Segment disclosures

Company overview

FARMERS NATIONAL BANC CORP /OH/

Each reported dimension combination stays separate. Revenue and operating income are shown as reported, with their dates and sources.

Revenue · Reported segment facts

59 dimension combinations 783 retained observations 24 reported periods Partial retained history

Counts describe retained dimensioned rows only. Periods and members can change across reports, and this view does not infer missing values or expected segment totals.

Operating Segments · Debit Card And Electronic Funds Transfer Fees · Bank Segment

Consolidation Items · Product Or Service · Statement Business Segments

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;srt:ProductOrServiceAxis=fmnb:DebitCardAndElectronicFundsTransferFeesMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember
PeriodValueUnitFiledEvidence
2023-04-01 – 2023-06-301810000 USD20230808Open filing evidence
2022-07-01 – 2022-09-301463000 USD20231108Open filing evidence
2022-01-01 – 2022-09-304407000 USD20231108Open filing evidence
2022-01-01 – 2022-06-302944000 USD20230808Open filing evidence
2022-01-01 – 2022-03-311416000 USD20230505Open filing evidence
2021-01-01 – 2021-12-315144000 USD20230309Open filing evidence
2021-04-01 – 2021-06-301322000 USD20220804Open filing evidence
2021-01-01 – 2021-06-302493000 USD20220804Open filing evidence
2020-01-01 – 2020-12-314264000 USD20230309Open filing evidence

Operating Segments · Debit Card And Electronic Funds Transfer Fees · Trust Segment

Consolidation Items · Product Or Service · Statement Business Segments

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;srt:ProductOrServiceAxis=fmnb:DebitCardAndElectronicFundsTransferFeesMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember
PeriodValueUnitFiledEvidence
2023-07-01 – 2023-09-300 USD20231108Open filing evidence
2023-01-01 – 2023-09-300 USD20231108Open filing evidence
2023-04-01 – 2023-06-300 USD20230808Open filing evidence
2023-01-01 – 2023-06-300 USD20230808Open filing evidence
2023-01-01 – 2023-03-310 USD20230505Open filing evidence
2022-01-01 – 2022-12-310 USD20230309Open filing evidence
2022-07-01 – 2022-09-300 USD20231108Open filing evidence
2022-01-01 – 2022-09-300 USD20231108Open filing evidence
2022-04-01 – 2022-06-300 USD20230808Open filing evidence
2022-01-01 – 2022-06-300 USD20230808Open filing evidence
2022-01-01 – 2022-03-310 USD20230505Open filing evidence
2021-01-01 – 2021-12-310 USD20230309Open filing evidence
2021-07-01 – 2021-09-300 USD20221108Open filing evidence
2021-01-01 – 2021-09-300 USD20221108Open filing evidence
2021-04-01 – 2021-06-300 USD20220804Open filing evidence
2021-01-01 – 2021-06-300 USD20220804Open filing evidence
2020-01-01 – 2020-12-310 USD20230309Open filing evidence

Operating Segments · Insurance Agency Commissions · Trust Segment

Consolidation Items · Product Or Service · Statement Business Segments

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;srt:ProductOrServiceAxis=fmnb:InsuranceAgencyCommissionsMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-03-310 USD20240509Open filing evidence
2023-01-01 – 2023-12-310 USD20240307Open filing evidence
2023-07-01 – 2023-09-300 USD20231108Open filing evidence
2023-01-01 – 2023-09-300 USD20231108Open filing evidence
2023-04-01 – 2023-06-300 USD20230808Open filing evidence
2023-01-01 – 2023-06-300 USD20230808Open filing evidence
2023-01-01 – 2023-03-310 USD20240509Open filing evidence
2022-01-01 – 2022-12-310 USD20240307Open filing evidence
2022-07-01 – 2022-09-300 USD20231108Open filing evidence
2022-01-01 – 2022-09-300 USD20231108Open filing evidence
2022-04-01 – 2022-06-300 USD20230808Open filing evidence
2022-01-01 – 2022-06-300 USD20230808Open filing evidence
2022-01-01 – 2022-03-310 USD20230505Open filing evidence
2021-01-01 – 2021-12-310 USD20240307Open filing evidence
2021-07-01 – 2021-09-300 USD20221108Open filing evidence
2021-01-01 – 2021-09-300 USD20221108Open filing evidence
2021-04-01 – 2021-06-300 USD20220804Open filing evidence
2021-01-01 – 2021-06-300 USD20220804Open filing evidence
2020-01-01 – 2020-12-310 USD20230309Open filing evidence

Operating Segments · Investment Commissions · Trust Segment

Consolidation Items · Product Or Service · Statement Business Segments

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;srt:ProductOrServiceAxis=fmnb:InvestmentCommissionsMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember
PeriodValueUnitFiledEvidence
2023-07-01 – 2023-09-300 USD20231108Open filing evidence
2023-01-01 – 2023-09-300 USD20231108Open filing evidence
2023-04-01 – 2023-06-300 USD20230808Open filing evidence
2023-01-01 – 2023-06-300 USD20230808Open filing evidence
2023-01-01 – 2023-03-310 USD20230505Open filing evidence
2022-01-01 – 2022-12-310 USD20230309Open filing evidence
2022-07-01 – 2022-09-300 USD20231108Open filing evidence
2022-01-01 – 2022-09-300 USD20231108Open filing evidence
2022-04-01 – 2022-06-300 USD20230808Open filing evidence
2022-01-01 – 2022-06-300 USD20230808Open filing evidence
2022-01-01 – 2022-03-310 USD20230505Open filing evidence
2021-01-01 – 2021-12-310 USD20230309Open filing evidence
2021-07-01 – 2021-09-300 USD20221108Open filing evidence
2021-01-01 – 2021-09-300 USD20221108Open filing evidence
2021-04-01 – 2021-06-300 USD20220804Open filing evidence
2021-01-01 – 2021-06-300 USD20220804Open filing evidence
2020-01-01 – 2020-12-310 USD20230309Open filing evidence

Operating Segments · Retirement Plan Consulting Fees · Trust Segment

Consolidation Items · Product Or Service · Statement Business Segments

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;srt:ProductOrServiceAxis=fmnb:RetirementPlanConsultingFeesMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-03-31334000 USD20240509Open filing evidence
2023-01-01 – 2023-12-311406000 USD20240307Open filing evidence
2023-07-01 – 2023-09-30360000 USD20231108Open filing evidence
2023-01-01 – 2023-09-301049000 USD20231108Open filing evidence
2023-04-01 – 2023-06-30382000 USD20230808Open filing evidence
2023-01-01 – 2023-06-30689000 USD20230808Open filing evidence
2023-01-01 – 2023-03-31307000 USD20240509Open filing evidence
2022-01-01 – 2022-12-311389000 USD20240307Open filing evidence
2022-07-01 – 2022-09-30332000 USD20231108Open filing evidence
2022-01-01 – 2022-09-301052000 USD20231108Open filing evidence
2022-04-01 – 2022-06-30323000 USD20230808Open filing evidence
2022-01-01 – 2022-06-30720000 USD20230808Open filing evidence
2022-01-01 – 2022-03-31397000 USD20230505Open filing evidence
2021-01-01 – 2021-12-311421000 USD20240307Open filing evidence
2021-07-01 – 2021-09-30334000 USD20221108Open filing evidence
2021-01-01 – 2021-09-301043000 USD20221108Open filing evidence
2021-04-01 – 2021-06-30389000 USD20220804Open filing evidence
2021-01-01 – 2021-06-30709000 USD20220804Open filing evidence
2020-01-01 – 2020-12-311523000 USD20230309Open filing evidence

Operating Segments · Retirement Plan Consulting · Bank Segment

Consolidation Items · Product Or Service · Statement Business Segments

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;srt:ProductOrServiceAxis=fmnb:RetirementPlanConsultingMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember
PeriodValueUnitFiledEvidence
2026-04-01 – 2026-06-300 USD20260806Open filing evidence
2026-01-01 – 2026-06-300 USD20260806Open filing evidence
2026-01-01 – 2026-03-310 USD20260507Open filing evidence
2025-01-01 – 2025-12-310 USD20260305Open filing evidence
2025-07-01 – 2025-09-300 USD20251106Open filing evidence
2025-01-01 – 2025-09-300 USD20251106Open filing evidence
2025-04-01 – 2025-06-300 USD20260806Open filing evidence
2025-01-01 – 2025-06-300 USD20260806Open filing evidence
2025-01-01 – 2025-03-310 USD20260507Open filing evidence
2024-01-01 – 2024-12-310 USD20260305Open filing evidence
2024-07-01 – 2024-09-300 USD20251106Open filing evidence
2024-01-01 – 2024-09-300 USD20251106Open filing evidence
2024-04-01 – 2024-06-300 USD20250807Open filing evidence
2024-01-01 – 2024-06-300 USD20250807Open filing evidence
2024-01-01 – 2024-03-310 USD20250508Open filing evidence
2023-01-01 – 2023-12-310 USD20260305Open filing evidence

