Reserve for loans impairments recorded after acquisition as a result of current information and events which result in it being probable that estimated cash flows will be less than previously expected or because actual cash flows are less than cash flows previously expected. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=27045933&loc=d3e13503-111538

+ Details

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

- Definition

The recorded balance, net of any applicable reductions (for example, unamortized accretable yield and allowance for loan losses). This relates to loans not accounted for debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=27045933&loc=d3e13503-111538

+ Details

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

- References

No definition available.

+ Details

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

- Definition

A valuation allowance for financing receivables that are expected to be uncollectible.

+ 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 (c)(1)
-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953423-111524

+ Details

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

- Definition

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively 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=49124121&loc=SL6953423-111524

+ Details

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

- 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=49124121&loc=SL6953423-111524

+ Details

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

- Definition

The balance of financing receivables that were collectively 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 (h)
-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953423-111524

+ Details

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

- Definition

The balance of financing receivables 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 (h)
-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953423-111524

+ Details

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

- Definition

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5074-111524

+ Details

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

- References

No definition available.

+ Details

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

- Details

Name:	us-gaap_ReceivablesAcquiredWithDeterioratedCreditQualityAxis=us-gaap_ReceivablesAcquiredWithDeterioratedCreditQualityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=lcnb_CommercialAndIndustrialMember
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:

- Details

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

- Details

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

Loans, Allowance for Loan Losses and Loan Portfolio by Segment (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Allowance for loan losses:
Individually evaluated for impairment	$ 324	$ 363
Collectively evaluated for impairment	2,797	2,766
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses	29	0
Balance, end of period	3,150	3,129	$ 2,837	$ 3,121
Loans:
Individually evaluated for impairment	15,467	14,318
Collectively evaluated for impairment	752,616	743,952
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	10,631	12,668
Balance, end of period	778,714	770,938
Acquired credit impaired loans [Member]
Loans:
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	10,631	12,668
Commercial and Industrial [Member]
Allowance for loan losses:
Individually evaluated for impairment	8	9
Collectively evaluated for impairment	239	235
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses	0	0
Balance, end of period	247	244	131	129
Loans:
Individually evaluated for impairment	362	370
Collectively evaluated for impairment	44,236	43,726
Balance, end of period	45,337	45,287
Commercial and Industrial [Member] \| Acquired credit impaired loans [Member]
Loans:
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	739	1,191
Commercial Secured By Real Estate [Member]
Allowance for loan losses:
Individually evaluated for impairment	210	306
Collectively evaluated for impairment	1,629	1,602
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses	29	0
Balance, end of period	1,868	1,908	1,640	1,990
Loans:
Individually evaluated for impairment	13,065	12,351
Collectively evaluated for impairment	410,441	399,092
Balance, end of period	429,857	419,320
Commercial Secured By Real Estate [Member] \| Acquired credit impaired loans [Member]
Loans:
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	6,351	7,877
Residential Real Estate [Member]
Allowance for loan losses:
Individually evaluated for impairment	93	48
Collectively evaluated for impairment	803	806
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses	0	0
Balance, end of period	896	854	934	926
Loans:
Individually evaluated for impairment	1,593	1,541
Collectively evaluated for impairment	267,682	269,001
Balance, end of period	272,261	273,581
Residential Real Estate [Member] \| Acquired credit impaired loans [Member]
Loans:
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	2,986	3,039
Consumer [Member]
Allowance for loan losses:
Individually evaluated for impairment	13	0
Collectively evaluated for impairment	68	54
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses	0	0
Balance, end of period	81	54	54	63
Loans:
Individually evaluated for impairment	63	56
Collectively evaluated for impairment	17,934	18,516
Balance, end of period	18,019	18,599
Consumer [Member] \| Acquired credit impaired loans [Member]
Loans:
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	22	27
Agricultural [Member]
Allowance for loan losses:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	56	66
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses	0	0
Balance, end of period	56	66	77	11
Loans:
Individually evaluated for impairment	384	0
Collectively evaluated for impairment	12,184	13,438
Balance, end of period	12,597	13,486
Agricultural [Member] \| Acquired credit impaired loans [Member]
Loans:
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	29	48
Other [Member]
Allowance for loan losses:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	2	3
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses	0	0
Balance, end of period	2	3	$ 1	$ 2
Loans:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	139	179
Balance, end of period	643	665
Other [Member] \| Acquired credit impaired loans [Member]
Loans:
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	$ 504	$ 486