligations [Member]
Securities available for sale	256,764	294,093
Fair Value, Recurring [Member] \| Collateralized Mortgage Obligations [Member] \| Fair Value, Inputs, Level 1 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] \| Collateralized Mortgage Obligations [Member] \| Fair Value, Inputs, Level 2 [Member]
Securities available for sale	256,764	294,093
Fair Value, Recurring [Member] \| Collateralized Mortgage Obligations [Member] \| Fair Value, Inputs, Level 3 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] \| US States and Political Subdivisions Debt Securities [Member]
Securities available for sale	42,422	63,723
Fair Value, Recurring [Member] \| US States and Political Subdivisions Debt Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] \| US States and Political Subdivisions Debt Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Securities available for sale	42,422	63,723
Fair Value, Recurring [Member] \| US States and Political Subdivisions Debt Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] \| Corporate Debt Securities [Member]
Securities available for sale	26,333	27,471
Fair Value, Recurring [Member] \| Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Securities available for sale	0	0
Fair Value, Recurring [Member] \| Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Securities available for sale	26,333	27,471
Fair Value, Recurring [Member] \| Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Securities available for sale	$ 0	$ 0

AMERICAN NATIONAL BANKSHARES INC. 10-K