XML 83 R73.htm IDEA: XBRL DOCUMENT v3.23.3

Fair Value (Details Textual) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assets liabilities transfers amount between level 1 and level 2	$ 0	$ 0
Collateral Dependent Loans
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Collateral dependent loans, unpaid principal balance with allowance recorded	5,700	1,600
Collateral dependent loans, allowance	$ 1,700	$ 372

X

- Definition

Collateral financing receivable related allowance.

+ References

No definition available.

+ Details

Name:	fmnb_CollateralFinancingReceivableRelatedAllowance
Namespace Prefix:	fmnb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Collateral financing receivable with related allowance unpaid principal balance.

+ References

No definition available.

+ Details

Name:	fmnb_CollateralFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
Namespace Prefix:	fmnb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Fair value assets liabilities level 1 and level 2 transfers amount.

+ References

No definition available.

+ Details

Name:	fmnb_FairValueAssetsAndLiabilitiesLevel1AndLevel2TransfersAmount
Namespace Prefix:	fmnb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-3

+ Details

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

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=fmnb_CollateralDependentLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: