<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.22.2.2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>197</ContextCount>
  <ElementCount>315</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>52</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>5</UnitCount>
  <MyReports>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>00090 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>00100 - Statement - Condensed Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/StatementCondensedConsolidatedBalanceSheets</Role>
      <ShortName>Condensed Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>00105 - Statement - Condensed Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Condensed Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>00200 - Statement - Condensed Consolidated Statements of Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/StatementCondensedConsolidatedStatementsOfOperations</Role>
      <ShortName>Condensed Consolidated Statements of Operations</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>00300 - Statement - Condensed Consolidated Statements of Comprehensive Income (Loss)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss</Role>
      <ShortName>Condensed Consolidated Statements of Comprehensive Income (Loss)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>00400 - Statement - Condensed Consolidated Statements of Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity</Role>
      <ShortName>Condensed Consolidated Statements of Stockholders' Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>00405 - Statement - Condensed Consolidated Statements of Stockholders' Equity - (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquityParenthetical</Role>
      <ShortName>Condensed Consolidated Statements of Stockholders' Equity - (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>00500 - Statement - Condensed Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/StatementCondensedConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Condensed Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>10101 - Disclosure - NATURE OF THE BUSINESS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureNatureOfBusiness</Role>
      <ShortName>NATURE OF THE BUSINESS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>10201 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>10301 - Disclosure - ACQUISITION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureAcquisition</Role>
      <ShortName>ACQUISITION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>10401 - Disclosure - FAIR VALUE MEASUREMENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureFairValueMeasurements</Role>
      <ShortName>FAIR VALUE MEASUREMENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>10501 - Disclosure - GOODWILL AND INTANGIBLE ASSETS, NET</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureGoodwillAndIntangibleAssetsNet</Role>
      <ShortName>GOODWILL AND INTANGIBLE ASSETS, NET</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>10601 - Disclosure - INVENTORIES, NET</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureInventoriesNet</Role>
      <ShortName>INVENTORIES, NET</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>10701 - Disclosure - LONG-TERM DEBT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureLongTermDebt</Role>
      <ShortName>LONG-TERM DEBT</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>10801 - Disclosure - PRODUCT WARRANTIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureProductWarranties</Role>
      <ShortName>PRODUCT WARRANTIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>10901 - Disclosure - LEASES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureLeases</Role>
      <ShortName>LEASES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>11001 - Disclosure - NET SALES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureNetSales</Role>
      <ShortName>NET SALES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>11101 - Disclosure - INCOME TAXES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureIncomeTaxes</Role>
      <ShortName>INCOME TAXES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>11201 - Disclosure - SHAREHOLDERS' EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureShareholdersEquity</Role>
      <ShortName>SHAREHOLDERS' EQUITY</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>11301 - Disclosure - STOCK-BASED COMPENSATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureStockBasedCompensation</Role>
      <ShortName>STOCK-BASED COMPENSATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>11401 - Disclosure - NET INCOME (LOSS) PER SHARE</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureNetIncomeLossPerShare</Role>
      <ShortName>NET INCOME (LOSS) PER SHARE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>11501 - Disclosure - RELATED PARTY TRANSACTIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureRelatedPartyTransactions</Role>
      <ShortName>RELATED PARTY TRANSACTIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>11601 - Disclosure - SUBSEQUENT EVENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureSubsequentEvents</Role>
      <ShortName>SUBSEQUENT EVENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>20202 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>30303 - Disclosure - ACQUISITION (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureAcquisitionTables</Role>
      <ShortName>ACQUISITION (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lathampool.com/role/DisclosureAcquisition</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>30403 - Disclosure - FAIR VALUE MEASUREMENTS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureFairValueMeasurementsTables</Role>
      <ShortName>FAIR VALUE MEASUREMENTS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lathampool.com/role/DisclosureFairValueMeasurements</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>30503 - Disclosure - GOODWILL AND INTANGIBLE ASSETS, NET (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureGoodwillAndIntangibleAssetsNetTables</Role>
      <ShortName>GOODWILL AND INTANGIBLE ASSETS, NET (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lathampool.com/role/DisclosureGoodwillAndIntangibleAssetsNet</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>30603 - Disclosure - INVENTORIES, NET (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureInventoriesNetTables</Role>
