FAIR VALUE DISCLOSURES (Valuation Methodology and Unobservable Inputs for Level 3 Assets) (Details) - Non-Recurring [Member] - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2017	Dec. 31, 2016
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Impaired loans	$ 6,264	$ 5,767
Commercial and Industrial Loans [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Impaired loans	$ 5,354	$ 4,510
Valuation Methodology	Collateral based measurements	Collateral based measurements
Unobservable Inputs	Discount to reflect current market conditions and ultimate collectability	Discount to reflect current market conditions and ultimate collectability
Commercial and Industrial Loans [Member] \| Minimum [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Range of Inputs (Average) (in hundredths)	23.00%	22.00%
Commercial and Industrial Loans [Member] \| Maximum [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Range of Inputs (Average) (in hundredths)	100.00%	100.00%
Commercial and Industrial Loans [Member] \| Weighted Average [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Range of Inputs (Average) (in hundredths)	37.00%	44.00%
Commercial Real Estate and Multi-Family Residential Loans [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Impaired loans	$ 910	$ 1,195
Valuation Methodology	Collateral based measurements
Unobservable Inputs	Discount to reflect current market conditions and ultimate collectability	Discount to reflect current market conditions and ultimate collectability
Commercial Real Estate and Multi-Family Residential Loans [Member] \| Minimum [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Range of Inputs (Average) (in hundredths)	3.00%	6.00%
Commercial Real Estate and Multi-Family Residential Loans [Member] \| Maximum [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Range of Inputs (Average) (in hundredths)	60.00%	59.00%
Commercial Real Estate and Multi-Family Residential Loans [Member] \| Weighted Average [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Range of Inputs (Average) (in hundredths)	38.00%	30.00%
Consumer 1-4 Family Mortgage Loans [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Impaired loans		$ 62
Valuation Methodology		Collateral based measurements
Unobservable Inputs		Discount to reflect current market conditions and ultimate collectability
Consumer 1-4 Family Mortgage Loans [Member] \| Weighted Average [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Range of Inputs (Average) (in hundredths)		15.00%
Other Real Estate Owned [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Impaired loans	$ 75	$ 75
Valuation Methodology	Appraisals	Appraisals
Unobservable Inputs	Discount to reflect current market conditions	Discount to reflect current market conditions
Other Real Estate Owned [Member] \| Weighted Average [Member]
Valuation Methodology and Unobservable Inputs For Level 3 Assets Measured At Fair Value [Line Items]
Range of Inputs (Average) (in hundredths)	49.00%	49.00%

This element represents the aggregate of the impaired loans reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

No definition available.

+ Details

Name:	lkfn_ImpairedLoansFairValueDisclosure
Namespace Prefix:	lkfn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The description of the unobservable input used to measure the fair value of assets at the end of the period.

+ References

No definition available.

+ Details

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Namespace Prefix:	lkfn_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

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Namespace Prefix:	lkfn_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

+ Details

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- Definition

Description of the inputs and valuation technique(s) used to measure fair value.

+ References

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