<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.19.2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>606</ContextCount>
  <ElementCount>798</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>177</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>17</UnitCount>
  <MyReports>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0001000 - Document - Document And Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/DocumentAndEntityInformation</Role>
      <ShortName>Document And Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001000 - Statement - Consolidated Statements Of Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/ConsolidatedStatementsOfOperations</Role>
      <ShortName>Consolidated Statements Of Operations</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1002000 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/ConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1002501 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/ConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1003000 - Statement - Consolidated Statements Of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/ConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Consolidated Statements Of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1004000 - Statement - Consolidated Statement Of Changes In Stockholders' Equity (Successor)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/ConsolidatedStatementOfChangesInStockholdersEquitySuccessor</Role>
      <ShortName>Consolidated Statement Of Changes In Stockholders' Equity (Successor)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>1005000 - Statement - Consolidated Statements Of Changes In Partners' Capital</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/ConsolidatedStatementsOfChangesInPartnersCapital</Role>
      <ShortName>Consolidated Statements Of Changes In Partners' Capital</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>2101100 - Disclosure - Description Of Business</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/DescriptionOfBusiness</Role>
      <ShortName>Description Of Business</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2102100 - Disclosure - Summary Of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary Of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2103100 - Disclosure - Adoption of New Standard - Revenue from Contracts with Customers</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/AdoptionOfNewStandardRevenueFromContractsWithCustomers</Role>
      <ShortName>Adoption of New Standard - Revenue from Contracts with Customers</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2104100 - Disclosure - Impairment of Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/ImpairmentOfAssets</Role>
      <ShortName>Impairment of Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2105100 - Disclosure - Receivables</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/Receivables</Role>
      <ShortName>Receivables</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2106100 - Disclosure - Earnings Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/EarningsPerShare</Role>
      <ShortName>Earnings Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2106100 - Disclosure - Supplemental Cash Flow Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SupplementalCashFlowInformation</Role>
      <ShortName>Supplemental Cash Flow Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2107100 - Disclosure - Significant Acquisitions and Divestitures</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SignificantAcquisitionsAndDivestitures</Role>
      <ShortName>Significant Acquisitions and Divestitures</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2108100 - Disclosure - Property, Plant And Equipment</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/PropertyPlantAndEquipment</Role>
      <ShortName>Property, Plant And Equipment</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2109100 - Disclosure - Discontinued Operations (Predecessor)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/DiscontinuedOperationsPredecessor</Role>
      <ShortName>Discontinued Operations (Predecessor)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2110100 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/FairValueMeasurements</Role>
      <ShortName>Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2111100 - Disclosure - Derivatives</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/Derivatives</Role>
      <ShortName>Derivatives</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2112100 - Disclosure - Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/IntangibleAssets</Role>
      <ShortName>Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2113100 - Disclosure - Equity Method Investment</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/EquityMethodInvestment</Role>
      <ShortName>Equity Method Investment</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2114100 - Disclosure - Asset Retirement Obligations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/AssetRetirementObligations</Role>
      <ShortName>Asset Retirement Obligations</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2115100 - Disclosure - Long Term Debt, Net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/LongTermDebtNet</Role>
      <ShortName>Long Term Debt, Net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2116100 - Disclosure - Accounts Payable And Accrued Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/AccountsPayableAndAccruedLiabilities</Role>
      <ShortName>Accounts Payable And Accrued Liabilities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2117100 - Disclosure - Commitments And Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/CommitmentsAndContingencies</Role>
      <ShortName>Commitments And Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2118100 - Disclosure - Employee Benefit Plans Employee Benefit Plans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/EmployeeBenefitPlansEmployeeBenefitPlans</Role>
