Document And Entity Information - USD ($)	12 Months Ended
Document And Entity Information - USD ($)	Dec. 31, 2023	Mar. 26, 2024	Jun. 30, 2023
Document Information [Line Items]
Entity, Registrant Name	AMERICAN NATIONAL BANKSHARES INC.
Document, Type	10-K/A
Document, Annual Report	true
Document, Period End Date	Dec. 31, 2023
Current Fiscal Year End Date	--12-31
Document, Fiscal Period Focus	FY
Document, Fiscal Year Focus	2023
Document, Transition Report	false
Entity, File Number	0-12820
Entity, Incorporation, State or Country Code	VA
Entity, Tax Identification Number	54-1284688
Entity, Address, Address Line One	628 Main Street
Entity, Address, City or Town	Danville
Entity, Address, State or Province	VA
Entity, Address, Postal Zip Code	24541
City Area Code	434
Local Phone Number	792-5111
Title of 12(b) Security	Common Stock, $1 par value
Trading Symbol	AMNB
Security Exchange Name	NASDAQ
Entity, Well-known Seasoned Issuer	No
Entity, Voluntary Filers	No
Entity, Current Reporting Status	Yes
Entity, Interactive Data, Current	Yes
Entity, Filer Category	Accelerated Filer
Entity, Small Business	false
Entity, Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document, Financial Statement Error Correction Flag	false
Entity, Shell Company	false
Entity, Public Float			$ 321,204,000
Entity, Common Stock Shares, Outstanding		10,419,679
Amendment Description	American National Bankshares Inc. (the "Company") is filing this Amendment No. 1 on Form 10-K/A (the "Form 10-K/A") to amend its Annual Report on Form 10-K for the fiscal year ended December 31, 2023 (together with the Form 10-K/A, the "Form 10-K"), filed with the Securities and Exchange Commission (the "SEC") on March 15, 2024. The purpose of this Form 10-K/A is solely to disclose the information required in Part III (Items 10, 11, 12, 13 and 14) of Form 10-K, which information was previously omitted in reliance on General Instruction G(3) to Form 10-K. Accordingly, the Company hereby amends and replaces in its entirety Part III of the Form 10-K. In addition, pursuant to the rules of the SEC, Item 15 of Part IV has been amended to include the currently dated certifications of the Company's principal executive officer and principal financial officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. New certifications of the Company's principal executive officer and principal financial officer are filed with this Form 10-K/A as Exhibits 31.3 and 31.4 hereto. Because no financial statements have been included in this Form 10-K/A and this Form 10-K/A does not contain or amend any disclosure with respect to Items 307 and 308 of Regulation S-K, paragraphs 3, 4 and 5 of the certifications have been omitted. The Company is not including a new certification under Section 906 of the Sarbanes-Oxley Act of 2002 as no financial statements are being filed with this Form 10-K/A. Except as described above, this Form 10-K/A does not amend any other information set forth in the Form 10-K, and the Company has not updated disclosures included therein to reflect any subsequent events. This Form 10-K/A should be read in conjunction with the Form 10-K and with the Company's filings with the SEC subsequent to the Form 10-K.
Amendment Flag	true
Entity, Central Index Key	0000741516

AMERICAN NATIONAL BANKSHARES INC. 10-K/A