<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.22.2.2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>601</ContextCount>
  <ElementCount>378</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>99</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>8</UnitCount>
  <MyReports>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0001001 - Document - Cover Page</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/CoverPage</Role>
      <ShortName>Cover Page</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001002 - Statement - CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/CONSOLIDATEDBALANCESHEETS</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1002003 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/CONSOLIDATEDBALANCESHEETSParenthetical</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1003004 - Statement - CONSOLIDATED STATEMENTS OF INCOME (unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/CONSOLIDATEDSTATEMENTSOFINCOMEunaudited</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF INCOME (unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1004005 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSSunaudited</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1005006 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/CONSOLIDATEDSTATEMENTSOFCHANGESINSTOCKHOLDERSEQUITYunaudited</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>1006007 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (unaudited) (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/CONSOLIDATEDSTATEMENTSOFCHANGESINSTOCKHOLDERSEQUITYunauditedParenthetical</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (unaudited) (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>1007008 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWSunaudited</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2101101 - Disclosure - BASIS OF PRESENTATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/BASISOFPRESENTATION</Role>
      <ShortName>BASIS OF PRESENTATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2104102 - Disclosure - SECURITIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/SECURITIES</Role>
      <ShortName>SECURITIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2113103 - Disclosure - LOANS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/LOANS</Role>
      <ShortName>LOANS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2117104 - Disclosure - ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/ALLOWANCEFORCREDITLOSSESANDCREDITQUALITY</Role>
      <ShortName>ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2125105 - Disclosure - BORROWINGS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/BORROWINGS</Role>
      <ShortName>BORROWINGS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2128106 - Disclosure - FAIR VALUE DISCLOSURES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/FAIRVALUEDISCLOSURES</Role>
      <ShortName>FAIR VALUE DISCLOSURES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2135107 - Disclosure - OFFSETTING ASSETS AND LIABILITIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/OFFSETTINGASSETSANDLIABILITIES</Role>
      <ShortName>OFFSETTING ASSETS AND LIABILITIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2138108 - Disclosure - EARNINGS PER SHARE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/EARNINGSPERSHARE</Role>
      <ShortName>EARNINGS PER SHARE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2141109 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSS</Role>
      <ShortName>ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2145110 - Disclosure - LEASES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/LEASES</Role>
      <ShortName>LEASES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2150111 - Disclosure - CONTINGENCIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/CONTINGENCIES</Role>
      <ShortName>CONTINGENCIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2202201 - Disclosure - BASIS OF PRESENTATION (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/BASISOFPRESENTATIONPolicies</Role>
      <ShortName>BASIS OF PRESENTATION (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2305301 - Disclosure - SECURITIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/SECURITIESTables</Role>
      <ShortName>SECURITIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lakeland.com/role/SECURITIES</ParentRole>
      <Position>21</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2314302 - Disclosure - LOANS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/LOANSTables</Role>
      <ShortName>LOANS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lakeland.com/role/LOANS</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2318303 - Disclosure - ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/ALLOWANCEFORCREDITLOSSESANDCREDITQUALITYTables</Role>
      <ShortName>ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lakeland.com/role/ALLOWANCEFORCREDITLOSSESANDCREDITQUALITY</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2329304 - Disclosure - FAIR VALUE DISCLOSURES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/FAIRVALUEDISCLOSURESTables</Role>
      <ShortName>FAIR VALUE DISCLOSURES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lakeland.com/role/FAIRVALUEDISCLOSURES</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2336305 - Disclosure - OFFSETTING ASSETS AND LIABILITIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/OFFSETTINGASSETSANDLIABILITIESTables</Role>
      <ShortName>OFFSETTING ASSETS AND LIABILITIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lakeland.com/role/OFFSETTINGASSETSANDLIABILITIES</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2339306 - Disclosure - EARNINGS PER SHARE (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/EARNINGSPERSHARETables</Role>