      <ShortName>Employee Benefit Plans Employee Benefit Plans</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2119100 - Disclosure - Significant Concentrations, Risks And Uncertainties</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SignificantConcentrationsRisksAndUncertainties</Role>
      <ShortName>Significant Concentrations, Risks And Uncertainties</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2120100 - Disclosure - Stockholders' Equity And Partners' Capital</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/StockholdersEquityAndPartnersCapital</Role>
      <ShortName>Stockholders' Equity And Partners' Capital</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2121100 - Disclosure - Equity-Based Compensation (Successor)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/EquityBasedCompensationSuccessor</Role>
      <ShortName>Equity-Based Compensation (Successor)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2122100 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2123100 - Disclosure - Related Party Transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/RelatedPartyTransactions</Role>
      <ShortName>Related Party Transactions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2125100 - Disclosure - Business Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/BusinessSegmentInformation</Role>
      <ShortName>Business Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2126100 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2127100 - Disclosure - Supplemental Quarterly Information (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SupplementalQuarterlyInformationUnaudited</Role>
      <ShortName>Supplemental Quarterly Information (Unaudited)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2129100 - Disclosure - Supplemental Oil and Natural Gas Disclosures Supplemental Oil and Natural Gas Disclosures</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SupplementalOilAndNaturalGasDisclosuresSupplementalOilAndNaturalGasDisclosures</Role>
      <ShortName>Supplemental Oil and Natural Gas Disclosures Supplemental Oil and Natural Gas Disclosures</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2202201 - Disclosure - Summary Of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary Of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2303301 - Disclosure - Adoption of New Standard - Revenue from Contracts with Customers (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/AdoptionOfNewStandardRevenueFromContractsWithCustomersTables</Role>
      <ShortName>Adoption of New Standard - Revenue from Contracts with Customers (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/AdoptionOfNewStandardRevenueFromContractsWithCustomers</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2304301 - Disclosure - Impairment of Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/ImpairmentOfAssetsTables</Role>
      <ShortName>Impairment of Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/ImpairmentOfAssets</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2305301 - Disclosure - Receivables (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/ReceivablesTables</Role>
      <ShortName>Receivables (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/Receivables</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2306301 - Disclosure - Earnings Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/EarningsPerShareTables</Role>
      <ShortName>Earnings Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/EarningsPerShare</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2306301 - Disclosure - Supplemental Cash Flow Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SupplementalCashFlowInformationTables</Role>
      <ShortName>Supplemental Cash Flow Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SupplementalCashFlowInformation</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2307301 - Disclosure - Significant Acquisitions and Divestitures (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SignificantAcquisitionsAndDivestituresTables</Role>
      <ShortName>Significant Acquisitions and Divestitures (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SignificantAcquisitionsAndDivestitures</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2308301 - Disclosure - Property, Plant And Equipment (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/PropertyPlantAndEquipmentTables</Role>
      <ShortName>Property, Plant And Equipment (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/PropertyPlantAndEquipment</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>2309301 - Disclosure - Discontinued Operations (Predecessor) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/DiscontinuedOperationsPredecessorTables</Role>
      <ShortName>Discontinued Operations (Predecessor) (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/DiscontinuedOperationsPredecessor</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>2310301 - Disclosure - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/FairValueMeasurementsTables</Role>
      <ShortName>Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/FairValueMeasurements</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>2311301 - Disclosure - Derivatives (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/DerivativesTables</Role>
      <ShortName>Derivatives (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/Derivatives</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>2312301 - Disclosure - Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/IntangibleAssetsTables</Role>
      <ShortName>Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/IntangibleAssets</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>2313301 - Disclosure - Equity Method Investment (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/EquityMethodInvestmentTables</Role>
      <ShortName>Equity Method Investment (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/EquityMethodInvestment</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>2314301 - Disclosure - Asset Retirement Obligations (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/AssetRetirementObligationsTables</Role>
