<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.20.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>86</ContextCount>
  <ElementCount>273</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>34</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>7</UnitCount>
  <MyReports>
    <Report instance="dnow-10q_20200331.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.distributionnow.com/20200331/taxonomy/role/DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>100010 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/StatementConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>100020 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/StatementConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>100030 - Statement - Consolidated Statements of Operations (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/StatementConsolidatedStatementsOfOperationsUnaudited</Role>
      <ShortName>Consolidated Statements of Operations (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>100040 - Statement - Consolidated Statements of Comprehensive Income (Loss) (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/StatementConsolidatedStatementsOfComprehensiveIncomeLossUnaudited</Role>
      <ShortName>Consolidated Statements of Comprehensive Income (Loss) (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>100050 - Statement - Consolidated Statements of Cash Flows (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/StatementConsolidatedStatementsOfCashFlowsUnaudited</Role>
      <ShortName>Consolidated Statements of Cash Flows (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>100060 - Statement - Consolidated Statements of Stockholders' Equity (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/StatementConsolidatedStatementsOfStockholdersEquityUnaudited</Role>
      <ShortName>Consolidated Statements of Stockholders' Equity (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>100070 - Disclosure - Organization and Basis of Presentation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureOrganizationAndBasisOfPresentation</Role>
      <ShortName>Organization and Basis of Presentation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>100080 - Disclosure - Revenue</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureRevenue</Role>
      <ShortName>Revenue</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>100090 - Disclosure - Receivables, net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureReceivablesNet</Role>
      <ShortName>Receivables, net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>100100 - Disclosure - Asset Impairment</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureAssetImpairment</Role>
      <ShortName>Asset Impairment</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>100110 - Disclosure - Property, Plant and Equipment, net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentNet</Role>
      <ShortName>Property, Plant and Equipment, net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>100120 - Disclosure - Accrued Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureAccruedLiabilities</Role>
      <ShortName>Accrued Liabilities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>100130 - Disclosure - Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureDebt</Role>
      <ShortName>Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>100140 - Disclosure - Accumulated Other Comprehensive Income (Loss)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureAccumulatedOtherComprehensiveIncomeLoss</Role>
      <ShortName>Accumulated Other Comprehensive Income (Loss)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>100150 - Disclosure - Business Segments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureBusinessSegments</Role>
      <ShortName>Business Segments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>100160 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureIncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>100170 - Disclosure - Earnings (Loss) Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureEarningsLossPerShare</Role>
      <ShortName>Earnings (Loss) Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>100180 - Disclosure - Stock-based Compensation and Outstanding Awards</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAndOutstandingAwards</Role>
      <ShortName>Stock-based Compensation and Outstanding Awards</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>100190 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>100200 - Disclosure - Derivative Financial Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstruments</Role>
      <ShortName>Derivative Financial Instruments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>100210 - Disclosure - Business Divestiture</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureBusinessDivestiture</Role>
      <ShortName>Business Divestiture</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>100220 - Disclosure - Organization and Basis of Presentation (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureOrganizationAndBasisOfPresentationPolicies</Role>
      <ShortName>Organization and Basis of Presentation (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>100230 - Disclosure - Receivables, net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureReceivablesNetTables</Role>
      <ShortName>Receivables, net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureReceivablesNet</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>100240 - Disclosure - Asset Impairment (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureAssetImpairmentTables</Role>
      <ShortName>Asset Impairment (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureAssetImpairment</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>100250 - Disclosure - Property, Plant and Equipment, net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentNetTables</Role>
      <ShortName>Property, Plant and Equipment, net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.distributionnow.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentNet</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>100260 - Disclosure - Accrued Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureAccruedLiabilitiesTables</Role>
      <ShortName>Accrued Liabilities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureAccruedLiabilities</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>100270 - Disclosure - Accumulated Other Comprehensive Income (Loss) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureAccumulatedOtherComprehensiveIncomeLossTables</Role>
      <ShortName>Accumulated Other Comprehensive Income (Loss) (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureAccumulatedOtherComprehensiveIncomeLoss</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>100280 - Disclosure - Business Segments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureBusinessSegmentsTables</Role>
      <ShortName>Business Segments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureBusinessSegments</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>100290 - Disclosure - Earnings (Loss) Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureEarningsLossPerShareTables</Role>
