<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.26.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>309</ContextCount>
  <ElementCount>316</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>78</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>11</UnitCount>
  <MyReports>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0000001 - Document - Cover</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/Cover</Role>
      <ShortName>Cover</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>9952151 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETS</Role>
      <ShortName>CONDENSED CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>9952152 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETSParenthetical</Role>
      <ShortName>CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>9952153 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONS</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>9952154 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVELOSS</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>9952155 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>9952156 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITYParenthetical</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>9952157 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWS</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>9952158 - Disclosure - Description of Company and Basis of Presentation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/DescriptionofCompanyandBasisofPresentation</Role>
      <ShortName>Description of Company and Basis of Presentation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>9952159 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/SummaryofSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>9952160 - Disclosure - New Accounting Pronouncements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/NewAccountingPronouncements</Role>
      <ShortName>New Accounting Pronouncements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>9952161 - Disclosure - Dispositions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/Dispositions</Role>
      <ShortName>Dispositions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>9952162 - Disclosure - Accounts Receivable</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/AccountsReceivable</Role>
      <ShortName>Accounts Receivable</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>9952163 - Disclosure - Inventories</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/Inventories</Role>
      <ShortName>Inventories</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>9952164 - Disclosure - Goodwill and Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/GoodwillandIntangibleAssets</Role>
      <ShortName>Goodwill and Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>9952165 - Disclosure - Notes Payable - Floor Plan</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://onewatermarine.com/role/NotesPayableFloorPlan</Role>
      <ShortName>Notes Payable - Floor Plan</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>9952166 - Disclosure - Long-term Debt and Line of Credit</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/LongtermDebtandLineofCredit</Role>
      <ShortName>Long-term Debt and Line of Credit</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>9952167 - Disclosure - Derivative and Hedging Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/DerivativeandHedgingInstruments</Role>
      <ShortName>Derivative and Hedging Instruments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>9952168 - Disclosure - Stockholders??? Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/StockholdersEquity</Role>
      <ShortName>Stockholders??? Equity</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>9952169 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/FairValueMeasurements</Role>
      <ShortName>Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>9952170 - Disclosure - Restructuring and Impairment</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/RestructuringandImpairment</Role>
      <ShortName>Restructuring and Impairment</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>9952171 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>9952172 - Disclosure - Contingencies and Commitments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/ContingenciesandCommitments</Role>
      <ShortName>Contingencies and Commitments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>9952173 - Disclosure - Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/Leases</Role>
      <ShortName>Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>9952174 - Disclosure - Related Party Transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/RelatedPartyTransactions</Role>
      <ShortName>Related Party Transactions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>9952175 - Disclosure - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/SegmentInformation</Role>
      <ShortName>Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>995445 - Disclosure - Insider Trading Arrangements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements</Role>
      <ShortName>Insider Trading Arrangements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>9955511 - Disclosure - Description of Company and Basis of Presentation (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/DescriptionofCompanyandBasisofPresentationPolicies</Role>
      <ShortName>Description of Company and Basis of Presentation (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://onewatermarine.com/role/SummaryofSignificantAccountingPolicies</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>9955512 - Disclosure - Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/SummaryofSignificantAccountingPoliciesTables</Role>
      <ShortName>Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://onewatermarine.com/role/SummaryofSignificantAccountingPolicies</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>9955513 - Disclosure - Accounts Receivable (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/AccountsReceivableTables</Role>
      <ShortName>Accounts Receivable (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://onewatermarine.com/role/AccountsReceivable</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>9955514 - Disclosure - Inventories (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/InventoriesTables</Role>
