Financing Receivable, Amortization Period

No definition available.

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

- Definition

Financing Receivable, Line of Credit Draw Period

+ References

No definition available.

+ Details

Name:	lcnb_FinancingReceivableLineOfCreditDrawPeriod
Namespace Prefix:	lcnb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Financing Receivable, Periodic Payment Terms, Balloon Payment Period

+ References

No definition available.

+ Details

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

- Definition

Financing Receivable, Variable Rates of Interest, Adjustment Period

+ References

No definition available.

+ Details

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

- Definition

Loan and Lease Receivable, Ratio of Loan to Appraised Value

+ References

No definition available.

+ Details

Name:	lcnb_LoanAndLeaseReceivableRatioOfLoanToAppraisedValue
Namespace Prefix:	lcnb_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Loans and Leases Receivable, Maturity Period

+ References

No definition available.

+ Details

Name:	lcnb_LoansandLeasesReceivableMaturityPeriod
Namespace Prefix:	lcnb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Unpaid Principal Balance Of Loans Serviced For Others

+ References

No definition available.

+ Details

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

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

- Definition

Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 35
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL49126937-111524

+ 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=us-gaap_CommercialPortfolioSegmentMember
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_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Loans, Additional Information (Details) - USD ($)	9 Months Ended
Loans, Additional Information (Details) - USD ($)	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructurings that subsequently defaulted within 12 months of the restructuring date	$ 22,000	$ 0
Mortgage loans secured by residential real estate that were in the process of foreclosure	415,000,000
Federal Home Loan Mortgage Corporation and Other Investors [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance of loans serviced for others	$ 90,784,000,000		$ 97,685,000,000
Commercial and industrial [Member] \| Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Maturity Period	1 year
Commercial and industrial [Member] \| Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Maturity Period	10 years
Commercial, secured by real estate [Member] \| Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Adjustable rate period	1 year
Amortization period	5 years
Balloon payments period	1 year
Loan to appraised value ratio	75.00%
Commercial, secured by real estate [Member] \| Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Adjustable rate period	10 years
Amortization period	25 years
Balloon payments period	10 years
Loan to appraised value ratio	85.00%
Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Home equity line of credit draw period	5 years
Residential real estate [Member] \| Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Adjustable rate period	1 year
Amortization period	5 years
Loan to appraised value ratio	80.00%
Residential real estate [Member] \| Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Adjustable rate period	10 years
Amortization period	30 years
Consumer [Member] \| Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortization period	72 months