      <ShortName>EARNINGS PER SHARE (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lakeland.com/role/EARNINGSPERSHARE</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2342307 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSTables</Role>
      <ShortName>ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lakeland.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSS</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2346308 - Disclosure - LEASES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/LEASESTables</Role>
      <ShortName>LEASES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lakeland.com/role/LEASES</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2403401 - Disclosure - BASIS OF PRESENTATION (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/BASISOFPRESENTATIONDetails</Role>
      <ShortName>BASIS OF PRESENTATION (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lakeland.com/role/BASISOFPRESENTATIONPolicies</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2406402 - Disclosure - SECURITIES - Summary of Available For Sale and Held to Maturity Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/SECURITIESSummaryofAvailableForSaleandHeldtoMaturitySecuritiesDetails</Role>
      <ShortName>SECURITIES - Summary of Available For Sale and Held to Maturity Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2407403 - Disclosure - SECURITIES - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/SECURITIESAdditionalInformationDetails</Role>
      <ShortName>SECURITIES - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2408404 - Disclosure - SECURITIES - Schedule of Securities By Maturity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/SECURITIESScheduleofSecuritiesByMaturityDetails</Role>
      <ShortName>SECURITIES - Schedule of Securities By Maturity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2409405 - Disclosure - SECURITIES - Schedule of Sales of Securities Available For Sale (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/SECURITIESScheduleofSalesofSecuritiesAvailableForSaleDetails</Role>
      <ShortName>SECURITIES - Schedule of Sales of Securities Available For Sale (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2410406 - Disclosure - SECURITIES - Unrealized Loss Analysis on Available-for-Sale and Held-to-Maturity Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/SECURITIESUnrealizedLossAnalysisonAvailableforSaleandHeldtoMaturitySecuritiesDetails</Role>
      <ShortName>SECURITIES - Unrealized Loss Analysis on Available-for-Sale and Held-to-Maturity Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2411407 - Disclosure - SECURITIES - Quantitative Disclosure of Available For Sale of Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/SECURITIESQuantitativeDisclosureofAvailableForSaleofSecuritiesDetails</Role>
      <ShortName>SECURITIES - Quantitative Disclosure of Available For Sale of Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2412408 - Disclosure - SECURITIES - Quantitative Disclosure of Held to Maturity Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/SECURITIESQuantitativeDisclosureofHeldtoMaturitySecuritiesDetails</Role>
      <ShortName>SECURITIES - Quantitative Disclosure of Held to Maturity Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2415409 - Disclosure - LOANS - Total Loans Outstanding (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/LOANSTotalLoansOutstandingDetails</Role>
      <ShortName>LOANS - Total Loans Outstanding (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2416410 - Disclosure - LOANS - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/LOANSAdditionalInformationDetails</Role>
      <ShortName>LOANS - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2419411 - Disclosure - ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY - Allowance for loan losses by portfolio segment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/ALLOWANCEFORCREDITLOSSESANDCREDITQUALITYAllowanceforloanlossesbyportfoliosegmentDetails</Role>
      <ShortName>ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY - Allowance for loan losses by portfolio segment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2420412 - Disclosure - ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/ALLOWANCEFORCREDITLOSSESANDCREDITQUALITYAdditionalInformationDetails</Role>
      <ShortName>ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2421413 - Disclosure - ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY - Risk category of loans by loan segment and origination (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/ALLOWANCEFORCREDITLOSSESANDCREDITQUALITYRiskcategoryofloansbyloansegmentandoriginationDetails</Role>
      <ShortName>ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY - Risk category of loans by loan segment and origination (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2422414 - Disclosure - ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY - Aging Of The Amortized Cost In Past Due Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/ALLOWANCEFORCREDITLOSSESANDCREDITQUALITYAgingOfTheAmortizedCostInPastDueLoansDetails</Role>
      <ShortName>ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY - Aging Of The Amortized Cost In Past Due Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2423415 - Disclosure - ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY - Amortized Cost Basis Of Collateral Dependent Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/ALLOWANCEFORCREDITLOSSESANDCREDITQUALITYAmortizedCostBasisOfCollateralDependentLoansDetails</Role>