Operating Segments · Retirement Plan Consulting · Trust Segment

Consolidation Items · Product Or Service · Statement Business Segments

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;srt:ProductOrServiceAxis=fmnb:RetirementPlanConsultingMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember
PeriodValueUnitFiledEvidence
2026-04-01 – 2026-06-30954000 USD20260806Open filing evidence
2026-01-01 – 2026-06-301840000 USD20260806Open filing evidence
2026-01-01 – 2026-03-31886000 USD20260507Open filing evidence
2025-01-01 – 2025-12-313650000 USD20260305Open filing evidence
2025-07-01 – 2025-09-301060000 USD20251106Open filing evidence
2025-01-01 – 2025-09-302641000 USD20251106Open filing evidence
2025-04-01 – 2025-06-30783000 USD20260806Open filing evidence
2025-01-01 – 2025-06-301581000 USD20260806Open filing evidence
2025-01-01 – 2025-03-31798000 USD20260507Open filing evidence
2024-01-01 – 2024-12-312637000 USD20260305Open filing evidence
2024-07-01 – 2024-09-30677000 USD20251106Open filing evidence
2024-01-01 – 2024-09-301918000 USD20251106Open filing evidence
2024-04-01 – 2024-06-30623000 USD20250807Open filing evidence
2024-01-01 – 2024-06-301241000 USD20250807Open filing evidence
2024-01-01 – 2024-03-31617000 USD20250508Open filing evidence
2023-01-01 – 2023-12-312467000 USD20260305Open filing evidence

Operating Segments · Deposit Account · Bank Segment

Consolidation Items · Product Or Service · Statement Business Segments

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;srt:ProductOrServiceAxis=us-gaap:DepositAccountMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember
PeriodValueUnitFiledEvidence
2023-07-01 – 2023-09-301712000 USD20231108Open filing evidence
2023-01-01 – 2023-09-304646000 USD20231108Open filing evidence
2023-04-01 – 2023-06-301501000 USD20230808Open filing evidence
2023-01-01 – 2023-06-302933000 USD20230808Open filing evidence
2023-01-01 – 2023-03-311432000 USD20230505Open filing evidence
2022-01-01 – 2022-12-314716000 USD20230309Open filing evidence
2022-07-01 – 2022-09-301229000 USD20231108Open filing evidence
2022-01-01 – 2022-09-303513000 USD20231108Open filing evidence
2022-04-01 – 2022-06-301139000 USD20230808Open filing evidence
2022-01-01 – 2022-06-302284000 USD20230808Open filing evidence
2022-01-01 – 2022-03-311145000 USD20230505Open filing evidence
2021-01-01 – 2021-12-313660000 USD20230309Open filing evidence
2021-07-01 – 2021-09-30924000 USD20221108Open filing evidence
2021-01-01 – 2021-09-302522000 USD20221108Open filing evidence
2021-04-01 – 2021-06-30790000 USD20220804Open filing evidence
2021-01-01 – 2021-06-301598000 USD20220804Open filing evidence
2020-01-01 – 2020-12-313682000 USD20230309Open filing evidence

Operating Segments · Deposit Account · Trust Segment

Consolidation Items · Product Or Service · Statement Business Segments

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;srt:ProductOrServiceAxis=us-gaap:DepositAccountMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-03-310 USD20240509Open filing evidence
2023-01-01 – 2023-12-310 USD20240307Open filing evidence
2023-07-01 – 2023-09-300 USD20231108Open filing evidence
2023-01-01 – 2023-09-300 USD20231108Open filing evidence
2023-04-01 – 2023-06-300 USD20230808Open filing evidence
2023-01-01 – 2023-06-300 USD20230808Open filing evidence
2023-01-01 – 2023-03-310 USD20240509Open filing evidence
2022-01-01 – 2022-12-310 USD20240307Open filing evidence
2022-07-01 – 2022-09-300 USD20231108Open filing evidence
2022-01-01 – 2022-09-300 USD20231108Open filing evidence
2022-04-01 – 2022-06-300 USD20230808Open filing evidence
2022-01-01 – 2022-06-300 USD20230808Open filing evidence
2022-01-01 – 2022-03-310 USD20230505Open filing evidence
2021-01-01 – 2021-12-310 USD20240307Open filing evidence
2021-07-01 – 2021-09-300 USD20221108Open filing evidence
2021-01-01 – 2021-09-300 USD20221108Open filing evidence
2021-04-01 – 2021-06-300 USD20220804Open filing evidence
2021-01-01 – 2021-06-300 USD20220804Open filing evidence
2020-01-01 – 2020-12-310 USD20230309Open filing evidence

Operating Segments · Fiduciary And Trust · Bank Segment

Consolidation Items · Product Or Service · Statement Business Segments

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;srt:ProductOrServiceAxis=us-gaap:FiduciaryAndTrustMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember
PeriodValueUnitFiledEvidence
2026-04-01 – 2026-06-300 USD20260806Open filing evidence
2026-01-01 – 2026-06-300 USD20260806Open filing evidence
2026-01-01 – 2026-03-310 USD20260507Open filing evidence
2025-01-01 – 2025-12-310 USD20260305Open filing evidence
2025-07-01 – 2025-09-300 USD20251106Open filing evidence
2025-01-01 – 2025-09-300 USD20251106Open filing evidence
2025-04-01 – 2025-06-300 USD20260806Open filing evidence
2025-01-01 – 2025-06-300 USD20260806Open filing evidence
2025-01-01 – 2025-03-310 USD20260507Open filing evidence
2024-01-01 – 2024-12-310 USD20260305Open filing evidence
2024-07-01 – 2024-09-300 USD20251106Open filing evidence
2024-01-01 – 2024-09-300 USD20251106Open filing evidence
2024-04-01 – 2024-06-300 USD20250807Open filing evidence
2024-01-01 – 2024-06-300 USD20250807Open filing evidence
2024-01-01 – 2024-03-310 USD20250508Open filing evidence
2023-01-01 – 2023-12-310 USD20260305Open filing evidence
2023-07-01 – 2023-09-300 USD20231108Open filing evidence
2023-01-01 – 2023-09-300 USD20231108Open filing evidence
2023-04-01 – 2023-06-300 USD20230808Open filing evidence
2022-01-01 – 2022-12-310 USD20230309Open filing evidence
2022-07-01 – 2022-09-300 USD20221108Open filing evidence
2022-01-01 – 2022-09-300 USD20221108Open filing evidence
2022-04-01 – 2022-06-300 USD20230808Open filing evidence
2022-01-01 – 2022-06-300 USD20230808Open filing evidence
2021-01-01 – 2021-09-300 USD20221108Open filing evidence
2021-01-01 – 2021-06-300 USD20220804Open filing evidence
2020-01-01 – 2020-12-310 USD20230309Open filing evidence

Operating Segments · Fiduciary And Trust · Trust Segment

Consolidation Items · Product Or Service · Statement Business Segments

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;srt:ProductOrServiceAxis=us-gaap:FiduciaryAndTrustMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember
PeriodValueUnitFiledEvidence
2026-04-01 – 2026-06-303089000 USD20260806Open filing evidence
2026-01-01 – 2026-06-306119000 USD20260806Open filing evidence
2026-01-01 – 2026-03-313030000 USD20260507Open filing evidence
2025-01-01 – 2025-12-3111061000 USD20260305Open filing evidence
2025-07-01 – 2025-09-302745000 USD20251106Open filing evidence
2025-01-01 – 2025-09-307982000 USD20251106Open filing evidence
2025-04-01 – 2025-06-302596000 USD20260806Open filing evidence
2025-01-01 – 2025-06-305237000 USD20260806Open filing evidence
2025-01-01 – 2025-03-312641000 USD20260507Open filing evidence
2024-01-01 – 2024-12-3110099000 USD20260305Open filing evidence
2024-07-01 – 2024-09-302544000 USD20251106Open filing evidence
2024-01-01 – 2024-09-307398000 USD20251106Open filing evidence
2024-04-01 – 2024-06-302345000 USD20250807Open filing evidence
2024-01-01 – 2024-06-304854000 USD20250807Open filing evidence
2024-01-01 – 2024-03-312510000 USD20250508Open filing evidence
2023-01-01 – 2023-12-319047000 USD20260305Open filing evidence
2023-07-01 – 2023-09-302617000 USD20231108Open filing evidence
2023-01-01 – 2023-09-307453000 USD20231108Open filing evidence
2023-04-01 – 2023-06-302248000 USD20230808Open filing evidence
2023-01-01 – 2023-06-304835000 USD20230808Open filing evidence
2023-01-01 – 2023-03-312587000 USD20230505Open filing evidence
2022-01-01 – 2022-12-319638000 USD20230309Open filing evidence
2022-07-01 – 2022-09-302370000 USD20231108Open filing evidence
2022-01-01 – 2022-09-307265000 USD20231108Open filing evidence
2022-04-01 – 2022-06-302376000 USD20230808Open filing evidence
2022-01-01 – 2022-06-304895000 USD20230808Open filing evidence
2022-01-01 – 2022-03-312519000 USD20230505Open filing evidence
2021-01-01 – 2021-12-319438000 USD20230309Open filing evidence
2021-07-01 – 2021-09-302335000 USD20221108Open filing evidence
2021-01-01 – 2021-09-306930000 USD20221108Open filing evidence
2021-04-01 – 2021-06-302358000 USD20220804Open filing evidence
2021-01-01 – 2021-06-304594000 USD20220804Open filing evidence
2020-01-01 – 2020-12-317632000 USD20230309Open filing evidence