      <ShortName>Inventories (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://onewatermarine.com/role/Inventories</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>9955515 - Disclosure - Goodwill and Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/GoodwillandIntangibleAssetsTables</Role>
      <ShortName>Goodwill and Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://onewatermarine.com/role/GoodwillandIntangibleAssets</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>9955516 - Disclosure - Long-term Debt and Line of Credit (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/LongtermDebtandLineofCreditTables</Role>
      <ShortName>Long-term Debt and Line of Credit (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://onewatermarine.com/role/LongtermDebtandLineofCredit</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>9955517 - Disclosure - Derivative and Hedging Instruments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/DerivativeandHedgingInstrumentsTables</Role>
      <ShortName>Derivative and Hedging Instruments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://onewatermarine.com/role/DerivativeandHedgingInstruments</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>9955518 - Disclosure - Stockholders??? Equity (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/StockholdersEquityTables</Role>
      <ShortName>Stockholders??? Equity (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://onewatermarine.com/role/StockholdersEquity</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>9955519 - Disclosure - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/FairValueMeasurementsTables</Role>
      <ShortName>Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://onewatermarine.com/role/FairValueMeasurements</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>9955520 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/SegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://onewatermarine.com/role/SegmentInformation</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>9955521 - Disclosure - Description of Company and Basis of Presentation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/DescriptionofCompanyandBasisofPresentationDetails</Role>
      <ShortName>Description of Company and Basis of Presentation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://onewatermarine.com/role/DescriptionofCompanyandBasisofPresentationPolicies</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>9955522 - Disclosure - Summary of Significant Accounting Policies - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/SummaryofSignificantAccountingPoliciesNarrativeDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>9955523 - Disclosure - Summary of Significant Accounting Policies - Summary of Contract Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/SummaryofSignificantAccountingPoliciesSummaryofContractLiabilitiesDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Summary of Contract Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>9955524 - Disclosure - Summary of Significant Accounting Policies - Summary of Percentages on Timing of Revenue Recognition (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/SummaryofSignificantAccountingPoliciesSummaryofPercentagesonTimingofRevenueRecognitionDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Summary of Percentages on Timing of Revenue Recognition (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>9955525 - Disclosure - Discontinued Operations and Disposal Groups (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/DiscontinuedOperationsandDisposalGroupsDetails</Role>
      <ShortName>Discontinued Operations and Disposal Groups (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>9955526 - Disclosure - Accounts Receivable (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/AccountsReceivableDetails</Role>
      <ShortName>Accounts Receivable (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://onewatermarine.com/role/AccountsReceivableTables</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>9955527 - Disclosure - Inventories (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/InventoriesDetails</Role>
      <ShortName>Inventories (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://onewatermarine.com/role/InventoriesTables</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>9955528 - Disclosure - Goodwill and Intangible Assets - Summary of Changes in Goodwill and Identifiable Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/GoodwillandIntangibleAssetsSummaryofChangesinGoodwillandIdentifiableIntangibleAssetsDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Summary of Changes in Goodwill and Identifiable Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>9955529 - Disclosure - Goodwill and Intangible Assets - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/GoodwillandIntangibleAssetsNarrativeDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>9955530 - Disclosure - Goodwill and Intangible Assets - Summary of Expected Amortization Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/GoodwillandIntangibleAssetsSummaryofExpectedAmortizationExpenseDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Summary of Expected Amortization Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>9955531 - Disclosure - Notes Payable - Floor Plan (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://onewatermarine.com/role/NotesPayableFloorPlanDetails</Role>
      <ShortName>Notes Payable - Floor Plan (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://onewatermarine.com/role/NotesPayableFloorPlan</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>9955532 - Disclosure - Long-term Debt and Line of Credit - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/LongtermDebtandLineofCreditNarrativeDetails</Role>
      <ShortName>Long-term Debt and Line of Credit - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>9955533 - Disclosure - Long-term Debt and Line of Credit - Summary of Long-term Debt and Line of Credit (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/LongtermDebtandLineofCreditSummaryofLongtermDebtandLineofCreditDetails</Role>
      <ShortName>Long-term Debt and Line of Credit - Summary of Long-term Debt and Line of Credit (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>9955534 - Disclosure - Derivative and Hedging Instruments - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/DerivativeandHedgingInstrumentsNarrativeDetails</Role>