      <ShortName>ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY - Amortized Cost Basis Of Collateral Dependent Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>2424416 - Disclosure - ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY - Trouble Debt Restructurings (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/ALLOWANCEFORCREDITLOSSESANDCREDITQUALITYTroubleDebtRestructuringsDetails</Role>
      <ShortName>ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY - Trouble Debt Restructurings (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>2426417 - Disclosure - BORROWINGS - Long-term Borrowings (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/BORROWINGSLongtermBorrowingsDetails</Role>
      <ShortName>BORROWINGS - Long-term Borrowings (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>2427418 - Disclosure - BORROWINGS - Revolving Credit Agreement (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/BORROWINGSRevolvingCreditAgreementDetails</Role>
      <ShortName>BORROWINGS - Revolving Credit Agreement (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>2430419 - Disclosure - FAIR VALUE DISCLOSURES - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/FAIRVALUEDISCLOSURESAdditionalInformationDetails</Role>
      <ShortName>FAIR VALUE DISCLOSURES - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>2431420 - Disclosure - FAIR VALUE DISCLOSURES - Assets and Liabilities Measured At Fair Value on a Recurring Basis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/FAIRVALUEDISCLOSURESAssetsandLiabilitiesMeasuredAtFairValueonaRecurringBasisDetails</Role>
      <ShortName>FAIR VALUE DISCLOSURES - Assets and Liabilities Measured At Fair Value on a Recurring Basis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>2432421 - Disclosure - FAIR VALUE DISCLOSURES - Assets Measured at Fair Value on a Nonrecurring Basis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/FAIRVALUEDISCLOSURESAssetsMeasuredatFairValueonaNonrecurringBasisDetails</Role>
      <ShortName>FAIR VALUE DISCLOSURES - Assets Measured at Fair Value on a Nonrecurring Basis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>2433422 - Disclosure - FAIR VALUE DISCLOSURES - Valuation Methodology and Unobservable Inputs for Level 3 Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/FAIRVALUEDISCLOSURESValuationMethodologyandUnobservableInputsforLevel3AssetsDetails</Role>
      <ShortName>FAIR VALUE DISCLOSURES - Valuation Methodology and Unobservable Inputs for Level 3 Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>2434423 - Disclosure - FAIR VALUE DISCLOSURES - Estimated Fair Values And The Related Carrying Values Of Financial Instruments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/FAIRVALUEDISCLOSURESEstimatedFairValuesAndTheRelatedCarryingValuesOfFinancialInstrumentsDetails</Role>
      <ShortName>FAIR VALUE DISCLOSURES - Estimated Fair Values And The Related Carrying Values Of Financial Instruments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>2437424 - Disclosure - OFFSETTING ASSETS AND LIABILITIES - Schedule of Offsetting of Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/OFFSETTINGASSETSANDLIABILITIESScheduleofOffsettingofAssetsandLiabilitiesDetails</Role>
      <ShortName>OFFSETTING ASSETS AND LIABILITIES - Schedule of Offsetting of Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>2440425 - Disclosure - EARNINGS PER SHARE - Earnings Per Share Computations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/EARNINGSPERSHAREEarningsPerShareComputationsDetails</Role>
      <ShortName>EARNINGS PER SHARE - Earnings Per Share Computations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>2443426 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE INCOME - Changes in Accumulated Other Comprehensive Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMEChangesinAccumulatedOtherComprehensiveIncomeDetails</Role>
      <ShortName>ACCUMULATED OTHER COMPREHENSIVE INCOME - Changes in Accumulated Other Comprehensive Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>2444427 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE INCOME - Reclassifications (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMEReclassificationsDetails</Role>
      <ShortName>ACCUMULATED OTHER COMPREHENSIVE INCOME - Reclassifications (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>2447428 - Disclosure - LEASES - Maturity Analysis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/LEASESMaturityAnalysisDetails</Role>
      <ShortName>LEASES - Maturity Analysis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>2448429 - Disclosure - LEASES - Lease Cost (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/LEASESLeaseCostDetails</Role>
      <ShortName>LEASES - Lease Cost (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="lkfn-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>2449430 - Disclosure - LEASES - Other Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lakeland.com/role/LEASESOtherInformationDetails</Role>
      <ShortName>LEASES - Other Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <Logs>
    <Log type="Warning">[ix-0514-Hidden-Fact-Eligible-For-Transform] WARN: 3 fact(s) appearing in ix:hidden were eligible for transformation: lkfn:PercentageOfVariance -  lkfn-20220930.htm 4</Log>
  </Logs>
  <InputFiles>
    <File doctype="10-Q" original="lkfn-20220930.htm">lkfn-20220930.htm</File>
    <File>exhibit311-q32022.htm</File>
    <File>exhibit312-q32022.htm</File>
    <File>exhibit321-q32022.htm</File>
    <File>exhibit322-q32022.htm</File>
    <File>lkfn-20220930.xsd</File>
    <File>lkfn-20220930_cal.xml</File>
    <File>lkfn-20220930_def.xml</File>
    <File>lkfn-20220930_lab.xml</File>
    <File>lkfn-20220930_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy items="2124">http://fasb.org/us-gaap/2022</BaseTaxonomy>
    <BaseTaxonomy items="29">http://xbrl.sec.gov/dei/2022</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
