<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.21.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>237</ContextCount>
  <ElementCount>351</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>80</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>11</UnitCount>
  <MyReports>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>100000 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>100010 - Statement - Condensed Consolidated Balance Sheets (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/StatementCondensedConsolidatedBalanceSheetsUnaudited</Role>
      <ShortName>Condensed Consolidated Balance Sheets (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>100020 - Statement - Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/StatementCondensedConsolidatedBalanceSheetsUnauditedParenthetical</Role>
      <ShortName>Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>100030 - Statement - Condensed Consolidated Statements of Operations (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/StatementCondensedConsolidatedStatementsOfOperationsUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Operations (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>100040 - Statement - Condensed Consolidated Statements of Cash Flows (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/StatementCondensedConsolidatedStatementsOfCashFlowsUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Cash Flows (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>100050 - Statement - Consolidated Statements of Changes in Equity (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/StatementConsolidatedStatementsOfChangesInEquityUnaudited</Role>
      <ShortName>Consolidated Statements of Changes in Equity (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>100060 - Disclosure -  Organization and Business Description</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureOrganizationAndBusinessDescription</Role>
      <ShortName>Organization and Business Description</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>100070 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>100080 - Disclosure - Revenue</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureRevenue</Role>
      <ShortName>Revenue</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>100090 - Disclosure - Concentrations, Risks and Uncertainties</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureConcentrationsRisksAndUncertainties</Role>
      <ShortName>Concentrations, Risks and Uncertainties</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>100100 - Disclosure - Inventories</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureInventories</Role>
      <ShortName>Inventories</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>100110 - Disclosure - Property and Equipment, Net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosurePropertyAndEquipmentNet</Role>
      <ShortName>Property and Equipment, Net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>100120 - Disclosure - Goodwill and Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureGoodwillAndIntangibleAssets</Role>
      <ShortName>Goodwill and Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>100130 - Disclosure - Lines of Credit</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureLinesOfCredit</Role>
      <ShortName>Lines of Credit</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>100140 - Disclosure - Long-Term Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureLongTermDebt</Role>
      <ShortName>Long-Term Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>100150 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureCommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>100160 - Disclosure - Stock Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureStockCompensation</Role>
      <ShortName>Stock Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>100170 - Disclosure - Provision for Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureProvisionForIncomeTaxes</Role>
      <ShortName>Provision for Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>100180 - Disclosure - Related Party Transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureRelatedPartyTransactions</Role>
      <ShortName>Related Party Transactions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>100190 - Disclosure - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureSegmentInformation</Role>
      <ShortName>Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>100200 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureSubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>100210 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>100220 - Disclosure - Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>100230 - Disclosure - Revenue (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureRevenueTables</Role>
      <ShortName>Revenue (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureRevenue</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>100240 - Disclosure - Inventories (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureInventoriesTables</Role>
      <ShortName>Inventories (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureInventories</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>100250 - Disclosure - Property and Equipment, Net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosurePropertyAndEquipmentNetTables</Role>
      <ShortName>Property and Equipment, Net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosurePropertyAndEquipmentNet</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>100260 - Disclosure - Goodwill and Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsTables</Role>
      <ShortName>Goodwill and Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureGoodwillAndIntangibleAssets</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>100270 - Disclosure - Long-Term Debt (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureLongTermDebtTables</Role>
      <ShortName>Long-Term Debt (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureLongTermDebt</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>100280 - Disclosure - Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureCommitmentsAndContingenciesTables</Role>
      <ShortName>Commitments and Contingencies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureCommitmentsAndContingencies</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>100290 - Disclosure - Stock Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureStockCompensationTables</Role>
      <ShortName>Stock Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureStockCompensation</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>100300 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureSegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureSegmentInformation</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>100310 - Disclosure - Summary of Significant Accounting Policies - Schedule of Computation of Basic and Diluted Earnings/(Loss) per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesScheduleOfComputationOfBasicAndDilutedEarningsLossPerShareDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Schedule of Computation of Basic and Diluted Earnings/(Loss) per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>100320 - Disclosure - Summary of Significant Accounting Policies - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesAdditionalInformationDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>100330 - Disclosure - Summary of Significant Accounting Policies - Schedule of Estimated Useful Lives Definite Lived Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesScheduleOfEstimatedUsefulLivesDefiniteLivedIntangibleAssetsDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Schedule of Estimated Useful Lives Definite Lived Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>100340 - Disclosure - Revenue - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureRevenueAdditionalInformationDetails</Role>
