No definition available.

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

- Definition

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

+ References

+ 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

+ 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

+ 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

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (b)(1)(ii)
-URI http://asc.fasb.org/extlink&oid=121614798&loc=d3e15032-111544

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB Topic 6.L.1)
-URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74567-122707

+ Details

Name:	us-gaap_LoansAndLeasesReceivableAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121593590&loc=d3e4428-111522

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5074-111524

+ Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY - Balance In The Allowance For Loan Losses And The Recorded Investment In Loans By Portfolio Management (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Ending allowance balance attributable to loans:
Individually evaluated for impairment		$ 8,041
Collectively evaluated for impairment		53,367
Total ending allowance balance	$ 71,844	61,408	$ 53,609	$ 50,652
Loans:
Loans individually evaluated for impairment		20,179
Loans collectively evaluated for impairment		4,628,977
Total ending loans balance	4,474,631	4,649,156
Commercial and industrial loans
Ending allowance balance attributable to loans:
Individually evaluated for impairment		6,310
Collectively evaluated for impairment		22,023
Total ending allowance balance	32,052	28,333	24,739	25,789
Loans:
Loans individually evaluated for impairment		12,533
Loans collectively evaluated for impairment		1,772,393
Total ending loans balance		1,784,926
Commercial real estate and multi-family residential loans
Ending allowance balance attributable to loans:
Individually evaluated for impairment		1,377
Collectively evaluated for impairment		21,530
Total ending allowance balance	29,445	22,907	18,658	15,796
Loans:
Loans individually evaluated for impairment		5,518
Loans collectively evaluated for impairment		1,887,054
Total ending loans balance		1,892,572
Agri-business and agricultural loans
Ending allowance balance attributable to loans:
Individually evaluated for impairment		84
Collectively evaluated for impairment		2,959
Total ending allowance balance	3,901	3,043	3,704	3,869
Loans:
Loans individually evaluated for impairment		428
Loans collectively evaluated for impairment		429,234
Total ending loans balance		429,662
Other Commercial
Ending allowance balance attributable to loans:
Individually evaluated for impairment		0
Collectively evaluated for impairment		416
Total ending allowance balance	1,172	416	521	447
Loans:
Loans individually evaluated for impairment		0
Loans collectively evaluated for impairment		93,912
Total ending loans balance		93,912
Consumer 1-4 family loans
Ending allowance balance attributable to loans:
Individually evaluated for impairment		270
Collectively evaluated for impairment		2,349
Total ending allowance balance	3,384	2,619	2,475	2,086
Loans:
Loans individually evaluated for impairment		1,700
Loans collectively evaluated for impairment		342,999
Total ending loans balance		344,699
Other Consumer
Ending allowance balance attributable to loans:
Individually evaluated for impairment		0
Collectively evaluated for impairment		951
Total ending allowance balance	1,293	951	447	345
Loans:
Loans individually evaluated for impairment		0
Loans collectively evaluated for impairment		103,385
Total ending loans balance		103,385
Unallocated
Ending allowance balance attributable to loans:
Individually evaluated for impairment		0
Collectively evaluated for impairment		3,139
Total ending allowance balance	$ 597	3,139	$ 3,065	$ 2,320
Loans:
Loans individually evaluated for impairment		0
Loans collectively evaluated for impairment		0
Total ending loans balance		$ 0