      <ShortName>INVENTORIES, NET (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lathampool.com/role/DisclosureInventoriesNet</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>30703 - Disclosure - LONG-TERM DEBT (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureLongTermDebtTables</Role>
      <ShortName>LONG-TERM DEBT (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lathampool.com/role/DisclosureLongTermDebt</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>30803 - Disclosure - PRODUCT WARRANTIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureProductWarrantiesTables</Role>
      <ShortName>PRODUCT WARRANTIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lathampool.com/role/DisclosureProductWarranties</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>30903 - Disclosure - LEASES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureLeasesTables</Role>
      <ShortName>LEASES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lathampool.com/role/DisclosureLeases</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>31003 - Disclosure - NET SALES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureNetSalesTables</Role>
      <ShortName>NET SALES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lathampool.com/role/DisclosureNetSales</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>31303 - Disclosure - STOCK-BASED COMPENSATION (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureStockBasedCompensationTables</Role>
      <ShortName>STOCK-BASED COMPENSATION (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lathampool.com/role/DisclosureStockBasedCompensation</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>31403 - Disclosure - NET INCOME (LOSS) PER SHARE (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureNetIncomeLossPerShareTables</Role>
      <ShortName>NET INCOME (LOSS) PER SHARE (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.lathampool.com/role/DisclosureNetIncomeLossPerShare</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>40201 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Segment Reporting (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureSummaryOfSignificantAccountingPoliciesSegmentReportingDetails</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Segment Reporting (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>40202 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Adoption of ASU 2016-02 (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAdoptionOfAsu201602Details</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Adoption of ASU 2016-02 (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>40301 - Disclosure - ACQUISITION - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureAcquisitionNarrativeDetails</Role>
      <ShortName>ACQUISITION - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>40302 - Disclosure - ACQUISITION - Purchase price allocation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureAcquisitionPurchasePriceAllocationDetails</Role>
      <ShortName>ACQUISITION - Purchase price allocation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>40303 - Disclosure - ACQUISITION - Allocation of purchase price (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureAcquisitionAllocationOfPurchasePriceDetails</Role>
      <ShortName>ACQUISITION - Allocation of purchase price (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>40401 - Disclosure - FAIR VALUE MEASUREMENTS - Fair value of financial instruments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureFairValueMeasurementsFairValueOfFinancialInstrumentsDetails</Role>
      <ShortName>FAIR VALUE MEASUREMENTS - Fair value of financial instruments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>40501 - Disclosure - GOODWILL AND INTANGIBLE ASSETS, NET - Goodwill (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureGoodwillAndIntangibleAssetsNetGoodwillDetails</Role>
      <ShortName>GOODWILL AND INTANGIBLE ASSETS, NET - Goodwill (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>40502 - Disclosure - GOODWILL AND INTANGIBLE ASSETS, NET - Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureGoodwillAndIntangibleAssetsNetIntangibleAssetsDetails</Role>
      <ShortName>GOODWILL AND INTANGIBLE ASSETS, NET - Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>40503 - Disclosure - GOODWILL AND INTANGIBLE ASSETS, NET - Amortization Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureGoodwillAndIntangibleAssetsNetAmortizationExpenseDetails</Role>
      <ShortName>GOODWILL AND INTANGIBLE ASSETS, NET - Amortization Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>40601 - Disclosure - INVENTORIES, NET (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureInventoriesNetDetails</Role>
      <ShortName>INVENTORIES, NET (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lathampool.com/role/DisclosureInventoriesNetTables</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>40701 - Disclosure - LONG-TERM DEBT (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureLongTermDebtDetails</Role>
      <ShortName>LONG-TERM DEBT (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lathampool.com/role/DisclosureLongTermDebtTables</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>40702 - Disclosure - LONG-TERM DEBT - New Revolving Credit Facility (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureLongTermDebtNewRevolvingCreditFacilityDetails</Role>
      <ShortName>LONG-TERM DEBT - New Revolving Credit Facility (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>40703 - Disclosure - LONG-TERM DEBT - New Term Loan Facility (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureLongTermDebtNewTermLoanFacilityDetails</Role>
      <ShortName>LONG-TERM DEBT - New Term Loan Facility (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>40704 - Disclosure - LONG-TERM DEBT - Term Loan Facility (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureLongTermDebtTermLoanFacilityDetails</Role>
      <ShortName>LONG-TERM DEBT - Term Loan Facility (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>40705 - Disclosure - LONG-TERM DEBT - Interest rate swap (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureLongTermDebtInterestRateSwapDetails</Role>