      <ShortName>Asset Retirement Obligations (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/AssetRetirementObligations</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>2315301 - Disclosure - Long Term Debt, Net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/LongTermDebtNetTables</Role>
      <ShortName>Long Term Debt, Net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/LongTermDebtNet</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>2316301 - Disclosure - Accounts Payable And Accrued Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/AccountsPayableAndAccruedLiabilitiesTables</Role>
      <ShortName>Accounts Payable And Accrued Liabilities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/AccountsPayableAndAccruedLiabilities</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>2317301 - Disclosure - Commitments And Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/CommitmentsAndContingenciesTables</Role>
      <ShortName>Commitments And Contingencies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/CommitmentsAndContingencies</ParentRole>
      <Position>52</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>2321301 - Disclosure - Equity-Based Compensation (Successor) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/EquityBasedCompensationSuccessorTables</Role>
      <ShortName>Equity-Based Compensation (Successor) (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/EquityBasedCompensationSuccessor</ParentRole>
      <Position>53</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>2322301 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/IncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/IncomeTaxes</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>2325301 - Disclosure - Business Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/BusinessSegmentInformationTables</Role>
      <ShortName>Business Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/BusinessSegmentInformation</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>2327301 - Disclosure - Supplemental Quarterly Information (Unaudited) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SupplementalQuarterlyInformationUnauditedTables</Role>
      <ShortName>Supplemental Quarterly Information (Unaudited) (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SupplementalQuarterlyInformationUnaudited</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>2329301 - Disclosure - Supplemental Oil and Natural Gas Disclosures (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SupplementalOilAndNaturalGasDisclosuresTables</Role>
      <ShortName>Supplemental Oil and Natural Gas Disclosures (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SupplementalOilAndNaturalGasDisclosuresSupplementalOilAndNaturalGasDisclosures</ParentRole>
      <Position>57</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>2401401 - Disclosure - Description Of Business (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/DescriptionOfBusinessDetails</Role>
      <ShortName>Description Of Business (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/DescriptionOfBusiness</ParentRole>
      <Position>58</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>2402402 - Disclosure - Summary Of Significant Accounting Policies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SummaryOfSignificantAccountingPoliciesDetails</Role>
      <ShortName>Summary Of Significant Accounting Policies (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SummaryOfSignificantAccountingPoliciesPolicies</ParentRole>
      <Position>59</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>2403402 - Disclosure - Adoption of New Standard - Revenue from Contracts with Customers (Summary of Revenues and Costs) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/AdoptionOfNewStandardRevenueFromContractsWithCustomersSummaryOfRevenuesAndCostsDetails</Role>
      <ShortName>Adoption of New Standard - Revenue from Contracts with Customers (Summary of Revenues and Costs) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/AdoptionOfNewStandardRevenueFromContractsWithCustomersTables</ParentRole>
      <Position>60</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>2403403 - Disclosure - Adoption of New Standard - Revenue from Contracts with Customers (Summary of Revenues and Costs with Impact of ASC 606) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/AdoptionOfNewStandardRevenueFromContractsWithCustomersSummaryOfRevenuesAndCostsWithImpactOfAsc606Details</Role>
      <ShortName>Adoption of New Standard - Revenue from Contracts with Customers (Summary of Revenues and Costs with Impact of ASC 606) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/AdoptionOfNewStandardRevenueFromContractsWithCustomersTables</ParentRole>
      <Position>61</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>2403404 - Disclosure - Adoption of New Standard - Revenue from Contracts with Customers (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/AdoptionOfNewStandardRevenueFromContractsWithCustomersNarrativeDetails</Role>
      <ShortName>Adoption of New Standard - Revenue from Contracts with Customers (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/AdoptionOfNewStandardRevenueFromContractsWithCustomersTables</ParentRole>
      <Position>62</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>2404402 - Disclosure - Impairment of Assets (Schedule of Impairments) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/ImpairmentOfAssetsScheduleOfImpairmentsDetails</Role>
      <ShortName>Impairment of Assets (Schedule of Impairments) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/ImpairmentOfAssetsTables</ParentRole>
      <Position>63</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>2404403 - Disclosure - Impairment of Assets (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/ImpairmentOfAssetsNarrativeDetails</Role>
      <ShortName>Impairment of Assets (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/ImpairmentOfAssetsTables</ParentRole>