      <ShortName>Earnings (Loss) Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureEarningsLossPerShare</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>100300 - Disclosure - Organization and Basis of Presentation - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureOrganizationAndBasisOfPresentationAdditionalInformationDetail</Role>
      <ShortName>Organization and Basis of Presentation - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>100310 - Disclosure - Revenue - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureRevenueAdditionalInformationDetail</Role>
      <ShortName>Revenue - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>100320 - Disclosure - Receivables, net - Rollforward of Allowance for Doubtful Accounts (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureReceivablesNetRollforwardOfAllowanceForDoubtfulAccountsDetail</Role>
      <ShortName>Receivables, net - Rollforward of Allowance for Doubtful Accounts (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>100330 - Disclosure - Property, Plant and Equipment, net - Summary of Property, Plant and Equipment (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentNetSummaryOfPropertyPlantAndEquipmentDetail</Role>
      <ShortName>Property, Plant and Equipment, net - Summary of Property, Plant and Equipment (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>100340 - Disclosure - Property, Plant and Equipment, net - Summary of Property, Plant and Equipment (Parenthetical) (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosurePropertyPlantAndEquipmentNetSummaryOfPropertyPlantAndEquipmentParentheticalDetail</Role>
      <ShortName>Property, Plant and Equipment, net - Summary of Property, Plant and Equipment (Parenthetical) (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>100350 - Disclosure - Asset Impairment - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureAssetImpairmentAdditionalInformationDetail</Role>
      <ShortName>Asset Impairment - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>100360 - Disclosure - Asset Impairment - Summary of Goodwill by Reportable Segment (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureAssetImpairmentSummaryOfGoodwillByReportableSegmentDetail</Role>
      <ShortName>Asset Impairment - Summary of Goodwill by Reportable Segment (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>100370 - Disclosure - Asset Impairment - Summary of Goodwill by Reportable Segment (Parenthetical) (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureAssetImpairmentSummaryOfGoodwillByReportableSegmentParentheticalDetail</Role>
      <ShortName>Asset Impairment - Summary of Goodwill by Reportable Segment (Parenthetical) (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>100380 - Disclosure - Asset Impairment - Summary of Impairment of Long-lived Assets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureAssetImpairmentSummaryOfImpairmentOfLongLivedAssetsDetail</Role>
      <ShortName>Asset Impairment - Summary of Impairment of Long-lived Assets (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>100390 - Disclosure - Accrued Liabilities - Summary of Accrued Liabilities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureAccruedLiabilitiesSummaryOfAccruedLiabilitiesDetail</Role>
      <ShortName>Accrued Liabilities - Summary of Accrued Liabilities (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>100400 - Disclosure - Debt - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureDebtAdditionalInformationDetail</Role>
      <ShortName>Debt - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>100410 - Disclosure - Accumulated Other Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Income (Loss) (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureAccumulatedOtherComprehensiveIncomeLossComponentsOfAccumulatedOtherComprehensiveIncomeLossDetail</Role>
      <ShortName>Accumulated Other Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Income (Loss) (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureAccumulatedOtherComprehensiveIncomeLossTables</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>100420 - Disclosure - Business Segments - Summary of Operating Results by Reportable Segment (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureBusinessSegmentsSummaryOfOperatingResultsByReportableSegmentDetail</Role>
      <ShortName>Business Segments - Summary of Operating Results by Reportable Segment (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>100430 - Disclosure - Income Taxes - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetail</Role>
      <ShortName>Income Taxes - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>100440 - Disclosure - Earnings (Loss) Per Share - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureEarningsLossPerShareAdditionalInformationDetail</Role>
      <ShortName>Earnings (Loss) Per Share - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureEarningsLossPerShareTables</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>100450 - Disclosure - Earnings (Loss) Per Share - Computation of Basic and Diluted Earnings (Loss) Per Share (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureEarningsLossPerShareComputationOfBasicAndDilutedEarningsLossPerShareDetail</Role>
      <ShortName>Earnings (Loss) Per Share - Computation of Basic and Diluted Earnings (Loss) Per Share (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureEarningsLossPerShareTables</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>100460 - Disclosure - Stock-based Compensation and Outstanding Awards - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureStockBasedCompensationAndOutstandingAwardsAdditionalInformationDetail</Role>
      <ShortName>Stock-based Compensation and Outstanding Awards - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>100470 - Disclosure - Commitments and Contingencies - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformationDetail</Role>
      <ShortName>Commitments and Contingencies - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>100480 - Disclosure - Derivative Financial Instruments - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureDerivativeFinancialInstrumentsAdditionalInformationDetail</Role>
      <ShortName>Derivative Financial Instruments - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="dnow-10q_20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>100490 - Disclosure - Business Divestiture - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.distributionnow.com/20200331/taxonomy/role/DisclosureBusinessDivestitureAdditionalInformationDetail</Role>
      <ShortName>Business Divestiture - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</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="dnow-10q_20200331.htm">dnow-10q_20200331.htm</File>
    <File>dnow-20200331.xsd</File>
    <File>dnow-20200331_cal.xml</File>
    <File>dnow-20200331_def.xml</File>
    <File>dnow-20200331_lab.xml</File>
    <File>dnow-20200331_pre.xml</File>
    <File>dnow-ex311_8.htm</File>
    <File>dnow-ex312_6.htm</File>
    <File>dnow-ex321_7.htm</File>
    <File>dnow-ex322_9.htm</File>
  </InputFiles>
  <SupplementalFiles>
    <File>gpgshv0rxupz000001.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy>http://fasb.org/us-gaap/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/srt/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/country/2017-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/stpr/2018-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