Operating Segments · Bank Segment

Consolidation Items · Statement Business Segments

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember
PeriodValueUnitFiledEvidence
2026-04-01 – 2026-06-3084493000 USD20260806Open filing evidence
2026-01-01 – 2026-06-30150146000 USD20260806Open filing evidence
2026-01-01 – 2026-03-3165653000 USD20260507Open filing evidence
2025-01-01 – 2025-12-31229940000 USD20260305Open filing evidence
2025-07-01 – 2025-09-3058412000 USD20251106Open filing evidence
2025-01-01 – 2025-09-30171413000 USD20251106Open filing evidence
2025-04-01 – 2025-06-3056779000 USD20260806Open filing evidence
2025-01-01 – 2025-06-30113001000 USD20260806Open filing evidence
2025-01-01 – 2025-03-3156221000 USD20260507Open filing evidence
2024-01-01 – 2024-12-31222385000 USD20260305Open filing evidence
2024-07-01 – 2024-09-3056164000 USD20251106Open filing evidence
2024-01-01 – 2024-09-30165918000 USD20251106Open filing evidence
2024-04-01 – 2024-06-3055735000 USD20250807Open filing evidence
2024-01-01 – 2024-06-30109755000 USD20250807Open filing evidence
2024-01-01 – 2024-03-3154018000 USD20250508Open filing evidence
2023-01-01 – 2023-12-31208677000 USD20260305Open filing evidence

Operating Segments · Bank Segment · Debit Card And Electronic Funds Transfer Fees

Consolidation Items · Statement Business Segments · Product Or Service

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember;srt:ProductOrServiceAxis=fmnb:DebitCardAndElectronicFundsTransferFeesMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-03-311567000 USD20240509Open filing evidence
2023-01-01 – 2023-12-317059000 USD20240307Open filing evidence
2023-07-01 – 2023-09-301763000 USD20231108Open filing evidence
2023-01-01 – 2023-09-305362000 USD20231108Open filing evidence
2023-01-01 – 2023-06-303599000 USD20230808Open filing evidence
2023-01-01 – 2023-03-311789000 USD20240509Open filing evidence
2022-01-01 – 2022-12-315814000 USD20240307Open filing evidence
2022-01-01 – 2022-09-304407000 USD20221108Open filing evidence
2022-04-01 – 2022-06-301528000 USD20230808Open filing evidence
2022-01-01 – 2022-06-302944000 USD20220804Open filing evidence
2021-01-01 – 2021-12-315144000 USD20240307Open filing evidence
2021-07-01 – 2021-09-301227000 USD20221108Open filing evidence
2021-01-01 – 2021-09-303720000 USD20221108Open filing evidence

Operating Segments · Bank Segment · Insurance Agency Commissions

Consolidation Items · Statement Business Segments · Product Or Service

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember;srt:ProductOrServiceAxis=fmnb:InsuranceAgencyCommissionsMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-03-311528000 USD20240509Open filing evidence
2023-01-01 – 2023-12-315444000 USD20240307Open filing evidence
2023-07-01 – 2023-09-301116000 USD20231108Open filing evidence
2023-01-01 – 2023-09-303904000 USD20231108Open filing evidence
2023-04-01 – 2023-06-301332000 USD20230808Open filing evidence
2023-01-01 – 2023-06-302788000 USD20230808Open filing evidence
2023-01-01 – 2023-03-311456000 USD20240509Open filing evidence
2022-01-01 – 2022-12-314402000 USD20240307Open filing evidence
2022-07-01 – 2022-09-301136000 USD20231108Open filing evidence
2022-01-01 – 2022-09-303269000 USD20231108Open filing evidence
2022-04-01 – 2022-06-301086000 USD20230808Open filing evidence
2022-01-01 – 2022-06-302133000 USD20230808Open filing evidence
2022-01-01 – 2022-03-311047000 USD20230505Open filing evidence
2021-01-01 – 2021-12-313456000 USD20240307Open filing evidence
2021-07-01 – 2021-09-30799000 USD20221108Open filing evidence
2021-01-01 – 2021-09-302750000 USD20221108Open filing evidence
2021-04-01 – 2021-06-30948000 USD20220804Open filing evidence
2021-01-01 – 2021-06-301951000 USD20220804Open filing evidence
2020-01-01 – 2020-12-313124000 USD20230309Open filing evidence

Operating Segments · Bank Segment · Investment Commissions

Consolidation Items · Statement Business Segments · Product Or Service

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember;srt:ProductOrServiceAxis=fmnb:InvestmentCommissionsMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-03-31432000 USD20240509Open filing evidence
2023-01-01 – 2023-12-311978000 USD20240307Open filing evidence
2023-07-01 – 2023-09-30520000 USD20231108Open filing evidence
2023-01-01 – 2023-09-301389000 USD20231108Open filing evidence
2023-04-01 – 2023-06-30476000 USD20230808Open filing evidence
2023-01-01 – 2023-06-30869000 USD20230808Open filing evidence
2023-01-01 – 2023-03-31393000 USD20240509Open filing evidence
2022-01-01 – 2022-12-312183000 USD20240307Open filing evidence
2022-07-01 – 2022-09-30424000 USD20231108Open filing evidence
2022-01-01 – 2022-09-301675000 USD20231108Open filing evidence
2022-04-01 – 2022-06-30557000 USD20230808Open filing evidence
2022-01-01 – 2022-06-301251000 USD20230808Open filing evidence
2022-01-01 – 2022-03-31694000 USD20230505Open filing evidence
2021-01-01 – 2021-12-312276000 USD20240307Open filing evidence
2021-07-01 – 2021-09-30638000 USD20221108Open filing evidence
2021-01-01 – 2021-09-301665000 USD20221108Open filing evidence
2021-04-01 – 2021-06-30523000 USD20220804Open filing evidence
2021-01-01 – 2021-06-301027000 USD20220804Open filing evidence
2020-01-01 – 2020-12-311530000 USD20230309Open filing evidence

Operating Segments · Bank Segment · Retirement Plan Consulting Fees

Consolidation Items · Statement Business Segments · Product Or Service

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember;srt:ProductOrServiceAxis=fmnb:RetirementPlanConsultingFeesMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-03-310 USD20240509Open filing evidence
2023-01-01 – 2023-12-310 USD20240307Open filing evidence
2023-07-01 – 2023-09-300 USD20231108Open filing evidence
2023-01-01 – 2023-09-300 USD20231108Open filing evidence
2023-04-01 – 2023-06-300 USD20230808Open filing evidence
2023-01-01 – 2023-06-300 USD20230808Open filing evidence
2023-01-01 – 2023-03-310 USD20240509Open filing evidence
2022-01-01 – 2022-12-310 USD20240307Open filing evidence
2022-07-01 – 2022-09-300 USD20231108Open filing evidence
2022-01-01 – 2022-09-300 USD20231108Open filing evidence
2022-04-01 – 2022-06-300 USD20230808Open filing evidence
2022-01-01 – 2022-06-300 USD20230808Open filing evidence
2022-01-01 – 2022-03-310 USD20230505Open filing evidence
2021-01-01 – 2021-12-310 USD20240307Open filing evidence
2021-07-01 – 2021-09-300 USD20221108Open filing evidence
2021-01-01 – 2021-09-300 USD20221108Open filing evidence
2021-04-01 – 2021-06-300 USD20220804Open filing evidence
2021-01-01 – 2021-06-300 USD20220804Open filing evidence
2020-01-01 – 2020-12-310 USD20230309Open filing evidence

Operating Segments · Bank Segment · Deposit Account

Consolidation Items · Statement Business Segments · Product Or Service

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember;srt:ProductOrServiceAxis=us-gaap:DepositAccountMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-03-311583000 USD20240509Open filing evidence
2023-01-01 – 2023-12-316322000 USD20240307Open filing evidence
2023-01-01 – 2023-03-311432000 USD20240509Open filing evidence
2022-01-01 – 2022-12-314716000 USD20240307Open filing evidence
2021-01-01 – 2021-12-313660000 USD20240307Open filing evidence