      <Position>64</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>2405402 - Disclosure - Receivables (Schedule of Accounts Receivable) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/ReceivablesScheduleOfAccountsReceivableDetails</Role>
      <ShortName>Receivables (Schedule of Accounts Receivable) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/ReceivablesTables</ParentRole>
      <Position>65</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>2405403 - Disclosure - Receivables (Allowance for doubtful accounts) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/ReceivablesAllowanceForDoubtfulAccountsDetails</Role>
      <ShortName>Receivables (Allowance for doubtful accounts) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/ReceivablesTables</ParentRole>
      <Position>66</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>2406402 - Disclosure - Earnings Per Share (Net Loss Attributable to Common Stockholders) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/EarningsPerShareNetLossAttributableToCommonStockholdersDetails</Role>
      <ShortName>Earnings Per Share (Net Loss Attributable to Common Stockholders) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/EarningsPerShareTables</ParentRole>
      <Position>67</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>2406402 - Disclosure - Supplemental Cash Flow Information (Supplemental Disclosures To The Consolidated Statements Of Cash Flows) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SupplementalCashFlowInformationSupplementalDisclosuresToConsolidatedStatementsOfCashFlowsDetails</Role>
      <ShortName>Supplemental Cash Flow Information (Supplemental Disclosures To The Consolidated Statements Of Cash Flows) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SupplementalCashFlowInformationTables</ParentRole>
      <Position>68</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>2406403 - Disclosure - Earnings Per Share (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/EarningsPerShareNarrativeDetails</Role>
      <ShortName>Earnings Per Share (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/EarningsPerShareTables</ParentRole>
      <Position>69</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>2406403 - Disclosure - Supplemental Cash Flow Information (Reconciliation Of Cash, Cash Equivalents And Restricted Cash) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SupplementalCashFlowInformationReconciliationOfCashCashEquivalentsAndRestrictedCashDetails</Role>
      <ShortName>Supplemental Cash Flow Information (Reconciliation Of Cash, Cash Equivalents And Restricted Cash) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SupplementalCashFlowInformationTables</ParentRole>
      <Position>70</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>2407402 - Disclosure - Significant Acquisitions and Divestitures (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SignificantAcquisitionsAndDivestituresNarrativeDetails</Role>
      <ShortName>Significant Acquisitions and Divestitures (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SignificantAcquisitionsAndDivestituresTables</ParentRole>
      <Position>71</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>2407403 - Disclosure - Significant Acquisitions and Divestitures (Earn-Out Consideration) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SignificantAcquisitionsAndDivestituresEarnOutConsiderationDetails</Role>
      <ShortName>Significant Acquisitions and Divestitures (Earn-Out Consideration) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SignificantAcquisitionsAndDivestituresTables</ParentRole>
      <Position>72</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>2407404 - Disclosure - Significant Acquisitions and Divestitures (Purchase Consideration) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SignificantAcquisitionsAndDivestituresPurchaseConsiderationDetails</Role>
      <ShortName>Significant Acquisitions and Divestitures (Purchase Consideration) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SignificantAcquisitionsAndDivestituresTables</ParentRole>
      <Position>73</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>2407405 - Disclosure - Significant Acquisitions and Divestitures (Allocation Of Purchase Consideration) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SignificantAcquisitionsAndDivestituresAllocationOfPurchaseConsiderationDetails</Role>
      <ShortName>Significant Acquisitions and Divestitures (Allocation Of Purchase Consideration) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SignificantAcquisitionsAndDivestituresTables</ParentRole>
      <Position>74</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>2407406 - Disclosure - Significant Acquisitions and Divestitures Significant Acquisitions and Divestitures (Summary Of Consideration Paid And Preliminary Allocation Of Purchase Prices) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SignificantAcquisitionsAndDivestituresSignificantAcquisitionsAndDivestituresSummaryOfConsiderationPaidAndPreliminaryAllocationOfPurchasePricesDetails</Role>
      <ShortName>Significant Acquisitions and Divestitures Significant Acquisitions and Divestitures (Summary Of Consideration Paid And Preliminary Allocation Of Purchase Prices) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>2407407 - Disclosure - Significant Acquisitions and Divestitures (Summary Of Pro Forma Information) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SignificantAcquisitionsAndDivestituresSummaryOfProFormaInformationDetails</Role>
      <ShortName>Significant Acquisitions and Divestitures (Summary Of Pro Forma Information) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SignificantAcquisitionsAndDivestituresTables</ParentRole>
      <Position>76</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>2408402 - Disclosure - Property, Plant And Equipment (Summary Of Property And Equipment) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/PropertyPlantAndEquipmentSummaryOfPropertyAndEquipmentDetails</Role>