      <ShortName>Revenue - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>100350 - Disclosure - Revenue - Additional Information 1 (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureRevenueAdditionalInformation1Details</Role>
      <ShortName>Revenue - Additional Information 1 (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>100360 - Disclosure - Revenue - Summary of Net Revenue Disaggregated by Geographical Area and Product Category (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureRevenueSummaryOfNetRevenueDisaggregatedByGeographicalAreaAndProductCategoryDetails</Role>
      <ShortName>Revenue - Summary of Net Revenue Disaggregated by Geographical Area and Product Category (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>100370 - Disclosure - Concentrations, Risks and Uncertainties - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureConcentrationsRisksAndUncertaintiesAdditionalInformationDetails</Role>
      <ShortName>Concentrations, Risks and Uncertainties - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>100380 - Disclosure - Inventories - Summary of Significant Components of Inventory (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureInventoriesSummaryOfSignificantComponentsOfInventoryDetails</Role>
      <ShortName>Inventories - Summary of Significant Components of Inventory (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>100390 - Disclosure - Property and Equipment, Net - Schedule of Property and Equipment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosurePropertyAndEquipmentNetScheduleOfPropertyAndEquipmentDetails</Role>
      <ShortName>Property and Equipment, Net - Schedule of Property and Equipment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>100400 - Disclosure - Property and Equipment, Net - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosurePropertyAndEquipmentNetAdditionalInformationDetails</Role>
      <ShortName>Property and Equipment, Net - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>100410 - Disclosure - Goodwill and Intangible Assets - Summary of Carrying Amount of Goodwill (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsSummaryOfCarryingAmountOfGoodwillDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Summary of Carrying Amount of Goodwill (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>100420 - Disclosure - Goodwill and Intangible Assets - Schedule of Gross Carrying Amount, Accumulated Amortization and Net Book Value of Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsScheduleOfGrossCarryingAmountAccumulatedAmortizationAndNetBookValueOfIntangibleAssetsDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Schedule of Gross Carrying Amount, Accumulated Amortization and Net Book Value of Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>100430 - Disclosure - Goodwill and Intangible Assets - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsAdditionalInformationDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>100440 - Disclosure - Goodwill and Intangible Assets - Schedule of Estimated Annual Amortization Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsScheduleOfEstimatedAnnualAmortizationExpenseDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Schedule of Estimated Annual Amortization Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>100450 - Disclosure - Lines of Credit - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureLinesOfCreditAdditionalInformationDetails</Role>
      <ShortName>Lines of Credit - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>100460 - Disclosure - Long-Term Debt - Schedule of Long-Term Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureLongTermDebtScheduleOfLongTermDebtDetails</Role>
      <ShortName>Long-Term Debt - Schedule of Long-Term Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>100480 - Disclosure - Long-Term Debt - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureLongTermDebtAdditionalInformationDetails</Role>
      <ShortName>Long-Term Debt - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>100490 - Disclosure - Commitments and Contingencies - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformationDetails</Role>
      <ShortName>Commitments and Contingencies - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>100500 - Disclosure - Commitments and Contingencies - Schedule of Future Minimum Purchases for Maintain Exclusive Rights (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureCommitmentsAndContingenciesScheduleOfFutureMinimumPurchasesForMaintainExclusiveRightsDetails</Role>
      <ShortName>Commitments and Contingencies - Schedule of Future Minimum Purchases for Maintain Exclusive Rights (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>100510 - Disclosure - Stock Compensation - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureStockCompensationAdditionalInformationDetails</Role>
      <ShortName>Stock Compensation - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>100520 - Disclosure - Stock Compensation - Summary of Restricted Stock Activity for the Plans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureStockCompensationSummaryOfRestrictedStockActivityForPlansDetails</Role>
      <ShortName>Stock Compensation - Summary of Restricted Stock Activity for the Plans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>100530 - Disclosure - Provision for Income Taxes - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureProvisionForIncomeTaxesAdditionalInformationDetails</Role>
      <ShortName>Provision for Income Taxes - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>100540 - Disclosure - Related Party Transactions - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureRelatedPartyTransactionsAdditionalInformationDetails</Role>
      <ShortName>Related Party Transactions - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>100550 - Disclosure - Segment Information - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureSegmentInformationAdditionalInformationDetails</Role>
      <ShortName>Segment Information - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>100560 - Disclosure - Segment Information - Performance of Segment based upon Revenues and Operating Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureSegmentInformationPerformanceOfSegmentBasedUponRevenuesAndOperatingIncomeDetails</Role>
      <ShortName>Segment Information - Performance of Segment based upon Revenues and Operating Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="ck1723866-10q_20210331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>100570 - Disclosure - Segment Information - Summary of Segment Assets to Consolidated (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.selectinteriorconcepts.com/20210331/taxonomy/role/DisclosureSegmentInformationSummaryOfSegmentAssetsToConsolidatedDetails</Role>
      <ShortName>Segment Information - Summary of Segment Assets to Consolidated (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</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" original="ck1723866-10q_20210331.htm">ck1723866-10q_20210331.htm</File>
    <File>ck1723866-20210331.xsd</File>
    <File>ck1723866-20210331_cal.xml</File>
    <File>ck1723866-20210331_def.xml</File>
    <File>ck1723866-20210331_lab.xml</File>
    <File>ck1723866-20210331_pre.xml</File>
    <File>ck1723866-ex101_40.htm</File>
    <File>ck1723866-ex311_11.htm</File>
    <File>ck1723866-ex312_12.htm</File>
    <File>ck1723866-ex321_8.htm</File>
    <File>ck1723866-ex322_10.htm</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2020-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/country/2020-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/srt/2020-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/us-gaap/2020-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