Operating Segments · Bank Segment · Fiduciary And Trust

Consolidation Items · Statement Business Segments · Product Or Service

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember;srt:ProductOrServiceAxis=us-gaap:FiduciaryAndTrustMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-03-310 USD20240509Open filing evidence
2023-01-01 – 2023-12-310 USD20240307Open filing evidence
2023-01-01 – 2023-06-300 USD20230808Open filing evidence
2023-01-01 – 2023-03-310 USD20240509Open filing evidence
2022-01-01 – 2022-12-310 USD20240307Open filing evidence
2022-07-01 – 2022-09-300 USD20231108Open filing evidence
2022-01-01 – 2022-09-300 USD20231108Open filing evidence
2022-01-01 – 2022-03-310 USD20230505Open filing evidence
2021-01-01 – 2021-12-310 USD20240307Open filing evidence
2021-07-01 – 2021-09-300 USD20221108Open filing evidence
2021-04-01 – 2021-06-300 USD20220804Open filing evidence

Operating Segments · Trust Segment

Consolidation Items · Statement Business Segments

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember
PeriodValueUnitFiledEvidence
2026-04-01 – 2026-06-304043000 USD20260806Open filing evidence
2026-01-01 – 2026-06-307959000 USD20260806Open filing evidence
2026-01-01 – 2026-03-313916000 USD20260507Open filing evidence
2025-01-01 – 2025-12-3114711000 USD20260305Open filing evidence
2025-07-01 – 2025-09-303805000 USD20251106Open filing evidence
2025-01-01 – 2025-09-3010623000 USD20251106Open filing evidence
2025-04-01 – 2025-06-303379000 USD20260806Open filing evidence
2025-01-01 – 2025-06-306818000 USD20260806Open filing evidence
2025-01-01 – 2025-03-313439000 USD20260507Open filing evidence
2024-01-01 – 2024-12-3112736000 USD20260305Open filing evidence
2024-07-01 – 2024-09-303221000 USD20251106Open filing evidence
2024-01-01 – 2024-09-309316000 USD20251106Open filing evidence
2024-04-01 – 2024-06-302968000 USD20250807Open filing evidence
2024-01-01 – 2024-06-306095000 USD20250807Open filing evidence
2024-01-01 – 2024-03-313127000 USD20250508Open filing evidence
2023-01-01 – 2023-12-3111514000 USD20260305Open filing evidence

Operating Segments · Trust Segment · Debit Card And Electronic Funds Transfer Fees

Consolidation Items · Statement Business Segments · Product Or Service

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember;srt:ProductOrServiceAxis=fmnb:DebitCardAndElectronicFundsTransferFeesMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-03-310 USD20240509Open filing evidence
2023-01-01 – 2023-12-310 USD20240307Open filing evidence
2023-01-01 – 2023-03-310 USD20240509Open filing evidence
2022-01-01 – 2022-12-310 USD20240307Open filing evidence
2021-01-01 – 2021-12-310 USD20240307Open filing evidence

Operating Segments · Trust Segment · Investment Commissions

Consolidation Items · Statement Business Segments · Product Or Service

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember;srt:ProductOrServiceAxis=fmnb:InvestmentCommissionsMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-03-310 USD20240509Open filing evidence
2023-01-01 – 2023-12-310 USD20240307Open filing evidence
2023-01-01 – 2023-03-310 USD20240509Open filing evidence
2022-01-01 – 2022-12-310 USD20240307Open filing evidence
2021-01-01 – 2021-12-310 USD20240307Open filing evidence

Operating Segments · Trust Segment · Fiduciary And Trust

Consolidation Items · Statement Business Segments · Product Or Service

Source dimensions srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember;srt:ProductOrServiceAxis=us-gaap:FiduciaryAndTrustMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-03-312793000 USD20240509Open filing evidence
2023-01-01 – 2023-12-3110108000 USD20240307Open filing evidence
2023-01-01 – 2023-03-312587000 USD20240509Open filing evidence
2022-01-01 – 2022-12-319638000 USD20240307Open filing evidence
2021-01-01 – 2021-12-319438000 USD20240307Open filing evidence

Insurance Agency Commissions · Bank Segment

Product Or Service · Statement Business Segments

Source dimensions srt:ProductOrServiceAxis=fmnb:InsuranceAgencyCommissionsMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember
PeriodValueUnitFiledEvidence
2026-04-01 – 2026-06-301485000 USD20260806Open filing evidence
2026-01-01 – 2026-06-303168000 USD20260806Open filing evidence
2026-01-01 – 2026-03-311683000 USD20260507Open filing evidence
2025-01-01 – 2025-12-316531000 USD20260305Open filing evidence
2025-07-01 – 2025-09-301395000 USD20251106Open filing evidence
2025-01-01 – 2025-09-304964000 USD20251106Open filing evidence
2025-04-01 – 2025-06-301828000 USD20260806Open filing evidence
2025-01-01 – 2025-06-303569000 USD20260806Open filing evidence
2025-01-01 – 2025-03-311741000 USD20260507Open filing evidence
2024-01-01 – 2024-12-315472000 USD20260305Open filing evidence
2024-07-01 – 2024-09-301416000 USD20251106Open filing evidence
2024-01-01 – 2024-09-304199000 USD20251106Open filing evidence
2024-04-01 – 2024-06-301255000 USD20250807Open filing evidence
2024-01-01 – 2024-06-302783000 USD20250807Open filing evidence
2024-01-01 – 2024-03-311528000 USD20250508Open filing evidence
2023-01-01 – 2023-12-315444000 USD20260305Open filing evidence

Insurance Agency Commissions · Trust Segment

Product Or Service · Statement Business Segments

Source dimensions srt:ProductOrServiceAxis=fmnb:InsuranceAgencyCommissionsMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember
PeriodValueUnitFiledEvidence
2026-04-01 – 2026-06-300 USD20260806Open filing evidence
2026-01-01 – 2026-06-300 USD20260806Open filing evidence
2026-01-01 – 2026-03-310 USD20260507Open filing evidence
2025-01-01 – 2025-12-310 USD20260305Open filing evidence
2025-07-01 – 2025-09-300 USD20251106Open filing evidence
2025-01-01 – 2025-09-300 USD20251106Open filing evidence
2025-04-01 – 2025-06-300 USD20260806Open filing evidence
2025-01-01 – 2025-06-300 USD20260806Open filing evidence
2025-01-01 – 2025-03-310 USD20260507Open filing evidence
2024-01-01 – 2024-12-310 USD20260305Open filing evidence
2024-07-01 – 2024-09-300 USD20251106Open filing evidence
2024-01-01 – 2024-09-300 USD20251106Open filing evidence
2024-04-01 – 2024-06-300 USD20250807Open filing evidence
2024-01-01 – 2024-06-300 USD20250807Open filing evidence
2024-01-01 – 2024-03-310 USD20250508Open filing evidence
2023-01-01 – 2023-12-310 USD20260305Open filing evidence

Investment Commissions · Bank Segment

Product Or Service · Statement Business Segments

Source dimensions srt:ProductOrServiceAxis=fmnb:InvestmentCommissionsMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember
PeriodValueUnitFiledEvidence
2026-04-01 – 2026-06-301044000 USD20260806Open filing evidence
2026-01-01 – 2026-06-301915000 USD20260806Open filing evidence
2026-01-01 – 2026-03-31871000 USD20260507Open filing evidence
2025-01-01 – 2025-12-312614000 USD20260305Open filing evidence
2025-07-01 – 2025-09-30658000 USD20251106Open filing evidence
2025-01-01 – 2025-09-301908000 USD20251106Open filing evidence
2025-04-01 – 2025-06-30721000 USD20260806Open filing evidence
2025-01-01 – 2025-06-301250000 USD20260806Open filing evidence
2025-01-01 – 2025-03-31529000 USD20260507Open filing evidence
2024-01-01 – 2024-12-312007000 USD20260305Open filing evidence
2024-07-01 – 2024-09-30476000 USD20251106Open filing evidence
2024-01-01 – 2024-09-301386000 USD20251106Open filing evidence
2024-04-01 – 2024-06-30478000 USD20250807Open filing evidence
2024-01-01 – 2024-06-30910000 USD20250807Open filing evidence
2024-01-01 – 2024-03-31432000 USD20250508Open filing evidence
2023-01-01 – 2023-12-311978000 USD20260305Open filing evidence

Investment Commissions · Trust Segment

Product Or Service · Statement Business Segments

Source dimensions srt:ProductOrServiceAxis=fmnb:InvestmentCommissionsMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember
PeriodValueUnitFiledEvidence
2026-04-01 – 2026-06-300 USD20260806Open filing evidence
2026-01-01 – 2026-06-300 USD20260806Open filing evidence
2026-01-01 – 2026-03-310 USD20260507Open filing evidence
2025-01-01 – 2025-12-310 USD20260305Open filing evidence
2025-07-01 – 2025-09-300 USD20251106Open filing evidence
2025-01-01 – 2025-09-300 USD20251106Open filing evidence
2025-04-01 – 2025-06-300 USD20260806Open filing evidence
2025-01-01 – 2025-06-300 USD20260806Open filing evidence
2025-01-01 – 2025-03-310 USD20260507Open filing evidence
2024-01-01 – 2024-12-310 USD20260305Open filing evidence
2024-07-01 – 2024-09-300 USD20251106Open filing evidence
2024-01-01 – 2024-09-300 USD20251106Open filing evidence
2024-04-01 – 2024-06-300 USD20250807Open filing evidence
2024-01-01 – 2024-06-300 USD20250807Open filing evidence
2024-01-01 – 2024-03-310 USD20250508Open filing evidence
2023-01-01 – 2023-12-310 USD20260305Open filing evidence