      <ShortName>Property, Plant And Equipment (Summary Of Property And Equipment) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/PropertyPlantAndEquipmentTables</ParentRole>
      <Position>77</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>2408403 - Disclosure - Property, Plant And Equipment (Depreciation and Depletion) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/PropertyPlantAndEquipmentDepreciationAndDepletionDetails</Role>
      <ShortName>Property, Plant And Equipment (Depreciation and Depletion) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/PropertyPlantAndEquipmentTables</ParentRole>
      <Position>78</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>2408404 - Disclosure - Property, Plant And Equipment (Sale of Produced Water Assets) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/PropertyPlantAndEquipmentSaleOfProducedWaterAssetsDetails</Role>
      <ShortName>Property, Plant And Equipment (Sale of Produced Water Assets) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/PropertyPlantAndEquipmentTables</ParentRole>
      <Position>79</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>2409402 - Disclosure - Discontinued Operations (Predecessor) (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/DiscontinuedOperationsPredecessorNarrativeDetails</Role>
      <ShortName>Discontinued Operations (Predecessor) (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/DiscontinuedOperationsPredecessorTables</ParentRole>
      <Position>80</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>2409403 - Disclosure - Discontinued Operations (Predecessor) (Schedule Of Assets And Liabilities Reclassified In Discontinued Operation) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/DiscontinuedOperationsPredecessorScheduleOfAssetsAndLiabilitiesReclassifiedInDiscontinuedOperationDetails</Role>
      <ShortName>Discontinued Operations (Predecessor) (Schedule Of Assets And Liabilities Reclassified In Discontinued Operation) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/DiscontinuedOperationsPredecessorTables</ParentRole>
      <Position>81</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>2409404 - Disclosure - Discontinued Operations (Predecessor) (Schedule Of Operations And Other Items Reclassified In Discontinued Operations) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/DiscontinuedOperationsPredecessorScheduleOfOperationsAndOtherItemsReclassifiedInDiscontinuedOperationsDetails</Role>
      <ShortName>Discontinued Operations (Predecessor) (Schedule Of Operations And Other Items Reclassified In Discontinued Operations) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/DiscontinuedOperationsPredecessorTables</ParentRole>
      <Position>82</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>2409405 - Disclosure - Discontinued Operations (Predecessor) (Total Operating And Investing Cash Flows Of Discontinued Operations) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/DiscontinuedOperationsPredecessorTotalOperatingAndInvestingCashFlowsOfDiscontinuedOperationsDetails</Role>
      <ShortName>Discontinued Operations (Predecessor) (Total Operating And Investing Cash Flows Of Discontinued Operations) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/DiscontinuedOperationsPredecessorTables</ParentRole>
      <Position>83</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>2410402 - Disclosure - Fair Value Measurements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/FairValueMeasurementsDetails</Role>
      <ShortName>Fair Value Measurements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/FairValueMeasurementsTables</ParentRole>
      <Position>84</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>2411402 - Disclosure - Derivatives (Fair Values Of Derivative Contracts) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/DerivativesFairValuesOfDerivativeContractsDetails</Role>
      <ShortName>Derivatives (Fair Values Of Derivative Contracts) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/DerivativesTables</ParentRole>
      <Position>85</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>2411403 - Disclosure - Derivatives (Effect Of Derivative Instruments In The Consolidated Statements Of Operations) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/DerivativesEffectOfDerivativeInstrumentsInConsolidatedStatementsOfOperationsDetails</Role>
      <ShortName>Derivatives (Effect Of Derivative Instruments In The Consolidated Statements Of Operations) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/DerivativesTables</ParentRole>
      <Position>86</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>2411404 - Disclosure - Derivatives (Oil Derivative Contracts) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/DerivativesOilDerivativeContractsDetails</Role>
      <ShortName>Derivatives (Oil Derivative Contracts) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/DerivativesTables</ParentRole>
      <Position>87</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>2411405 - Disclosure - Derivatives (Natural Gas Derivative Contracts) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/DerivativesNaturalGasDerivativeContractsDetails</Role>
      <ShortName>Derivatives (Natural Gas Derivative Contracts) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/DerivativesTables</ParentRole>
      <Position>88</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>2411406 - Disclosure - Derivatives (Natural Gas Basis Swap Derivative Contracts) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/DerivativesNaturalGasBasisSwapDerivativeContractsDetails</Role>
      <ShortName>Derivatives (Natural Gas Basis Swap Derivative Contracts) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/DerivativesTables</ParentRole>
      <Position>89</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>2411407 - Disclosure - Derivatives (Additional Information) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/DerivativesAdditionalInformationDetails</Role>
      <ShortName>Derivatives (Additional Information) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/DerivativesTables</ParentRole>
