XML 75 R60.htm IDEA: XBRL DOCUMENT v3.8.0.1

Troubled Debt Restructurings (Details Textual)	3 Months Ended		9 Months Ended	12 Months Ended
	Mar. 31, 2018 USD ($) Loans	Mar. 31, 2017 USD ($) Loans	Sep. 30, 2017	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Financing Receivable Modifications [Line Items]
Total troubled debt restructurings	$ 5,300,000				$ 5,000,000
Specific reserves to customers	210,000				162,000
Commitments to lend additional amounts to borrowers classified as troubled debt restructurings	0				0
Provision for loan losses	$ 775,000	$ 1,050,000
Troubled debt restructured loans with subsequent payment defaults | Loans | Loans		0
Residential real estate loan
Financing Receivable Modifications [Line Items]
Troubled debt restructured loans with subsequent payment defaults | Loans | Loans	3
Loans default payment past due period	30 days
Residential Real Estate Loan And Home Equity Line Of Credit
Financing Receivable Modifications [Line Items]
Loans default payment past due period			30 days
Scenario, Forecast
Financing Receivable Modifications [Line Items]
Provision for loan losses				$ 0
Troubled debt restructurings
Financing Receivable Modifications [Line Items]
Specific reserves to customers	$ 75,000				$ 68,000
Allowance adjustment charge offs	19,000	$ 13,000
Provision for loan losses	$ 19,000	$ 13,000
Contractual Interest Rate Reduction
Financing Receivable Modifications [Line Items]
Reduction of the notes stated interest rate	1.75%	1.89%
Extended Maturity
Financing Receivable Modifications [Line Items]
Maturity period loans	6 months
Extended Maturity | Minimum
Financing Receivable Modifications [Line Items]
Maturity period loans		6 years
Extended Maturity | Maximum
Financing Receivable Modifications [Line Items]
Maturity period loans		132 months

X

- Definition

Debt instrument interest rate reduction percentage.

+ References

No definition available.

+ Details

Name:	fmnb_DebtInstrumentInterestRateReductionPercentage
Namespace Prefix:	fmnb_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Debt instrument maturity date length of extension period.

+ References

No definition available.

+ Details

Name:	fmnb_DebtInstrumentMaturityDateLengthOfExtensionPeriod
Namespace Prefix:	fmnb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Financing receivable period of modified contractually past due loans to be considered as payment default.

+ References

No definition available.

+ Details

Name:	fmnb_FinancingReceivablePeriodOfModifiedContractuallyPastDueLoansToBeConsideredAsPaymentDefault
Namespace Prefix:	fmnb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Provision (reversal) for loan losses expensed.

+ References

No definition available.

+ Details

Name:	fmnb_ProvisionReversalForLoanLossesExpensed
Namespace Prefix:	fmnb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_FinancingReceivableModificationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554

+ Details

Name:	us-gaap_FinancingReceivableModificationsRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953682-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Reflects the amount of the write-down related to a troubled debt restructuring.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554

+ Details

Name:	us-gaap_FinancingReceivablesImpairedTroubledDebtRestructuringWriteDown
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Reflects the unfunded portion of contractual agreements to lend funds to borrowers for loans whose terms have been modified by troubled debt restructuring.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18794-111554

+ Details

Name:	us-gaap_LoansAndLeasesReceivableImpairedCommitmentToLend
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_ResidentialMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=fmnb_ResidentialRealEstateLoanAndHomeEquityLineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementScenarioAxis=us-gaap_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=fmnb_TroubledDebtRestructuringsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_ContractualInterestRateReductionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_ExtendedMaturityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: