| Cover Page - USD ($) $ in Millions | 12 Months Ended | ||
| Dec. 31, 2023 | Mar. 01, 2024 | Jun. 30, 2021 | |
| Document Information [Line Items] | |||
| Entity Registrant Name | Farmers National Banc Corp. | ||
| Entity Central Index Key | 0000709337 | ||
| Entity Current Reporting Status | Yes | ||
| Entity Interactive Data Current | Yes | ||
| Document Type | 10-K/A | ||
| Document Period End Date | Dec. 31, 2023 | ||
| Amendment Flag | true | ||
| Document Fiscal Year Focus | 2023 | ||
| Document Fiscal Period Focus | FY | ||
| Current Fiscal Year End Date | --12-31 | ||
| Title of 12(b) Security | Common Stock, No Par Value | ||
| Trading Symbol | FMNB | ||
| Security Exchange Name | NASDAQ | ||
| Entity Well-known Seasoned Issuer | No | ||
| Entity Voluntary Filers | No | ||
| Entity Filer Category | Accelerated Filer | ||
| Entity Small Business | false | ||
| Entity Emerging Growth Company | false | ||
| Entity Common Stock, Shares Outstanding | 37,545,864 | ||
| Entity Public Float | $ 402.4 | ||
| Document Annual Report | true | ||
| Document Transition Report | false | ||
| Entity Shell Company | false | ||
| Entity File Number | 001-35296 | ||
| Entity Tax Identification Number | 34-1371693 | ||
| Entity Address, Address Line One | 20 South Broad Street | ||
| Entity Address, City or Town | Canfield | ||
| Entity Address, State or Province | OH | ||
| Entity Address, Postal Zip Code | 44406 | ||
| City Area Code | 330 | ||
| Local Phone Number | 533-3341 | ||
| Entity Incorporation, State or Country Code | OH | ||
| ICFR Auditor Attestation Flag | true | ||
| Document Financial Statement Error Correction [Flag] | false | ||
| Auditor Name | Crowe LLP | ||
| Auditor Firm ID | 173 | ||
| Auditor Location | Columbus, OH | ||
| Documents Incorporated by Reference | DOCUMENTS INCORPORATED BY REFERENCE Document Part of Form 10-K into which Document is Incorporated Portions of the registrant’s definitive proxy statement for the 2024 Annual Meeting of Shareholders III | ||
| Amendment Description | Farmers National Banc Corp. (“Farmers”) hereby amends its Annual Report on Form 10-K for the fiscal year ended December 31, 2023, filed with the Securities and Exchange Commission (the “Commission”) on March 7, 2024 (the “Form 10-K”), as set forth in this Amendment No. 1 on Form 10-K/A (this “Amendment”). This Amendment is being filed solely to re-file Exhibit 23.1, “Consent of Independent Registered Public Accounting Firm” as a document filed as an exhibit to the Form 10-K, to correct a typographical error in the Exhibit 23.1 that was originally filed as an exhibit to the Form 10-K. Except as described above, no other changes are being made to the Form 10-K and this Amendment does not modify, amend, or update in any way any of the financial or other information contained in the Form 10-K. This Amendment does not reflect subsequent events occurring after the original filing date of the Form 10-K. This Amendment should be read in conjunction with Farmers’ filings with the Commission subsequent to the filing of the Form 10-K. Pursuant to Rule 12b-15 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), currently dated certifications are filed herewith as exhibits to this Amendment pursuant to Rule 13a-14(a) or 15d-14(a) of the Exchange Act under Item 15 of Part IV hereof. Because no financial statements have been included in this Amendment and this Amendment does not contain any disclosure with respect to Items 307 and 308 of Regulation S-K, paragraphs 3, 4, and 5 of the certifications have been omitted. Similarly, because no financial statements have been included in this Amendment, certifications pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 have been omitted. |