      <Position>90</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>2412402 - Disclosure - Intangible Assets (Schedule Of Finite-Lived Customer Relationships) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/IntangibleAssetsScheduleOfFiniteLivedCustomerRelationshipsDetails</Role>
      <ShortName>Intangible Assets (Schedule Of Finite-Lived Customer Relationships) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/IntangibleAssetsTables</ParentRole>
      <Position>91</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R92.htm</HtmlFileName>
      <LongName>2412403 - Disclosure - Intangible Assets (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/IntangibleAssetsNarrativeDetails</Role>
      <ShortName>Intangible Assets (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/IntangibleAssetsTables</ParentRole>
      <Position>92</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R93.htm</HtmlFileName>
      <LongName>2413402 - Disclosure - Equity Method Investment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/EquityMethodInvestmentDetails</Role>
      <ShortName>Equity Method Investment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/EquityMethodInvestmentTables</ParentRole>
      <Position>93</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R94.htm</HtmlFileName>
      <LongName>2414402 - Disclosure - Asset Retirement Obligations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/AssetRetirementObligationsDetails</Role>
      <ShortName>Asset Retirement Obligations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/AssetRetirementObligationsTables</ParentRole>
      <Position>94</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R95.htm</HtmlFileName>
      <LongName>2415402 - Disclosure - Long Term Debt, Net (Long-Term Debt, Net) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/LongTermDebtNetLongTermDebtNetDetails</Role>
      <ShortName>Long Term Debt, Net (Long-Term Debt, Net) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/LongTermDebtNetTables</ParentRole>
      <Position>95</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R96.htm</HtmlFileName>
      <LongName>2415403 - Disclosure - Long Term Debt, Net (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/LongTermDebtNetNarrativeDetails</Role>
      <ShortName>Long Term Debt, Net (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/LongTermDebtNetTables</ParentRole>
      <Position>96</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R97.htm</HtmlFileName>
      <LongName>2415404 - Disclosure - Long Term Debt, Net (Redemption Prices) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/LongTermDebtNetRedemptionPricesDetails</Role>
      <ShortName>Long Term Debt, Net (Redemption Prices) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/LongTermDebtNetTables</ParentRole>
      <Position>97</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R98.htm</HtmlFileName>
      <LongName>2415405 - Disclosure - Long Term Debt, Net (Summary Of Future Maturities Of Long-Term Debt) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/LongTermDebtNetSummaryOfFutureMaturitiesOfLongTermDebtDetails</Role>
      <ShortName>Long Term Debt, Net (Summary Of Future Maturities Of Long-Term Debt) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/LongTermDebtNetTables</ParentRole>
      <Position>98</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R99.htm</HtmlFileName>
      <LongName>2415406 - Disclosure - Long Term Debt, Net (Deferred Financing Costs) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/LongTermDebtNetDeferredFinancingCostsDetails</Role>
      <ShortName>Long Term Debt, Net (Deferred Financing Costs) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/LongTermDebtNetTables</ParentRole>
      <Position>99</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R100.htm</HtmlFileName>
      <LongName>2416402 - Disclosure - Accounts Payable And Accrued Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/AccountsPayableAndAccruedLiabilitiesDetails</Role>
      <ShortName>Accounts Payable And Accrued Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/AccountsPayableAndAccruedLiabilitiesTables</ParentRole>
      <Position>100</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R101.htm</HtmlFileName>
      <LongName>2417402 - Disclosure - Commitments and Contingencies (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/CommitmentsAndContingenciesNarrativeDetails</Role>
      <ShortName>Commitments and Contingencies (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>101</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R102.htm</HtmlFileName>
      <LongName>2417403 - Disclosure - Commitments And Contingencies (Future Base Rentals For Non-Cancelable Leases) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/CommitmentsAndContingenciesFutureBaseRentalsForNonCancelableLeasesDetails</Role>
      <ShortName>Commitments And Contingencies (Future Base Rentals For Non-Cancelable Leases) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/CommitmentsAndContingenciesTables</ParentRole>
      <Position>102</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R103.htm</HtmlFileName>
      <LongName>2417404 - Disclosure - Commitments And Contingencies (Schedule Of Firm Transportation Contracts) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/CommitmentsAndContingenciesScheduleOfFirmTransportationContractsDetails</Role>
      <ShortName>Commitments And Contingencies (Schedule Of Firm Transportation Contracts) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/CommitmentsAndContingenciesTables</ParentRole>
      <Position>103</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R104.htm</HtmlFileName>
      <LongName>2418401 - Disclosure - Employee Benefit Plans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/EmployeeBenefitPlansDetails</Role>
      <ShortName>Employee Benefit Plans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/EmployeeBenefitPlansEmployeeBenefitPlans</ParentRole>
      <Position>104</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R105.htm</HtmlFileName>