Retirement Plan Consulting Fees · Bank Segment · Operating Segments

Product Or Service · Statement Business Segments · Consolidation Items

Source dimensions srt:ProductOrServiceAxis=fmnb:RetirementPlanConsultingFeesMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-12-310 USD20250306Open filing evidence
2024-07-01 – 2024-09-300 USD20241107Open filing evidence
2024-01-01 – 2024-09-300 USD20241107Open filing evidence
2024-04-01 – 2024-06-300 USD20240808Open filing evidence
2024-01-01 – 2024-06-300 USD20240808Open filing evidence
2023-01-01 – 2023-12-310 USD20250306Open filing evidence
2023-07-01 – 2023-09-300 USD20241107Open filing evidence
2023-01-01 – 2023-09-300 USD20241107Open filing evidence
2023-04-01 – 2023-06-300 USD20240808Open filing evidence
2023-01-01 – 2023-06-300 USD20240808Open filing evidence
2022-01-01 – 2022-12-310 USD20250306Open filing evidence

Retirement Plan Consulting Fees · Trust Segment · Operating Segments

Product Or Service · Statement Business Segments · Consolidation Items

Source dimensions srt:ProductOrServiceAxis=fmnb:RetirementPlanConsultingFeesMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-12-312637000 USD20250306Open filing evidence
2024-07-01 – 2024-09-30677000 USD20241107Open filing evidence
2024-01-01 – 2024-09-301918000 USD20241107Open filing evidence
2024-04-01 – 2024-06-30330000 USD20240808Open filing evidence
2024-01-01 – 2024-06-30664000 USD20240808Open filing evidence
2023-01-01 – 2023-12-312467000 USD20250306Open filing evidence
2023-07-01 – 2023-09-30650000 USD20241107Open filing evidence
2023-01-01 – 2023-09-301837000 USD20241107Open filing evidence
2023-04-01 – 2023-06-30382000 USD20240808Open filing evidence
2023-01-01 – 2023-06-30689000 USD20240808Open filing evidence
2022-01-01 – 2022-12-312567000 USD20250306Open filing evidence

Retirement Plan Consulting · Bank Segment

Product Or Service · Statement Business Segments

Source dimensions srt:ProductOrServiceAxis=fmnb:RetirementPlanConsultingMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember
PeriodValueUnitFiledEvidence
2026-04-01 – 2026-06-300 USD20260806Open filing evidence
2026-01-01 – 2026-06-300 USD20260806Open filing evidence
2026-01-01 – 2026-03-310 USD20260507Open filing evidence
2025-01-01 – 2025-12-310 USD20260305Open filing evidence
2025-07-01 – 2025-09-300 USD20251106Open filing evidence
2025-01-01 – 2025-09-300 USD20251106Open filing evidence
2025-04-01 – 2025-06-300 USD20260806Open filing evidence
2025-01-01 – 2025-06-300 USD20260806Open filing evidence
2025-01-01 – 2025-03-310 USD20260507Open filing evidence
2024-01-01 – 2024-12-310 USD20260305Open filing evidence
2024-07-01 – 2024-09-300 USD20251106Open filing evidence
2024-01-01 – 2024-09-300 USD20251106Open filing evidence
2024-04-01 – 2024-06-300 USD20250807Open filing evidence
2024-01-01 – 2024-06-300 USD20250807Open filing evidence
2024-01-01 – 2024-03-310 USD20250508Open filing evidence
2023-01-01 – 2023-12-310 USD20260305Open filing evidence

Retirement Plan Consulting · Trust Segment

Product Or Service · Statement Business Segments

Source dimensions srt:ProductOrServiceAxis=fmnb:RetirementPlanConsultingMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember
PeriodValueUnitFiledEvidence
2026-04-01 – 2026-06-30954000 USD20260806Open filing evidence
2026-01-01 – 2026-06-301840000 USD20260806Open filing evidence
2026-01-01 – 2026-03-31886000 USD20260507Open filing evidence
2025-01-01 – 2025-12-313650000 USD20260305Open filing evidence
2025-07-01 – 2025-09-301060000 USD20251106Open filing evidence
2025-01-01 – 2025-09-302641000 USD20251106Open filing evidence
2025-04-01 – 2025-06-30783000 USD20260806Open filing evidence
2025-01-01 – 2025-06-301581000 USD20260806Open filing evidence
2025-01-01 – 2025-03-31798000 USD20260507Open filing evidence
2024-01-01 – 2024-12-312637000 USD20260305Open filing evidence
2024-07-01 – 2024-09-30677000 USD20251106Open filing evidence
2024-01-01 – 2024-09-301918000 USD20251106Open filing evidence
2024-04-01 – 2024-06-30623000 USD20250807Open filing evidence
2024-01-01 – 2024-06-301241000 USD20250807Open filing evidence
2024-01-01 – 2024-03-31617000 USD20250508Open filing evidence
2023-01-01 – 2023-12-312467000 USD20260305Open filing evidence

Debit Card · Bank Segment

Product Or Service · Statement Business Segments

Source dimensions srt:ProductOrServiceAxis=us-gaap:DebitCardMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember
PeriodValueUnitFiledEvidence
2026-04-01 – 2026-06-302561000 USD20260806Open filing evidence
2026-01-01 – 2026-06-304584000 USD20260806Open filing evidence
2026-01-01 – 2026-03-312023000 USD20260507Open filing evidence
2025-01-01 – 2025-12-317907000 USD20260305Open filing evidence
2025-07-01 – 2025-09-302068000 USD20251106Open filing evidence
2025-01-01 – 2025-09-305951000 USD20251106Open filing evidence
2025-04-01 – 2025-06-302017000 USD20260806Open filing evidence
2025-01-01 – 2025-06-303882000 USD20260806Open filing evidence
2025-01-01 – 2025-03-311866000 USD20260507Open filing evidence
2024-01-01 – 2024-12-317484000 USD20260305Open filing evidence
2024-07-01 – 2024-09-301993000 USD20251106Open filing evidence
2024-01-01 – 2024-09-305320000 USD20251106Open filing evidence
2024-04-01 – 2024-06-301760000 USD20250807Open filing evidence
2024-01-01 – 2024-06-303327000 USD20250807Open filing evidence
2024-01-01 – 2024-03-311567000 USD20250508Open filing evidence
2023-01-01 – 2023-12-317059000 USD20260305Open filing evidence

Debit Card · Trust Segment

Product Or Service · Statement Business Segments

Source dimensions srt:ProductOrServiceAxis=us-gaap:DebitCardMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember
PeriodValueUnitFiledEvidence
2026-04-01 – 2026-06-300 USD20260806Open filing evidence
2026-01-01 – 2026-06-300 USD20260806Open filing evidence
2026-01-01 – 2026-03-310 USD20260507Open filing evidence
2025-01-01 – 2025-12-310 USD20260305Open filing evidence
2025-07-01 – 2025-09-300 USD20251106Open filing evidence
2025-01-01 – 2025-09-300 USD20251106Open filing evidence
2025-04-01 – 2025-06-300 USD20260806Open filing evidence
2025-01-01 – 2025-06-300 USD20260806Open filing evidence
2025-01-01 – 2025-03-310 USD20260507Open filing evidence
2024-01-01 – 2024-12-310 USD20260305Open filing evidence
2024-07-01 – 2024-09-300 USD20251106Open filing evidence
2024-01-01 – 2024-09-300 USD20251106Open filing evidence
2024-04-01 – 2024-06-300 USD20250807Open filing evidence
2024-01-01 – 2024-06-300 USD20250807Open filing evidence
2024-01-01 – 2024-03-310 USD20250508Open filing evidence
2023-01-01 – 2023-12-310 USD20260305Open filing evidence

Deposit Account · Bank Segment

Product Or Service · Statement Business Segments

Source dimensions srt:ProductOrServiceAxis=us-gaap:DepositAccountMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember
PeriodValueUnitFiledEvidence
2026-04-01 – 2026-06-302434000 USD20260806Open filing evidence
2026-01-01 – 2026-06-304400000 USD20260806Open filing evidence
2026-01-01 – 2026-03-311966000 USD20260507Open filing evidence
2025-01-01 – 2025-12-317212000 USD20260305Open filing evidence
2025-07-01 – 2025-09-301874000 USD20251106Open filing evidence
2025-01-01 – 2025-09-305381000 USD20251106Open filing evidence
2025-04-01 – 2025-06-301749000 USD20260806Open filing evidence
2025-01-01 – 2025-06-303507000 USD20260806Open filing evidence
2025-01-01 – 2025-03-311758000 USD20260507Open filing evidence
2024-01-01 – 2024-12-317311000 USD20260305Open filing evidence
2024-07-01 – 2024-09-301992000 USD20251106Open filing evidence
2024-01-01 – 2024-09-305421000 USD20251106Open filing evidence
2024-04-01 – 2024-06-301846000 USD20250807Open filing evidence
2024-01-01 – 2024-06-303429000 USD20250807Open filing evidence
2024-01-01 – 2024-03-311583000 USD20250508Open filing evidence
2023-01-01 – 2023-12-316322000 USD20260305Open filing evidence

