Note 4 - Loans (Details Textual) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Financing Receivable, Unamortized Loan Cost (Fee)	$ 861,000		$ 181,000
Financing Receivable, Accrued Interest, after Allowance for Credit Loss	8,220		$ 7,330
Financing Receivable, Nonaccrual, Interest Income	67,000	$ 1,000
Financing Receivable, Accrued Interest, Writeoff	$ 36,000	$ 0
Financing Receivable, Nonaccrual to Outstanding, Percent	0.17%		0.00%
Financing Receivable, Allowance for Credit Loss to Outstanding, Percent	0.69%		0.61%
Mortgage Loans in Process of Foreclosure, Amount	$ 54,000		$ 0
Federal Home Loan Mortgage Corporation and Other Investors [Member]
Unpaid Principal Balance Of Loans Serviced For Others	$ 335,100		$ 391,800
Commercial and Industrial Portfolio Segment [Member] \| Minimum [Member]
Loans and Leases Receivable, Term (Year)	1 year
Commercial and Industrial Portfolio Segment [Member] \| Maximum [Member]
Loans and Leases Receivable, Term (Year)	10 years
Commercial Real Estate Portfolio Segment [Member] \| Minimum [Member]
Loans and Leases Receivable, Term (Year)	5 years
Financing Receivable, Periodic Payment Terms, Balloon Payment Period (Year)	1 year
Financing Receivable, Variable Rates Of Interest, Adjustment Period (Year)	1 year
Loan And Lease Receivable, Ratio Of Loan To Appraised Value	0.75
Commercial Real Estate Portfolio Segment [Member] \| Maximum [Member]
Loans and Leases Receivable, Term (Year)	25 years
Financing Receivable, Periodic Payment Terms, Balloon Payment Period (Year)	10 years
Financing Receivable, Variable Rates Of Interest, Adjustment Period (Year)	10 years
Loan And Lease Receivable, Ratio Of Loan To Appraised Value	0.85
Residential Portfolio Segment [Member] \| Home Equity Line-of-credit loans [Member]
Financing Receivable, Amortization Period (Year)	5 years
Residential Portfolio Segment [Member] \| Minimum [Member]
Financing Receivable, Variable Rates Of Interest, Adjustment Period (Year)	1 year
Loan And Lease Receivable, Ratio Of Loan To Appraised Value	0.80
Financing Receivable, Amortization Period (Year)	5 years
Residential Portfolio Segment [Member] \| Maximum [Member]
Financing Receivable, Variable Rates Of Interest, Adjustment Period (Year)	15 years
Financing Receivable, Amortization Period (Year)	30 years

The amortization period for the financing receivable

No definition available.

Name:	lcnb_FinancingReceivableAmortizationPeriod
Namespace Prefix:	lcnb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

The duration of the balloon payment for financing receivable.

+ References

No definition available.

+ Details

Name:	lcnb_FinancingReceivablePeriodicPaymentTermsBalloonPaymentPeriod
Namespace Prefix:	lcnb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

The duration on the adjustment period for he variable rates of interest

+ References

No definition available.

+ Details

Name:	lcnb_FinancingReceivableVariableRatesOfInterestAdjustmentPeriod
Namespace Prefix:	lcnb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

The ratio of the loan to appraised value

+ References

No definition available.

+ Details

Name:	lcnb_LoanAndLeaseReceivableRatioOfLoanToAppraisedValue
Namespace Prefix:	lcnb_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

The term length for the loans and leases receivable

+ References

No definition available.

+ Details

Name:	lcnb_LoansAndLeasesReceivableTerm
Namespace Prefix:	lcnb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

The unpaid principle balance of loans serviced for others

+ References

No definition available.

+ Details

Name:	lcnb_UnpaidPrincipalBalanceOfLoansServicedForOthers
Namespace Prefix:	lcnb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage of allowance for credit loss to total financing receivable outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph a
-Subparagraph (1)
-Publisher SEC

+ Details

Name:	srt_FinancingReceivableAllowanceForCreditLossToOutstandingPercent
Namespace Prefix:	srt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of nonaccrual to total financing receivable outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph a
-Subparagraph (2)
-Publisher SEC

+ Details

Name:	srt_FinancingReceivableNonaccrualToOutstandingPercent
Namespace Prefix:	srt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount, after allowance for credit loss, of accrued interest on financing receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-5

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-3A

+ Details

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

- Definition

Amount of writeoff of accrued interest on financing receivable recognized by reversing interest income.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3D
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-3D

+ Details

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

- Definition

Amount of interest income on financing receivable on nonaccrual status.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

+ Details

Name:	us-gaap_FinancingReceivableNonaccrualInterestIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of unamortized loan commitment, origination, and other costs (fees) on financing receivable recognized as adjustment to yield. Excludes financing receivable covered under loss sharing agreement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481598/310-20-45-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-4

Reference 3: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-SubTopic 20
-Topic 310
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481569/310-20-50-3

+ Details

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

- Definition

Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 35
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-35

+ Details

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

- Details

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

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=lcnb_CommercialAndIndustrialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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