      <ShortName>Derivative and Hedging Instruments - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>9955535 - Disclosure - Derivative and Hedging Instruments - Notional Value (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/DerivativeandHedgingInstrumentsNotionalValueDetails</Role>
      <ShortName>Derivative and Hedging Instruments - Notional Value (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>9955536 - Disclosure - Derivative and Hedging Instruments - Balance Sheet Location (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/DerivativeandHedgingInstrumentsBalanceSheetLocationDetails</Role>
      <ShortName>Derivative and Hedging Instruments - Balance Sheet Location (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>9955537 - Disclosure - Derivative and Hedging Instruments - Effect of the Interest Rate Swap Agreements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/DerivativeandHedgingInstrumentsEffectoftheInterestRateSwapAgreementsDetails</Role>
      <ShortName>Derivative and Hedging Instruments - Effect of the Interest Rate Swap Agreements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>9955538 - Disclosure - Stockholders??? Equity - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/StockholdersEquityNarrativeDetails</Role>
      <ShortName>Stockholders??? Equity - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>9955539 - Disclosure - Stockholders??? Equity - Summary of Restricted Stock Units Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/StockholdersEquitySummaryofRestrictedStockUnitsActivityDetails</Role>
      <ShortName>Stockholders??? Equity - Summary of Restricted Stock Units Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>9955540 - Disclosure - Stockholders??? Equity - Summary of Net (Loss) Earnings Per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/StockholdersEquitySummaryofNetLossEarningsPerShareDetails</Role>
      <ShortName>Stockholders??? Equity - Summary of Net (Loss) Earnings Per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>9955541 - Disclosure - Stockholders??? Equity - Summary of Antidilutive Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/StockholdersEquitySummaryofAntidilutiveSecuritiesDetails</Role>
      <ShortName>Stockholders??? Equity - Summary of Antidilutive Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>9955542 - Disclosure - Stockholders??? Equity - Summary of Employee Stock Purchase Plan (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/StockholdersEquitySummaryofEmployeeStockPurchasePlanDetails</Role>
      <ShortName>Stockholders??? Equity - Summary of Employee Stock Purchase Plan (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>9955543 - Disclosure - Fair Value Measures - Summary of Financial Assets and Liabilities Measured at Fair Value (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/FairValueMeasuresSummaryofFinancialAssetsandLiabilitiesMeasuredatFairValueDetails</Role>
      <ShortName>Fair Value Measures - Summary of Financial Assets and Liabilities Measured at Fair Value (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>9955544 - Disclosure - Fair Value Measures - Summary of Unrealized Losses Recognized Related to Equity Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/FairValueMeasuresSummaryofUnrealizedLossesRecognizedRelatedtoEquitySecuritiesDetails</Role>
      <ShortName>Fair Value Measures - Summary of Unrealized Losses Recognized Related to Equity Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>9955545 - Disclosure - Fair Value Measures - Summary of Changes in Fair Value of Contingent Consideration (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/FairValueMeasuresSummaryofChangesinFairValueofContingentConsiderationDetails</Role>
      <ShortName>Fair Value Measures - Summary of Changes in Fair Value of Contingent Consideration (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>9955546 - Disclosure - Restructuring and Impairment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/RestructuringandImpairmentDetails</Role>
      <ShortName>Restructuring and Impairment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://onewatermarine.com/role/RestructuringandImpairment</ParentRole>
      <Position>63</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>9955547 - Disclosure - Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/IncomeTaxesDetails</Role>
      <ShortName>Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://onewatermarine.com/role/IncomeTaxes</ParentRole>
      <Position>64</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>9955548 - Disclosure - Leases (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/LeasesDetails</Role>
      <ShortName>Leases (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://onewatermarine.com/role/Leases</ParentRole>
      <Position>65</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>9955549 - Disclosure - Related Party Transactions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/RelatedPartyTransactionsDetails</Role>
      <ShortName>Related Party Transactions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://onewatermarine.com/role/RelatedPartyTransactions</ParentRole>
      <Position>66</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>9955550 - Disclosure - Segment Information - Reportable Segment Financial Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/SegmentInformationReportableSegmentFinancialInformationDetails</Role>
      <ShortName>Segment Information - Reportable Segment Financial Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="onew-20260331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>9955551 - Disclosure - Segment Information - Reconciliation, Interest Expense, Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://onewatermarine.com/role/SegmentInformationReconciliationInterestExpenseAssetsDetails</Role>
      <ShortName>Segment Information - Reconciliation, Interest Expense, Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File doctype="10-Q" isDefinitelyFs="true" isUsgaap="true" original="onew-20260331.htm">onew-20260331.htm</File>
    <File>onew-20260331.xsd</File>
    <File>onew-20260331_cal.xml</File>
    <File>onew-20260331_def.xml</File>
    <File>onew-20260331_lab.xml</File>
    <File>onew-20260331_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy items="1">http://fasb.org/srt/2025</BaseTaxonomy>
    <BaseTaxonomy items="932">http://fasb.org/us-gaap/2025</BaseTaxonomy>
    <BaseTaxonomy items="30">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
    <BaseTaxonomy items="4">http://xbrl.sec.gov/ecd/2025</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