      <LongName>2419401 - Disclosure - Significant Concentrations, Risks And Uncertainties (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SignificantConcentrationsRisksAndUncertaintiesDetails</Role>
      <ShortName>Significant Concentrations, Risks And Uncertainties (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SignificantConcentrationsRisksAndUncertainties</ParentRole>
      <Position>105</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R106.htm</HtmlFileName>
      <LongName>2420401 - Disclosure - Stockholders' Equity And Partners' Capital  (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/StockholdersEquityAndPartnersCapitalDetails</Role>
      <ShortName>Stockholders' Equity And Partners' Capital  (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/StockholdersEquityAndPartnersCapital</ParentRole>
      <Position>106</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R107.htm</HtmlFileName>
      <LongName>2421402 - Disclosure - Equity-Based Compensation (Successor) (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/EquityBasedCompensationSuccessorNarrativeDetails</Role>
      <ShortName>Equity-Based Compensation (Successor) (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/EquityBasedCompensationSuccessorTables</ParentRole>
      <Position>107</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R108.htm</HtmlFileName>
      <LongName>2421403 - Disclosure - Equity-Based Compensation (Successor) (Schedule of Outstanding Stock Options) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/EquityBasedCompensationSuccessorScheduleOfOutstandingStockOptionsDetails</Role>
      <ShortName>Equity-Based Compensation (Successor) (Schedule of Outstanding Stock Options) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/EquityBasedCompensationSuccessorTables</ParentRole>
      <Position>108</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R109.htm</HtmlFileName>
      <LongName>2421404 - Disclosure - Equity-Based Compensation (Successor) (Summary of Assumptions Used to Determine the Fair Value of Options) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/EquityBasedCompensationSuccessorSummaryOfAssumptionsUsedToDetermineFairValueOfOptionsDetails</Role>
      <ShortName>Equity-Based Compensation (Successor) (Summary of Assumptions Used to Determine the Fair Value of Options) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/EquityBasedCompensationSuccessorTables</ParentRole>
      <Position>109</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R110.htm</HtmlFileName>
      <LongName>2421405 - Disclosure - Equity-Based Compensation (Successor) (Schedule of Restricted Stock Awards and PSUs Granted) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/EquityBasedCompensationSuccessorScheduleOfRestrictedStockAwardsAndPsusGrantedDetails</Role>
      <ShortName>Equity-Based Compensation (Successor) (Schedule of Restricted Stock Awards and PSUs Granted) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/EquityBasedCompensationSuccessorTables</ParentRole>
      <Position>110</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R111.htm</HtmlFileName>
      <LongName>2422402 - Disclosure - Income Taxes (Schedule Of Components Of Income Tax Expense (Benefit)) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/IncomeTaxesScheduleOfComponentsOfIncomeTaxExpenseBenefitDetails</Role>
      <ShortName>Income Taxes (Schedule Of Components Of Income Tax Expense (Benefit)) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/IncomeTaxesTables</ParentRole>
      <Position>111</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R112.htm</HtmlFileName>
      <LongName>2422403 - Disclosure - Income Taxes (Income Tax Rate Reconciliation) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/IncomeTaxesIncomeTaxRateReconciliationDetails</Role>
      <ShortName>Income Taxes (Income Tax Rate Reconciliation) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/IncomeTaxesTables</ParentRole>
      <Position>112</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R113.htm</HtmlFileName>
      <LongName>2422404 - Disclosure - Income Taxes (Deferred Tax Assets and Liabilities) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/IncomeTaxesDeferredTaxAssetsAndLiabilitiesDetails</Role>
      <ShortName>Income Taxes (Deferred Tax Assets and Liabilities) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/IncomeTaxesTables</ParentRole>
      <Position>113</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R114.htm</HtmlFileName>
      <LongName>2422406 - Disclosure - Income Taxes (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/IncomeTaxesNarrativeDetails</Role>
      <ShortName>Income Taxes (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/IncomeTaxesTables</ParentRole>
      <Position>114</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R115.htm</HtmlFileName>
      <LongName>2423401 - Disclosure - Related Party Transactions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/RelatedPartyTransactionsDetails</Role>
      <ShortName>Related Party Transactions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/RelatedPartyTransactions</ParentRole>
      <Position>115</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R116.htm</HtmlFileName>
      <LongName>2425402 - Disclosure - Business Segment Information (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/BusinessSegmentInformationNarrativeDetails</Role>
      <ShortName>Business Segment Information (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/BusinessSegmentInformationTables</ParentRole>
      <Position>116</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R117.htm</HtmlFileName>
      <LongName>2425403 - Disclosure - Business Segment Information (Schedule Of Results Of Reportable Segments) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/BusinessSegmentInformationScheduleOfResultsOfReportableSegmentsDetails</Role>
      <ShortName>Business Segment Information (Schedule Of Results Of Reportable Segments) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/BusinessSegmentInformationTables</ParentRole>