      <ShortName>LONG-TERM DEBT - Interest rate swap (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>40706 - Disclosure - LONG-TERM DEBT - Principal payments due (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureLongTermDebtPrincipalPaymentsDueDetails</Role>
      <ShortName>LONG-TERM DEBT - Principal payments due (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>40801 - Disclosure - PRODUCT WARRANTIES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureProductWarrantiesDetails</Role>
      <ShortName>PRODUCT WARRANTIES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lathampool.com/role/DisclosureProductWarrantiesTables</ParentRole>
      <Position>52</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>40901 - Disclosure - LEASES - Lease expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureLeasesLeaseExpenseDetails</Role>
      <ShortName>LEASES - Lease expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>40902 - Disclosure - LEASES - Supplemental information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureLeasesSupplementalInformationDetails</Role>
      <ShortName>LEASES - Supplemental information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>40903 - Disclosure - LEASES - Maturities of operating lease liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails</Role>
      <ShortName>LEASES - Maturities of operating lease liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>41001 - Disclosure - NET SALES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureNetSalesDetails</Role>
      <ShortName>NET SALES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lathampool.com/role/DisclosureNetSalesTables</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>41101 - Disclosure - INCOME TAXES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureIncomeTaxesDetails</Role>
      <ShortName>INCOME TAXES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lathampool.com/role/DisclosureIncomeTaxes</ParentRole>
      <Position>57</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>41201 - Disclosure - SHAREHOLDERS' EQUITY (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureShareholdersEquityDetails</Role>
      <ShortName>SHAREHOLDERS' EQUITY (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lathampool.com/role/DisclosureShareholdersEquity</ParentRole>
      <Position>58</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>41301 - Disclosure - STOCK-BASED COMPENSATION - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureStockBasedCompensationNarrativeDetails</Role>
      <ShortName>STOCK-BASED COMPENSATION - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>41302 - Disclosure - STOCK-BASED COMPENSATION - Weighted average basis for fair value option award granted (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureStockBasedCompensationWeightedAverageBasisForFairValueOptionAwardGrantedDetails</Role>
      <ShortName>STOCK-BASED COMPENSATION - Weighted average basis for fair value option award granted (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>41303 - Disclosure - STOCK-BASED COMPENSATION - Restricted Stock Awards (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureStockBasedCompensationRestrictedStockAwardsDetails</Role>
      <ShortName>STOCK-BASED COMPENSATION - Restricted Stock Awards (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>41304 - Disclosure - STOCK-BASED COMPENSATION - Restricted Stock Units (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureStockBasedCompensationRestrictedStockUnitsDetails</Role>
      <ShortName>STOCK-BASED COMPENSATION - Restricted Stock Units (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>41306 - Disclosure - STOCK-BASED COMPENSATION - Stock Options (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureStockBasedCompensationStockOptionsDetails</Role>
      <ShortName>STOCK-BASED COMPENSATION - Stock Options (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>41401 - Disclosure - NET INCOME (LOSS) PER SHARE (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureNetIncomeLossPerShareDetails</Role>
      <ShortName>NET INCOME (LOSS) PER SHARE (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.lathampool.com/role/DisclosureNetIncomeLossPerShareTables</ParentRole>
      <Position>64</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>41501 - Disclosure - RELATED PARTY TRANSACTIONS - Bright AI Services (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureRelatedPartyTransactionsBrightAiServicesDetails</Role>
      <ShortName>RELATED PARTY TRANSACTIONS - Bright AI Services (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="swim-20221001x10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>41502 - Disclosure - RELATED PARTY TRANSACTIONS - Expense Reimbursement and Management Fees (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.lathampool.com/role/DisclosureRelatedPartyTransactionsExpenseReimbursementAndManagementFeesDetails</Role>
      <ShortName>RELATED PARTY TRANSACTIONS - Expense Reimbursement and Management Fees (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</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: 6 fact(s) appearing in ix:hidden were eligible for transformation: us-gaap:CommonStockSharesOutstanding, us-gaap:LineOfCredit, us-gaap:NumberOfReportableSegments, us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2, us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageRemainingContractualTerm1 -  swim-20221001x10q.htm 9</Log>
    <Log type="Warning">[ix-0514-Hidden-Fact-Not-Referenced] WARN: 2 fact(s) appearing in ix:hidden were not referenced by any -sec-ix-hidden style property: us-gaap:CommitmentsAndContingencies -  swim-20221001x10q.htm 9</Log>
  </Logs>
  <InputFiles>
    <File doctype="10-Q" original="swim-20221001x10q.htm">swim-20221001x10q.htm</File>
    <File>swim-20221001.xsd</File>
    <File>swim-20221001_cal.xml</File>
    <File>swim-20221001_def.xml</File>
    <File>swim-20221001_lab.xml</File>
    <File>swim-20221001_pre.xml</File>
    <File>swim-20221001xex31d1.htm</File>
    <File>swim-20221001xex31d2.htm</File>
    <File>swim-20221001xex32d1.htm</File>
    <File>swim-20221001xex32d2.htm</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy items="709">http://fasb.org/us-gaap/2021-01-31</BaseTaxonomy>
    <BaseTaxonomy items="30">http://xbrl.sec.gov/dei/2021q4</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