Deposit Account · Bank Segment · Operating Segments

Product Or Service · Statement Business Segments · Consolidation Items

Source dimensions srt:ProductOrServiceAxis=us-gaap:DepositAccountMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-12-317311000 USD20250306Open filing evidence
2024-07-01 – 2024-09-301992000 USD20241107Open filing evidence
2024-01-01 – 2024-09-305421000 USD20241107Open filing evidence
2024-04-01 – 2024-06-301846000 USD20240808Open filing evidence
2024-01-01 – 2024-06-303429000 USD20240808Open filing evidence
2023-01-01 – 2023-12-316322000 USD20250306Open filing evidence
2023-07-01 – 2023-09-301712000 USD20241107Open filing evidence
2023-01-01 – 2023-09-304646000 USD20241107Open filing evidence
2023-04-01 – 2023-06-301501000 USD20240808Open filing evidence
2023-01-01 – 2023-06-302933000 USD20240808Open filing evidence
2022-01-01 – 2022-12-314716000 USD20250306Open filing evidence

Deposit Account · Trust Segment

Product Or Service · Statement Business Segments

Source dimensions srt:ProductOrServiceAxis=us-gaap:DepositAccountMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember
PeriodValueUnitFiledEvidence
2026-04-01 – 2026-06-300 USD20260806Open filing evidence
2026-01-01 – 2026-06-300 USD20260806Open filing evidence
2026-01-01 – 2026-03-310 USD20260507Open filing evidence
2025-01-01 – 2025-12-310 USD20260305Open filing evidence
2025-07-01 – 2025-09-300 USD20251106Open filing evidence
2025-01-01 – 2025-09-300 USD20251106Open filing evidence
2025-04-01 – 2025-06-300 USD20260806Open filing evidence
2025-01-01 – 2025-06-300 USD20260806Open filing evidence
2025-01-01 – 2025-03-310 USD20260507Open filing evidence
2024-01-01 – 2024-12-310 USD20260305Open filing evidence
2024-07-01 – 2024-09-300 USD20251106Open filing evidence
2024-01-01 – 2024-09-300 USD20251106Open filing evidence
2024-04-01 – 2024-06-300 USD20250807Open filing evidence
2024-01-01 – 2024-06-300 USD20250807Open filing evidence
2024-01-01 – 2024-03-310 USD20250508Open filing evidence
2023-01-01 – 2023-12-310 USD20260305Open filing evidence

Deposit Account · Trust Segment · Operating Segments

Product Or Service · Statement Business Segments · Consolidation Items

Source dimensions srt:ProductOrServiceAxis=us-gaap:DepositAccountMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-12-310 USD20250306Open filing evidence
2024-07-01 – 2024-09-300 USD20241107Open filing evidence
2024-01-01 – 2024-09-300 USD20241107Open filing evidence
2024-04-01 – 2024-06-300 USD20240808Open filing evidence
2024-01-01 – 2024-06-300 USD20240808Open filing evidence
2023-01-01 – 2023-12-310 USD20250306Open filing evidence
2023-07-01 – 2023-09-300 USD20241107Open filing evidence
2023-01-01 – 2023-09-300 USD20241107Open filing evidence
2023-04-01 – 2023-06-300 USD20240808Open filing evidence
2023-01-01 – 2023-06-300 USD20240808Open filing evidence
2022-01-01 – 2022-12-310 USD20250306Open filing evidence

Fiduciary And Trust · Bank Segment

Product Or Service · Statement Business Segments

Source dimensions srt:ProductOrServiceAxis=us-gaap:FiduciaryAndTrustMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember
PeriodValueUnitFiledEvidence
2026-04-01 – 2026-06-300 USD20260806Open filing evidence
2026-01-01 – 2026-06-300 USD20260806Open filing evidence
2026-01-01 – 2026-03-310 USD20260507Open filing evidence
2025-01-01 – 2025-12-310 USD20260305Open filing evidence
2025-07-01 – 2025-09-300 USD20251106Open filing evidence
2025-01-01 – 2025-09-300 USD20251106Open filing evidence
2025-04-01 – 2025-06-300 USD20260806Open filing evidence
2025-01-01 – 2025-06-300 USD20260806Open filing evidence
2025-01-01 – 2025-03-310 USD20260507Open filing evidence
2024-01-01 – 2024-12-310 USD20260305Open filing evidence
2024-07-01 – 2024-09-300 USD20251106Open filing evidence
2024-01-01 – 2024-09-300 USD20251106Open filing evidence
2024-04-01 – 2024-06-300 USD20250807Open filing evidence
2024-01-01 – 2024-06-300 USD20250807Open filing evidence
2024-01-01 – 2024-03-310 USD20250508Open filing evidence
2023-01-01 – 2023-12-310 USD20260305Open filing evidence

Fiduciary And Trust · Trust Segment

Product Or Service · Statement Business Segments

Source dimensions srt:ProductOrServiceAxis=us-gaap:FiduciaryAndTrustMember;us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember
PeriodValueUnitFiledEvidence
2026-04-01 – 2026-06-303089000 USD20260806Open filing evidence
2026-01-01 – 2026-06-306119000 USD20260806Open filing evidence
2026-01-01 – 2026-03-313030000 USD20260507Open filing evidence
2025-01-01 – 2025-12-3111061000 USD20260305Open filing evidence
2025-07-01 – 2025-09-302745000 USD20251106Open filing evidence
2025-01-01 – 2025-09-307982000 USD20251106Open filing evidence
2025-04-01 – 2025-06-302596000 USD20260806Open filing evidence
2025-01-01 – 2025-06-305237000 USD20260806Open filing evidence
2025-01-01 – 2025-03-312641000 USD20260507Open filing evidence
2024-01-01 – 2024-12-3110099000 USD20260305Open filing evidence
2024-07-01 – 2024-09-302544000 USD20251106Open filing evidence
2024-01-01 – 2024-09-307398000 USD20251106Open filing evidence
2024-04-01 – 2024-06-302345000 USD20250807Open filing evidence
2024-01-01 – 2024-06-304854000 USD20250807Open filing evidence
2024-01-01 – 2024-03-312510000 USD20250508Open filing evidence
2023-01-01 – 2023-12-319047000 USD20260305Open filing evidence

Bank Segment · Operating Segments

Statement Business Segments · Consolidation Items

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-12-31222385000 USD20250306Open filing evidence
2023-01-01 – 2023-12-31208677000 USD20250306Open filing evidence
2022-01-01 – 2022-12-31140355000 USD20250306Open filing evidence

Bank Segment · Operating Segments · Debit Card And Electronic Funds Transfer Fees

Statement Business Segments · Consolidation Items · Product Or Service

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;srt:ProductOrServiceAxis=fmnb:DebitCardAndElectronicFundsTransferFeesMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-12-317484000 USD20250306Open filing evidence
2024-07-01 – 2024-09-301993000 USD20241107Open filing evidence
2024-01-01 – 2024-09-305320000 USD20241107Open filing evidence
2024-04-01 – 2024-06-301760000 USD20240808Open filing evidence
2024-01-01 – 2024-06-303327000 USD20240808Open filing evidence
2023-01-01 – 2023-12-317059000 USD20250306Open filing evidence
2023-07-01 – 2023-09-301763000 USD20241107Open filing evidence
2023-01-01 – 2023-09-305362000 USD20241107Open filing evidence
2023-04-01 – 2023-06-301810000 USD20240808Open filing evidence
2023-01-01 – 2023-06-303599000 USD20240808Open filing evidence
2022-01-01 – 2022-12-315814000 USD20250306Open filing evidence

Bank Segment · Operating Segments · Investment Commissions

Statement Business Segments · Consolidation Items · Product Or Service

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;srt:ProductOrServiceAxis=fmnb:InvestmentCommissionsMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-12-312007000 USD20250306Open filing evidence
2024-07-01 – 2024-09-30476000 USD20241107Open filing evidence
2024-01-01 – 2024-09-301386000 USD20241107Open filing evidence
2024-04-01 – 2024-06-30478000 USD20240808Open filing evidence
2024-01-01 – 2024-06-30910000 USD20240808Open filing evidence
2023-01-01 – 2023-12-311978000 USD20250306Open filing evidence
2023-07-01 – 2023-09-30520000 USD20241107Open filing evidence
2023-01-01 – 2023-09-301389000 USD20241107Open filing evidence
2023-04-01 – 2023-06-30476000 USD20240808Open filing evidence
2023-01-01 – 2023-06-30869000 USD20240808Open filing evidence
2022-01-01 – 2022-12-312183000 USD20250306Open filing evidence