      <Position>117</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R118.htm</HtmlFileName>
      <LongName>2425404 - Disclosure - Business Segment Information (Summary Of Assets By Segment) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/BusinessSegmentInformationSummaryOfAssetsBySegmentDetails</Role>
      <ShortName>Business Segment Information (Summary Of Assets By Segment) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/BusinessSegmentInformationTables</ParentRole>
      <Position>118</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R119.htm</HtmlFileName>
      <LongName>2426401 - Disclosure - Subsequent Events (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SubsequentEventsDetails</Role>
      <ShortName>Subsequent Events (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SubsequentEvents</ParentRole>
      <Position>119</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R120.htm</HtmlFileName>
      <LongName>2427402 - Disclosure - Supplemental Quarterly Information (Unaudited) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SupplementalQuarterlyInformationUnauditedDetails</Role>
      <ShortName>Supplemental Quarterly Information (Unaudited) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SupplementalQuarterlyInformationUnauditedTables</ParentRole>
      <Position>120</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R121.htm</HtmlFileName>
      <LongName>2429402 - Disclosure - Supplemental Oil and Natural Gas Disclosures (Estimated Quantities of Proved Reserves) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SupplementalOilAndNaturalGasDisclosuresEstimatedQuantitiesOfProvedReservesDetails</Role>
      <ShortName>Supplemental Oil and Natural Gas Disclosures (Estimated Quantities of Proved Reserves) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SupplementalOilAndNaturalGasDisclosuresTables</ParentRole>
      <Position>121</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R122.htm</HtmlFileName>
      <LongName>2429403 - Disclosure - Supplemental Oil and Natural Gas Disclosures (Results of Operations) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SupplementalOilAndNaturalGasDisclosuresResultsOfOperationsDetails</Role>
      <ShortName>Supplemental Oil and Natural Gas Disclosures (Results of Operations) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SupplementalOilAndNaturalGasDisclosuresTables</ParentRole>
      <Position>122</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R123.htm</HtmlFileName>
      <LongName>2429404 - Disclosure - Supplemental Oil and Natural Gas Disclosures (Capitalized Costs Relating to Oil and Natural Gas Producing Activities) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SupplementalOilAndNaturalGasDisclosuresCapitalizedCostsRelatingToOilAndNaturalGasProducingActivitiesDetails</Role>
      <ShortName>Supplemental Oil and Natural Gas Disclosures (Capitalized Costs Relating to Oil and Natural Gas Producing Activities) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SupplementalOilAndNaturalGasDisclosuresTables</ParentRole>
      <Position>123</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R124.htm</HtmlFileName>
      <LongName>2429405 - Disclosure - Supplemental Oil and Natural Gas Disclosures (Costs Incurred in Oil and Natural Gas Acquisition, Exploration and Development Activities) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SupplementalOilAndNaturalGasDisclosuresCostsIncurredInOilAndNaturalGasAcquisitionExplorationAndDevelopmentActivitiesDetails</Role>
      <ShortName>Supplemental Oil and Natural Gas Disclosures (Costs Incurred in Oil and Natural Gas Acquisition, Exploration and Development Activities) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SupplementalOilAndNaturalGasDisclosuresTables</ParentRole>
      <Position>124</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R125.htm</HtmlFileName>
      <LongName>2429406 - Disclosure - Supplemental Oil and Natural Gas Disclosures (Components Of The Standardized Measure Of Discounted Future Net Cash Flows) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SupplementalOilAndNaturalGasDisclosuresComponentsOfStandardizedMeasureOfDiscountedFutureNetCashFlowsDetails</Role>
      <ShortName>Supplemental Oil and Natural Gas Disclosures (Components Of The Standardized Measure Of Discounted Future Net Cash Flows) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SupplementalOilAndNaturalGasDisclosuresTables</ParentRole>
      <Position>125</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R126.htm</HtmlFileName>
      <LongName>2429407 - Disclosure - Supplemental Oil and Natural Gas Disclosures (Components Of Changes In Standardized Measure Of Discounted Future Net Cash Flows) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.altamesa.net/role/SupplementalOilAndNaturalGasDisclosuresComponentsOfChangesInStandardizedMeasureOfDiscountedFutureNetCashFlowsDetails</Role>
      <ShortName>Supplemental Oil and Natural Gas Disclosures (Components Of Changes In Standardized Measure Of Discounted Future Net Cash Flows) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.altamesa.net/role/SupplementalOilAndNaturalGasDisclosuresTables</ParentRole>
      <Position>126</Position>
    </Report>
    <Report instance="amr-20181231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9999.htm</HtmlFileName>
      <LongName>Uncategorized Items - amr-20181231.xml</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/role/uncategorizedFacts</Role>
      <ShortName>Uncategorized Items - amr-20181231.xml</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>127</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>amr-20181231.xml</File>
    <File>amr-20181231.xsd</File>
    <File>amr-20181231_cal.xml</File>
    <File>amr-20181231_def.xml</File>
    <File>amr-20181231_lab.xml</File>
    <File>amr-20181231_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy>http://xbrl.sec.gov/stpr/2018-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2019-01-31</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>
