Document and Entity Information - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Mar. 07, 2016 |
Jun. 30, 2015 |
|
| Document And Entity Information [Abstract] | |||
| Entity Registrant Name | FARMERS NATIONAL BANC CORP /OH/ | ||
| Entity Central Index Key | 0000709337 | ||
| Document Type | 10-K | ||
| Trading Symbol | FMNB | ||
| Document Period End Date | Dec. 31, 2015 | ||
| Amendment Flag | false | ||
| Document Fiscal Year Focus | 2015 | ||
| Document Fiscal Period Focus | FY | ||
| Current Fiscal Year End Date | --12-31 | ||
| Entity Well-known Seasoned Issuer | No | ||
| Entity Voluntary Filers | No | ||
| Entity Current Reporting Status | Yes | ||
| Entity Filer Category | Accelerated Filer | ||
| Entity Public Float | $ 211.8 | ||
| Entity Common Stock, Shares Outstanding | 26,935,484 |