Bank Segment · Operating Segments · Fiduciary And Trust

Statement Business Segments · Consolidation Items · Product Or Service

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;srt:ProductOrServiceAxis=us-gaap:FiduciaryAndTrustMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-12-310 USD20250306Open filing evidence
2024-07-01 – 2024-09-300 USD20241107Open filing evidence
2024-01-01 – 2024-09-300 USD20241107Open filing evidence
2024-04-01 – 2024-06-300 USD20240808Open filing evidence
2024-01-01 – 2024-06-300 USD20240808Open filing evidence
2023-01-01 – 2023-12-310 USD20250306Open filing evidence
2023-07-01 – 2023-09-300 USD20241107Open filing evidence
2023-01-01 – 2023-09-300 USD20241107Open filing evidence
2023-04-01 – 2023-06-300 USD20240808Open filing evidence
2023-01-01 – 2023-06-300 USD20240808Open filing evidence
2022-01-01 – 2022-12-310 USD20250306Open filing evidence

Bank Segment · Debit Card And Electronic Funds Transfer Fees · Operating Segments

Statement Business Segments · Product Or Service · Consolidation Items

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember;srt:ProductOrServiceAxis=fmnb:DebitCardAndElectronicFundsTransferFeesMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember
PeriodValueUnitFiledEvidence
2022-01-01 – 2022-03-311416000 USD20220505Open filing evidence
2021-01-01 – 2021-12-315144000 USD20220309Open filing evidence
2021-07-01 – 2021-09-301128000 USD20211104Open filing evidence
2021-01-01 – 2021-09-303438000 USD20211104Open filing evidence
2021-04-01 – 2021-06-301226000 USD20210805Open filing evidence
2021-01-01 – 2021-06-302310000 USD20210805Open filing evidence
2021-01-01 – 2021-03-311171000 RestatedUSD20220505Open filing evidence
2020-01-01 – 2020-12-314264000 RestatedUSD20220309Open filing evidence
2020-07-01 – 2020-09-301048000 USD20211104Open filing evidence
2020-01-01 – 2020-09-302866000 USD20211104Open filing evidence

Bank Segment · Insurance Agency Commissions · Operating Segments

Statement Business Segments · Product Or Service · Consolidation Items

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember;srt:ProductOrServiceAxis=fmnb:InsuranceAgencyCommissionsMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-12-315472000 USD20250306Open filing evidence
2024-07-01 – 2024-09-301416000 USD20241107Open filing evidence
2024-01-01 – 2024-09-304199000 USD20241107Open filing evidence
2024-04-01 – 2024-06-301255000 USD20240808Open filing evidence
2024-01-01 – 2024-06-302783000 USD20240808Open filing evidence
2023-01-01 – 2023-12-315444000 USD20250306Open filing evidence
2023-07-01 – 2023-09-301116000 USD20241107Open filing evidence
2023-01-01 – 2023-09-303904000 USD20241107Open filing evidence
2023-04-01 – 2023-06-301332000 USD20240808Open filing evidence
2023-01-01 – 2023-06-302788000 USD20240808Open filing evidence
2022-01-01 – 2022-12-314402000 USD20250306Open filing evidence
2022-01-01 – 2022-03-311047000 USD20220505Open filing evidence
2021-01-01 – 2021-12-313456000 USD20220309Open filing evidence
2021-07-01 – 2021-09-30799000 USD20211104Open filing evidence
2021-01-01 – 2021-09-302748000 USD20211104Open filing evidence
2021-04-01 – 2021-06-30948000 USD20210805Open filing evidence
2021-01-01 – 2021-06-301949000 USD20210805Open filing evidence
2021-01-01 – 2021-03-311003000 RestatedUSD20220505Open filing evidence
2020-01-01 – 2020-12-313124000 USD20220309Open filing evidence
2020-07-01 – 2020-09-30784000 USD20211104Open filing evidence
2020-01-01 – 2020-09-302348000 USD20211104Open filing evidence

Bank Segment · Investment Commissions · Operating Segments

Statement Business Segments · Product Or Service · Consolidation Items

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember;srt:ProductOrServiceAxis=fmnb:InvestmentCommissionsMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember
PeriodValueUnitFiledEvidence
2022-01-01 – 2022-03-31694000 USD20220505Open filing evidence
2021-01-01 – 2021-12-312276000 USD20220309Open filing evidence
2021-07-01 – 2021-09-30638000 USD20211104Open filing evidence
2021-01-01 – 2021-09-301665000 USD20211104Open filing evidence
2021-04-01 – 2021-06-30523000 USD20210805Open filing evidence
2021-01-01 – 2021-06-301027000 USD20210805Open filing evidence
2021-01-01 – 2021-03-31504000 USD20220505Open filing evidence
2020-01-01 – 2020-12-311530000 USD20220309Open filing evidence
2020-07-01 – 2020-09-30353000 USD20211104Open filing evidence
2020-01-01 – 2020-09-301080000 USD20211104Open filing evidence

Bank Segment · Retirement Plan Consulting Fees · Operating Segments

Statement Business Segments · Product Or Service · Consolidation Items

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember;srt:ProductOrServiceAxis=fmnb:RetirementPlanConsultingFeesMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember
PeriodValueUnitFiledEvidence
2022-01-01 – 2022-03-310 USD20220505Open filing evidence
2021-01-01 – 2021-12-310 USD20220309Open filing evidence
2021-07-01 – 2021-09-300 USD20211104Open filing evidence
2021-01-01 – 2021-09-300 USD20211104Open filing evidence
2021-04-01 – 2021-06-300 USD20210805Open filing evidence
2021-01-01 – 2021-06-300 USD20210805Open filing evidence
2021-01-01 – 2021-03-310 USD20220505Open filing evidence
2020-01-01 – 2020-12-310 USD20220309Open filing evidence
2020-07-01 – 2020-09-300 USD20211104Open filing evidence
2020-01-01 – 2020-09-300 USD20211104Open filing evidence

Bank Segment · Deposit Account · Operating Segments

Statement Business Segments · Product Or Service · Consolidation Items

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember;srt:ProductOrServiceAxis=us-gaap:DepositAccountMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember
PeriodValueUnitFiledEvidence
2022-01-01 – 2022-03-311145000 USD20220505Open filing evidence
2021-01-01 – 2021-12-313660000 USD20220309Open filing evidence
2021-07-01 – 2021-09-30924000 USD20211104Open filing evidence
2021-01-01 – 2021-09-302522000 USD20211104Open filing evidence
2021-04-01 – 2021-06-30790000 USD20210805Open filing evidence
2021-01-01 – 2021-06-301598000 USD20210805Open filing evidence
2021-01-01 – 2021-03-31808000 USD20220505Open filing evidence
2020-01-01 – 2020-12-313682000 USD20220309Open filing evidence
2020-07-01 – 2020-09-30904000 USD20211104Open filing evidence
2020-01-01 – 2020-09-302752000 USD20211104Open filing evidence

Bank Segment · Fiduciary And Trust · Operating Segments

Statement Business Segments · Product Or Service · Consolidation Items

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember;srt:ProductOrServiceAxis=us-gaap:FiduciaryAndTrustMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember
PeriodValueUnitFiledEvidence
2022-01-01 – 2022-03-310 USD20220505Open filing evidence
2021-01-01 – 2021-12-310 USD20220309Open filing evidence
2021-07-01 – 2021-09-300 USD20211104Open filing evidence
2021-01-01 – 2021-09-300 USD20211104Open filing evidence
2021-04-01 – 2021-06-300 USD20210805Open filing evidence
2021-01-01 – 2021-06-300 USD20210805Open filing evidence
2021-01-01 – 2021-03-310 USD20220505Open filing evidence
2020-01-01 – 2020-12-310 USD20220309Open filing evidence
2020-07-01 – 2020-09-300 USD20211104Open filing evidence
2020-01-01 – 2020-09-300 USD20211104Open filing evidence

Bank Segment · Financial Service Other · Operating Segments

Statement Business Segments · Product Or Service · Consolidation Items

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:BankSegmentMember;srt:ProductOrServiceAxis=us-gaap:FinancialServiceOtherMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember
PeriodValueUnitFiledEvidence
2020-07-01 – 2020-09-304064000 USD20201105Open filing evidence
2020-01-01 – 2020-09-3010616000 USD20201105Open filing evidence

Trust Segment · Operating Segments

Statement Business Segments · Consolidation Items

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-12-3112736000 USD20250306Open filing evidence
2023-01-01 – 2023-12-3111514000 USD20250306Open filing evidence
2022-01-01 – 2022-12-3111027000 USD20250306Open filing evidence

Trust Segment · Operating Segments · Debit Card And Electronic Funds Transfer Fees

