ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY - Schedule of Financial Effect of the Loan Modifications (Details) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2025 USD ($) loan	Sep. 30, 2025 USD ($) loan
Financing Receivable, Allowance for Credit Loss [Line Items]
Total Modifications	$ 1,994	$ 1,994
Principal Forgiveness
Financing Receivable, Allowance for Credit Loss [Line Items]
Total Modifications	$ 28,607	$ 28,607
Weighted Average Interest Rate Reduction
Financing Receivable, Allowance for Credit Loss [Line Items]
Weighted Average Interest Rate Reduction	7.00%	7.00%
Total commercial loans \| Principal Forgiveness
Financing Receivable, Allowance for Credit Loss [Line Items]
Total Modifications	$ 28,607	$ 28,607
Total commercial loans \| Weighted Average Interest Rate Reduction
Financing Receivable, Allowance for Credit Loss [Line Items]
Weighted Average Interest Rate Reduction	7.00%	7.00%
Total commercial loans \| Commercial and industrial loans: \| Principal Forgiveness
Financing Receivable, Allowance for Credit Loss [Line Items]
Total Modifications	$ 28,607	$ 28,607
Total commercial loans \| Commercial and industrial loans: \| Weighted Average Interest Rate Reduction
Financing Receivable, Allowance for Credit Loss [Line Items]
Weighted Average Interest Rate Reduction	7.00%	7.00%
Total commercial loans \| Commercial and industrial loans: \| Working capital lines of credit loans \| Principal Forgiveness
Financing Receivable, Allowance for Credit Loss [Line Items]
Total Modifications	$ 28,607	$ 28,607
Number of loans \| loan	1,000	1,000
Loans modified In troubled debt restructured loans	$ 30,600	$ 30,600
Loans modified, charged off		28,600
Loans modified, settlement		$ 2,000
Total commercial loans \| Commercial and industrial loans: \| Working capital lines of credit loans \| Weighted Average Interest Rate Reduction
Financing Receivable, Allowance for Credit Loss [Line Items]
Weighted Average Interest Rate Reduction	7.00%	7.00%

Financing Receivable, Excluding Accrued Interest, Modified in Period, Settlement

No definition available.

Name:	lkfn_FinancingReceivableExcludingAccruedInterestModifiedInPeriodSettlement
Namespace Prefix:	lkfn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Financing Receivable, Excluding Accrued Interest, Modified in Period, Writeoff

+ References

No definition available.

+ Details

Name:	lkfn_FinancingReceivableExcludingAccruedInterestModifiedInPeriodWriteoff
Namespace Prefix:	lkfn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Financing Receivable, Modified, Number of Loans

+ References

No definition available.

+ Details

Name:	lkfn_FinancingReceivableModifiedNumberOfLoans
Namespace Prefix:	lkfn_
Data Type:	xbrli:integerItemType
Balance Type:	na
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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph c
-Publisher SEC

+ Details

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

- Definition

Amortized cost excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-42

+ Details

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

- Definition

Accumulated amortized cost of financing receivable modified for debtor experiencing financial difficulty.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-42

Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 33
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-33

Reference 3: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481746/310-40-50-4

+ Details

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

- Definition

Percentage of decrease in weighted average contractual interest rate of financing receivable modified for debtor experiencing financial difficulty.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481933/310-10-55-12A

+ Details

Name:	us-gaap_FinancingReceivableModifiedWeightedAverageInterestRateDecreaseFromModification
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_PrincipalForgivenessMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_ContractualInterestRateReductionMember
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:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=lkfn_TotalCommercialAndIndustrialLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: