<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.19.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>87</ContextCount>
  <ElementCount>236</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>36</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>6</UnitCount>
  <MyReports>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0001001 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/DocumentandEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001002 - Statement - Condensed Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/CondensedConsolidatedBalanceSheets</Role>
      <ShortName>Condensed Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1002003 - Statement - Condensed Consolidated Balance Sheets (Parentheticals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/CondensedConsolidatedBalanceSheetsParentheticals</Role>
      <ShortName>Condensed Consolidated Balance Sheets (Parentheticals)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1003004 - Statement - Condensed Consolidated Income Statements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/CondensedConsolidatedIncomeStatements</Role>
      <ShortName>Condensed Consolidated Income Statements</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1004005 - Statement - Condensed Consolidated Statements of Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/CondensedConsolidatedStatementsofStockholdersEquity</Role>
      <ShortName>Condensed Consolidated Statements of Stockholders' Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1005006 - Statement - Condensed Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/CondensedConsolidatedStatementsofCashFlows</Role>
      <ShortName>Condensed Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>2101101 - Disclosure - Basis of Presentation and Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/BasisofPresentationandSummaryofSignificantAccountingPolicies</Role>
      <ShortName>Basis of Presentation and Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>2108102 - Disclosure - Stock-Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/StockBasedCompensation</Role>
      <ShortName>Stock-Based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2114103 - Disclosure - Inventory</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/Inventory</Role>
      <ShortName>Inventory</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2117104 - Disclosure - Deferred Compensation Plans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/DeferredCompensationPlans</Role>
      <ShortName>Deferred Compensation Plans</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2119105 - Disclosure - Credit Facility</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/CreditFacility</Role>
      <ShortName>Credit Facility</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2121106 - Disclosure - Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/Leases</Role>
      <ShortName>Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2128107 - Disclosure - Earnings per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/EarningsperShare</Role>
      <ShortName>Earnings per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2131108 - Disclosure - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/SegmentInformation</Role>
      <ShortName>Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2134109 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/CommitmentsandContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2136110 - Disclosure - Related Party</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/RelatedParty</Role>
      <ShortName>Related Party</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2202201 - Disclosure - Basis of Presentation and Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/BasisofPresentationandSummaryofSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Basis of Presentation and Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/BasisofPresentationandSummaryofSignificantAccountingPolicies</ParentRole>
      <Position>17</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2303301 - Disclosure - Basis of Presentation and Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/BasisofPresentationandSummaryofSignificantAccountingPoliciesTables</Role>
      <ShortName>Basis of Presentation and Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/BasisofPresentationandSummaryofSignificantAccountingPolicies</ParentRole>
      <Position>18</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2309302 - Disclosure - Stock-Based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/StockBasedCompensationTables</Role>
      <ShortName>Stock-Based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/StockBasedCompensation</ParentRole>
      <Position>19</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2315303 - Disclosure - Inventory (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/InventoryTables</Role>
      <ShortName>Inventory (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/Inventory</ParentRole>
      <Position>20</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2322304 - Disclosure - Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/LeasesTables</Role>
      <ShortName>Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/Leases</ParentRole>
      <Position>21</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2329305 - Disclosure - Earnings per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/EarningsperShareTables</Role>
      <ShortName>Earnings per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/EarningsperShare</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2332306 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/SegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/SegmentInformation</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2404401 - Disclosure - Basis of Presentation and Summary of Significant Accounting Policies (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/BasisofPresentationandSummaryofSignificantAccountingPoliciesNarrativeDetails</Role>
      <ShortName>Basis of Presentation and Summary of Significant Accounting Policies (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/BasisofPresentationandSummaryofSignificantAccountingPoliciesTables</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2405402 - Disclosure - Basis of Presentation and Summary of Significant Accounting Policies (Disaggregation of Revenue) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/BasisofPresentationandSummaryofSignificantAccountingPoliciesDisaggregationofRevenueDetails</Role>
      <ShortName>Basis of Presentation and Summary of Significant Accounting Policies (Disaggregation of Revenue) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/BasisofPresentationandSummaryofSignificantAccountingPoliciesTables</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2406403 - Disclosure - Basis of Presentation and Summary of Significant Accounting Policies (Contract Balances) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/BasisofPresentationandSummaryofSignificantAccountingPoliciesContractBalancesDetails</Role>
      <ShortName>Basis of Presentation and Summary of Significant Accounting Policies (Contract Balances) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/BasisofPresentationandSummaryofSignificantAccountingPoliciesTables</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2407404 - Disclosure - Basis of Presentation and Summary of Significant Accounting Policies (Cumulative Effect of Changes from Adoption of ASU) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/BasisofPresentationandSummaryofSignificantAccountingPoliciesCumulativeEffectofChangesfromAdoptionofASUDetails</Role>
      <ShortName>Basis of Presentation and Summary of Significant Accounting Policies (Cumulative Effect of Changes from Adoption of ASU) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/BasisofPresentationandSummaryofSignificantAccountingPoliciesTables</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2410405 - Disclosure - Stock-Based Compensation (Stock Option Activity) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/StockBasedCompensationStockOptionActivityDetails</Role>
      <ShortName>Stock-Based Compensation (Stock Option Activity) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/StockBasedCompensationTables</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2411406 - Disclosure - Stock-Based Compensation (Stock Options Outstanding) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/StockBasedCompensationStockOptionsOutstandingDetails</Role>
      <ShortName>Stock-Based Compensation (Stock Options Outstanding) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/StockBasedCompensationTables</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2412407 - Disclosure - Stock-Based Compensation (Summary of Unvested Stock Options) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/StockBasedCompensationSummaryofUnvestedStockOptionsDetails</Role>
      <ShortName>Stock-Based Compensation (Summary of Unvested Stock Options) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/StockBasedCompensationTables</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2413408 - Disclosure - Stock-Based Compensation (Restricted Stock) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/StockBasedCompensationRestrictedStockDetails</Role>
      <ShortName>Stock-Based Compensation (Restricted Stock) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/StockBasedCompensationTables</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2416409 - Disclosure - Inventory (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/InventoryDetails</Role>
      <ShortName>Inventory (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/InventoryTables</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2418410 - Disclosure - Deferred Compensation Plans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/DeferredCompensationPlansDetails</Role>
      <ShortName>Deferred Compensation Plans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/DeferredCompensationPlans</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2420411 - Disclosure - Credit Facility (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/CreditFacilityDetails</Role>
      <ShortName>Credit Facility (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/CreditFacility</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2423412 - Disclosure - Leases (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/LeasesNarrativeDetails</Role>
      <ShortName>Leases (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/LeasesTables</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2424413 - Disclosure - Leases (Balance Sheet Impact) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/LeasesBalanceSheetImpactDetails</Role>
      <ShortName>Leases (Balance Sheet Impact) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/LeasesTables</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2425414 - Disclosure - Leases (Cash Flow Impact) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/LeasesCashFlowImpactDetails</Role>
      <ShortName>Leases (Cash Flow Impact) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/LeasesTables</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2426415 - Disclosure - Leases (Future Maturities of Lease Liabilities) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/LeasesFutureMaturitiesofLeaseLiabilitiesDetails</Role>
      <ShortName>Leases (Future Maturities of Lease Liabilities) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/LeasesTables</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2427416 - Disclosure - Leases (Future Minimum Obligations Under Lease Commitments) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/LeasesFutureMinimumObligationsUnderLeaseCommitmentsDetails</Role>
      <ShortName>Leases (Future Minimum Obligations Under Lease Commitments) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/LeasesTables</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2430417 - Disclosure - Earnings per Share (Basic and Diluted) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/EarningsperShareBasicandDilutedDetails</Role>
      <ShortName>Earnings per Share (Basic and Diluted) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/EarningsperShareTables</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2433418 - Disclosure - Segment Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/SegmentInformationDetails</Role>
      <ShortName>Segment Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/SegmentInformationTables</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2435419 - Disclosure - Commitments and Contingencies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/CommitmentsandContingenciesDetails</Role>
      <ShortName>Commitments and Contingencies (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/CommitmentsandContingencies</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="ngs-20190331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2437420 - Disclosure - Related Party (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://naturalgaservices.com/role/RelatedPartyNarrativeDetails</Role>
      <ShortName>Related Party (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://naturalgaservices.com/role/RelatedParty</ParentRole>
      <Position>43</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="ngs-20190331.htm">ngs-20190331.htm</File>
    <File>ngs-033119xex311.htm</File>
    <File>ngs-033119xex312.htm</File>
    <File>ngs-033119xex321.htm</File>
    <File>ngs-033119xex322.htm</File>
    <File>ngs-20190331.xsd</File>
    <File>ngs-20190331_cal.xml</File>
    <File>ngs-20190331_def.xml</File>
    <File>ngs-20190331_lab.xml</File>
    <File>ngs-20190331_pre.xml</File>
  </InputFiles>
  <SupplementalFiles>
    <File>ngs-20190331_g1.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2018-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/us-gaap/2018-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/srt/2018-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