Statement Business Segments · Consolidation Items · Product Or Service

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;srt:ProductOrServiceAxis=fmnb:DebitCardAndElectronicFundsTransferFeesMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-12-310 USD20250306Open filing evidence
2024-07-01 – 2024-09-300 USD20241107Open filing evidence
2024-01-01 – 2024-09-300 USD20241107Open filing evidence
2024-04-01 – 2024-06-300 USD20240808Open filing evidence
2024-01-01 – 2024-06-300 USD20240808Open filing evidence
2023-01-01 – 2023-12-310 USD20250306Open filing evidence
2023-07-01 – 2023-09-300 USD20241107Open filing evidence
2023-01-01 – 2023-09-300 USD20241107Open filing evidence
2023-04-01 – 2023-06-300 USD20240808Open filing evidence
2023-01-01 – 2023-06-300 USD20240808Open filing evidence
2022-01-01 – 2022-12-310 USD20250306Open filing evidence

Trust Segment · Operating Segments · Investment Commissions

Statement Business Segments · Consolidation Items · Product Or Service

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;srt:ProductOrServiceAxis=fmnb:InvestmentCommissionsMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-12-310 USD20250306Open filing evidence
2024-07-01 – 2024-09-300 USD20241107Open filing evidence
2024-01-01 – 2024-09-300 USD20241107Open filing evidence
2024-04-01 – 2024-06-300 USD20240808Open filing evidence
2024-01-01 – 2024-06-300 USD20240808Open filing evidence
2023-01-01 – 2023-12-310 USD20250306Open filing evidence
2023-07-01 – 2023-09-300 USD20241107Open filing evidence
2023-01-01 – 2023-09-300 USD20241107Open filing evidence
2023-04-01 – 2023-06-300 USD20240808Open filing evidence
2023-01-01 – 2023-06-300 USD20240808Open filing evidence
2022-01-01 – 2022-12-310 USD20250306Open filing evidence

Trust Segment · Operating Segments · Fiduciary And Trust

Statement Business Segments · Consolidation Items · Product Or Service

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember;srt:ProductOrServiceAxis=us-gaap:FiduciaryAndTrustMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-12-3110099000 USD20250306Open filing evidence
2024-07-01 – 2024-09-302544000 USD20241107Open filing evidence
2024-01-01 – 2024-09-307398000 USD20241107Open filing evidence
2024-04-01 – 2024-06-302638000 USD20240808Open filing evidence
2024-01-01 – 2024-06-305431000 USD20240808Open filing evidence
2023-01-01 – 2023-12-319047000 USD20250306Open filing evidence
2023-07-01 – 2023-09-302327000 USD20241107Open filing evidence
2023-01-01 – 2023-09-306665000 USD20241107Open filing evidence
2023-04-01 – 2023-06-302248000 USD20240808Open filing evidence
2023-01-01 – 2023-06-304835000 USD20240808Open filing evidence
2022-01-01 – 2022-12-318460000 USD20250306Open filing evidence

Trust Segment · Debit Card And Electronic Funds Transfer Fees · Operating Segments

Statement Business Segments · Product Or Service · Consolidation Items

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember;srt:ProductOrServiceAxis=fmnb:DebitCardAndElectronicFundsTransferFeesMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember
PeriodValueUnitFiledEvidence
2022-01-01 – 2022-03-310 USD20220505Open filing evidence
2021-01-01 – 2021-12-310 USD20220309Open filing evidence
2021-07-01 – 2021-09-300 USD20211104Open filing evidence
2021-01-01 – 2021-09-300 USD20211104Open filing evidence
2021-04-01 – 2021-06-300 USD20210805Open filing evidence
2021-01-01 – 2021-06-300 USD20210805Open filing evidence
2021-01-01 – 2021-03-310 USD20220505Open filing evidence
2020-01-01 – 2020-12-310 USD20220309Open filing evidence
2020-01-01 – 2020-09-300 USD20211104Open filing evidence

Trust Segment · Insurance Agency Commissions · Operating Segments

Statement Business Segments · Product Or Service · Consolidation Items

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember;srt:ProductOrServiceAxis=fmnb:InsuranceAgencyCommissionsMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember
PeriodValueUnitFiledEvidence
2024-01-01 – 2024-12-310 USD20250306Open filing evidence
2024-07-01 – 2024-09-300 USD20241107Open filing evidence
2024-01-01 – 2024-09-300 USD20241107Open filing evidence
2024-04-01 – 2024-06-300 USD20240808Open filing evidence
2024-01-01 – 2024-06-300 USD20240808Open filing evidence
2023-01-01 – 2023-12-310 USD20250306Open filing evidence
2023-07-01 – 2023-09-300 USD20241107Open filing evidence
2023-01-01 – 2023-09-300 USD20241107Open filing evidence
2023-04-01 – 2023-06-300 USD20240808Open filing evidence
2023-01-01 – 2023-06-300 USD20240808Open filing evidence
2022-01-01 – 2022-12-310 USD20250306Open filing evidence
2022-01-01 – 2022-03-310 USD20220505Open filing evidence
2021-01-01 – 2021-12-310 USD20220309Open filing evidence
2021-07-01 – 2021-09-300 USD20211104Open filing evidence
2021-01-01 – 2021-09-300 USD20211104Open filing evidence
2021-04-01 – 2021-06-300 USD20210805Open filing evidence
2021-01-01 – 2021-06-300 USD20210805Open filing evidence
2021-01-01 – 2021-03-310 USD20220505Open filing evidence
2020-01-01 – 2020-12-310 USD20220309Open filing evidence

Trust Segment · Investment Commissions · Operating Segments

Statement Business Segments · Product Or Service · Consolidation Items

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember;srt:ProductOrServiceAxis=fmnb:InvestmentCommissionsMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember
PeriodValueUnitFiledEvidence
2022-01-01 – 2022-03-310 USD20220505Open filing evidence
2021-01-01 – 2021-12-310 USD20220309Open filing evidence
2021-07-01 – 2021-09-300 USD20211104Open filing evidence
2021-01-01 – 2021-09-300 USD20211104Open filing evidence
2021-04-01 – 2021-06-300 USD20210805Open filing evidence
2021-01-01 – 2021-06-300 USD20210805Open filing evidence
2021-01-01 – 2021-03-310 USD20220505Open filing evidence
2020-01-01 – 2020-12-310 USD20220309Open filing evidence

Trust Segment · Retirement Plan Consulting Fees · Operating Segments

Statement Business Segments · Product Or Service · Consolidation Items

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember;srt:ProductOrServiceAxis=fmnb:RetirementPlanConsultingFeesMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember
PeriodValueUnitFiledEvidence
2022-01-01 – 2022-03-31397000 USD20220505Open filing evidence
2021-01-01 – 2021-12-311421000 USD20220309Open filing evidence
2021-07-01 – 2021-09-30334000 USD20211104Open filing evidence
2021-01-01 – 2021-09-301043000 USD20211104Open filing evidence
2021-04-01 – 2021-06-30389000 USD20210805Open filing evidence
2021-01-01 – 2021-06-30709000 USD20210805Open filing evidence
2021-01-01 – 2021-03-31320000 USD20220505Open filing evidence
2020-01-01 – 2020-12-311523000 USD20220309Open filing evidence

Trust Segment · Deposit Account · Operating Segments

Statement Business Segments · Product Or Service · Consolidation Items

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember;srt:ProductOrServiceAxis=us-gaap:DepositAccountMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember
PeriodValueUnitFiledEvidence
2022-01-01 – 2022-03-310 USD20220505Open filing evidence
2021-01-01 – 2021-12-310 USD20220309Open filing evidence
2021-07-01 – 2021-09-300 USD20211104Open filing evidence
2021-01-01 – 2021-09-300 USD20211104Open filing evidence
2021-04-01 – 2021-06-300 USD20210805Open filing evidence
2021-01-01 – 2021-06-300 USD20210805Open filing evidence
2021-01-01 – 2021-03-310 USD20220505Open filing evidence
2020-01-01 – 2020-12-310 USD20220309Open filing evidence

Trust Segment · Fiduciary And Trust · Operating Segments

Statement Business Segments · Product Or Service · Consolidation Items

Source dimensions us-gaap:StatementBusinessSegmentsAxis=fmnb:TrustSegmentMember;srt:ProductOrServiceAxis=us-gaap:FiduciaryAndTrustMember;srt:ConsolidationItemsAxis=us-gaap:OperatingSegmentsMember
PeriodValueUnitFiledEvidence
2022-01-01 – 2022-03-312519000 USD20220505Open filing evidence
2021-01-01 – 2021-12-319438000 USD20220309Open filing evidence
2021-07-01 – 2021-09-302335000 USD20211104Open filing evidence
2021-01-01 – 2021-09-306929000 USD20211104Open filing evidence
2021-04-01 – 2021-06-302358000 USD20210805Open filing evidence
2021-01-01 – 2021-06-304594000 USD20210805Open filing evidence
2021-01-01 – 2021-03-312236000 USD20220505Open filing evidence
2020-01-01 – 2020-12-317632000 USD20220309Open filing evidence