Summary of Significant Accounting Policies	6 Months Ended
Jun. 30, 2016
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTES TO UNAUDITED CONSOLIDATED FINANCIAL STATEMENTS Principles of Consolidation: Farmers National Banc Corp. (“Company”) is a one-bank holding company registered under the Bank Holding Company Act of 1956, as amended. The Company provides full banking services through its nationally chartered subsidiary, The Farmers National Bank of Canfield (“Bank”). The Bank acquired Bowers Insurance Agency, Inc. (the “Bowers Group”) and consolidated the activity of the Bowers Group with Farmers National Insurance (“Insurance”) during 2016. The Company acquired First National Bank of Orrville (“First National Bank”) a subsidiary of National Bancshares Corporation (“NBOH”) and 1^st National Community Bank (“FNCB”) a subsidiary of Tri-State 1^st Banc, Inc. (“Tri-State”) during 2015 and consolidated all activity of both acquisitions within the Bank. The consolidated financial statements also include the accounts of the Farmers National Bank of Canfield’s subsidiaries; Farmers National Insurance and Farmers of Canfield Investment Co. (“Investments”). The Company provides trust services through its subsidiary, Farmers Trust Company (“Trust”), retirement consulting services through National Associates, Inc. (“NAI”) and insurance services through the Bank’s subsidiary, Insurance. The consolidated financial statements include the accounts of the Company, the Bank and its subsidiaries, along with Trust and NAI. All significant intercompany balances and transactions have been eliminated in the consolidation. Basis of Presentation: The unaudited condensed consolidated financial statements have been prepared in conformity with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. generally accepted accounting principles (“U.S. GAAP”) for complete financial statements. The financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s 2015 Annual Report to Shareholders included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015. The interim consolidated financial statements include all adjustments (consisting of only normal recurring items) that, in the opinion of management, are necessary for a fair presentation of the financial position and results of operations for the periods presented. The results of operations for the interim periods disclosed herein are not necessarily indicative of the results that may be expected for a full year. Certain items included in the prior period financial statements were reclassified to conform to the current period presentation. There was no effect on net income or total stockholders’ equity. Estimates: The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Segments: The Company provides a broad range of financial services to individuals and companies in northeastern Ohio. Operations are managed and financial performance is primarily aggregated and reported in three lines of business, the Bank segment, the Trust segment and the Retirement Consulting segment. Comprehensive Income: Comprehensive income consists of net income and other comprehensive income. Other comprehensive income consists of unrealized gains and losses on securities available for sale and changes in the funded status of the post-retirement health plan, which are recognized as separate components of equity, net of tax effects. For all periods presented there was no change in the funded status of the post-retirement health plan. New Accounting Standards: In June 2016, the FASB issued Accounting Standards Update ("ASU") 2016-13 - Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The revised accounting guidance will remove all recognition thresholds and will require a company to recognize an allowance for credit losses for the difference between the amortized cost basis of a financial instrument and the amount of amortized cost that the company expects to collect over the instrument's contractual life. It also amends the credit loss measurement guidance for available-for-sale debt securities and beneficial interests in securitized financial assets. This new accounting guidance will be effective for interim and annual reporting periods beginning after December 15, 2019. Management is currently evaluating the impact of adopting this new accounting guidance on Company’s consolidated financial statements.

NOTES TO UNAUDITED CONSOLIDATED FINANCIAL STATEMENTS

Principles of Consolidation:

Farmers National Banc Corp. (“Company”) is a one-bank holding company registered under the Bank Holding Company Act of 1956, as amended. The Company provides full banking services through its nationally chartered subsidiary, The Farmers National Bank of Canfield (“Bank”). The Bank acquired Bowers Insurance Agency, Inc. (the “Bowers Group”) and consolidated the activity of the Bowers Group with Farmers National Insurance (“Insurance”) during 2016. The Company acquired First National Bank of Orrville (“First National Bank”) a subsidiary of National Bancshares Corporation (“NBOH”) and 1^st National Community Bank (“FNCB”) a subsidiary of Tri-State 1^st Banc, Inc. (“Tri-State”) during 2015 and consolidated all activity of both acquisitions within the Bank. The consolidated financial statements also include the accounts of the Farmers National Bank of Canfield’s subsidiaries; Farmers National Insurance and Farmers of Canfield Investment Co. (“Investments”). The Company provides trust services through its subsidiary, Farmers Trust Company (“Trust”), retirement consulting services through National Associates, Inc. (“NAI”) and insurance services through the Bank’s subsidiary, Insurance. The consolidated financial statements include the accounts of the Company, the Bank and its subsidiaries, along with Trust and NAI. All significant intercompany balances and transactions have been eliminated in the consolidation.

Basis of Presentation:

The unaudited condensed consolidated financial statements have been prepared in conformity with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. generally accepted accounting principles (“U.S. GAAP”) for complete financial statements. The financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s 2015 Annual Report to Shareholders included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015. The interim consolidated financial statements include all adjustments (consisting of only normal recurring items) that, in the opinion of management, are necessary for a fair presentation of the financial position and results of operations for the periods presented. The results of operations for the interim periods disclosed herein are not necessarily indicative of the results that may be expected for a full year. Certain items included in the prior period financial statements were reclassified to conform to the current period presentation. There was no effect on net income or total stockholders’ equity.

Estimates:

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Segments:

The Company provides a broad range of financial services to individuals and companies in northeastern Ohio. Operations are managed and financial performance is primarily aggregated and reported in three lines of business, the Bank segment, the Trust segment and the Retirement Consulting segment.

Comprehensive Income:

Comprehensive income consists of net income and other comprehensive income. Other comprehensive income consists of unrealized gains and losses on securities available for sale and changes in the funded status of the post-retirement health plan, which are recognized as separate components of equity, net of tax effects. For all periods presented there was no change in the funded status of the post-retirement health plan.

New Accounting Standards:

In June 2016, the FASB issued Accounting Standards Update ("ASU") 2016-13 - Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The revised accounting guidance will remove all recognition thresholds and will require a company to recognize an allowance for credit losses for the difference between the amortized cost basis of a financial instrument and the amount of amortized cost that the company expects to collect over the instrument's contractual life. It also amends the credit loss measurement guidance for available-for-sale debt securities and beneficial interests in securitized financial assets. This new accounting guidance will be effective for interim and annual reporting periods beginning after December 15, 2019. Management is currently evaluating the impact of adopting this new accounting guidance on Company’s consolidated financial statements.