<?xml version='1.0' encoding='UTF-8'?>
<FilingSummary>
  <Version>3.8.0.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>366</ContextCount>
  <ElementCount>266</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>115</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>15</UnitCount>
  <MyReports>
    <Report instance="ugi-20171231.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.ugicorp.com/role/DocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001000 - Statement - Condensed Consolidated Balance Sheets (unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/CondensedConsolidatedBalanceSheetsUnaudited</Role>
      <ShortName>Condensed Consolidated Balance Sheets (unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1001501 - Statement - Condensed Consolidated Balance Sheets (unaudited) (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/CondensedConsolidatedBalanceSheetsUnauditedParenthetical</Role>
      <ShortName>Condensed Consolidated Balance Sheets (unaudited) (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1002000 - Statement - Condensed Consolidated Statements of Income (unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/CondensedConsolidatedStatementsOfIncomeUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Income (unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1003000 - Statement - Condensed Consolidated Statements of Comprehensive Income (unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/CondensedConsolidatedStatementsOfComprehensiveIncomeUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Comprehensive Income (unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1003501 - Statement - Condensed Consolidated Statements of Comprehensive Income (unaudited) (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/CondensedConsolidatedStatementsOfComprehensiveIncomeUnauditedParenthetical</Role>
      <ShortName>Condensed Consolidated Statements of Comprehensive Income (unaudited) (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>1004000 - Statement - Condensed Consolidated Statements of Cash Flows (unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/CondensedConsolidatedStatementsOfCashFlowsUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Cash Flows (unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>1005000 - Statement - Condensed Consolidated Statements of Changes in Equity (unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/CondensedConsolidatedStatementsOfChangesInEquityUnaudited</Role>
      <ShortName>Condensed Consolidated Statements of Changes in Equity (unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2101100 - Disclosure - Nature of Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/NatureOfOperations</Role>
      <ShortName>Nature of Operations</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2102100 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/SummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2103100 - Disclosure - Accounting Changes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/AccountingChanges</Role>
      <ShortName>Accounting Changes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2104100 - Disclosure - Inventories</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/Inventories</Role>
      <ShortName>Inventories</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2106100 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2107100 - Disclosure - Goodwill and Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/GoodwillAndIntangibleAssets</Role>
      <ShortName>Goodwill and Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2108100 - Disclosure - Utility Regulatory Assets and Liabilities and Regulatory Matters</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/UtilityRegulatoryAssetsAndLiabilitiesAndRegulatoryMatters</Role>
      <ShortName>Utility Regulatory Assets and Liabilities and Regulatory Matters</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2109100 - Disclosure - Energy Services Accounts Receivable Securitization Facility</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/EnergyServicesAccountsReceivableSecuritizationFacility</Role>
      <ShortName>Energy Services Accounts Receivable Securitization Facility</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2110100 - Disclosure - Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/Debt</Role>
      <ShortName>Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2113100 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/CommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2114100 - Disclosure - Defined Benefit Pension and Other Postretirement Plans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/DefinedBenefitPensionAndOtherPostretirementPlans</Role>
      <ShortName>Defined Benefit Pension and Other Postretirement Plans</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2116100 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/FairValueMeasurements</Role>
      <ShortName>Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2117100 - Disclosure - Derivative Instruments and Hedging Activities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/DerivativeInstrumentsAndHedgingActivities</Role>
      <ShortName>Derivative Instruments and Hedging Activities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2118100 - Disclosure - Accumulated Other Comprehensive Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/AccumulatedOtherComprehensiveIncome</Role>
      <ShortName>Accumulated Other Comprehensive Income</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2119100 - Disclosure - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/SegmentInformation</Role>
      <ShortName>Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2202201 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/SummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.ugicorp.com/role/SummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2302302 - Disclosure - Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/SummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.ugicorp.com/role/SummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2304301 - Disclosure - Inventories (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/InventoriesTables</Role>
      <ShortName>Inventories (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.ugicorp.com/role/Inventories</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2307301 - Disclosure - Goodwill and Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/GoodwillAndIntangibleAssetsTables</Role>
      <ShortName>Goodwill and Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.ugicorp.com/role/GoodwillAndIntangibleAssets</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2308301 - Disclosure - Utility Regulatory Assets and Liabilities and Regulatory Matters (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/UtilityRegulatoryAssetsAndLiabilitiesAndRegulatoryMattersTables</Role>
      <ShortName>Utility Regulatory Assets and Liabilities and Regulatory Matters (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.ugicorp.com/role/UtilityRegulatoryAssetsAndLiabilitiesAndRegulatoryMatters</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2309301 - Disclosure - Energy Services Accounts Receivable Securitization Facility (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/EnergyServicesAccountsReceivableSecuritizationFacilityTables</Role>
      <ShortName>Energy Services Accounts Receivable Securitization Facility (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.ugicorp.com/role/EnergyServicesAccountsReceivableSecuritizationFacility</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2314301 - Disclosure - Defined Benefit Pension and Other Postretirement Plans (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/DefinedBenefitPensionAndOtherPostretirementPlansTables</Role>
      <ShortName>Defined Benefit Pension and Other Postretirement Plans (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.ugicorp.com/role/DefinedBenefitPensionAndOtherPostretirementPlans</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2316301 - Disclosure - Fair Value Measurement (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/FairValueMeasurementTables</Role>
      <ShortName>Fair Value Measurement (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.ugicorp.com/role/FairValueMeasurements</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2317301 - Disclosure - Derivative Instruments and Hedging Activities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/DerivativeInstrumentsAndHedgingActivitiesTables</Role>
      <ShortName>Derivative Instruments and Hedging Activities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.ugicorp.com/role/DerivativeInstrumentsAndHedgingActivities</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2318301 - Disclosure - Accumulated Other Comprehensive Income (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/AccumulatedOtherComprehensiveIncomeTables</Role>
      <ShortName>Accumulated Other Comprehensive Income (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.ugicorp.com/role/AccumulatedOtherComprehensiveIncome</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2319301 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/SegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.ugicorp.com/role/SegmentInformation</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2401401 - Disclosure - Nature of Operations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/NatureOfOperationsDetails</Role>
      <ShortName>Nature of Operations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.ugicorp.com/role/NatureOfOperations</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2402403 - Disclosure - Summary of Significant Accounting Policies - Shares Used in Computing Basic and Diluted Earnings Per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/SummaryOfSignificantAccountingPoliciesSharesUsedInComputingBasicAndDilutedEarningsPerShareDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Shares Used in Computing Basic and Diluted Earnings Per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2404402 - Disclosure - Inventories - Components of Inventories (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/InventoriesComponentsOfInventoriesDetails</Role>
      <ShortName>Inventories - Components of Inventories (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2404403 - Disclosure - Inventories - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/InventoriesNarrativeDetails</Role>
      <ShortName>Inventories - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2406401 - Disclosure - Income Taxes - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/IncomeTaxesNarrativeDetails</Role>
      <ShortName>Income Taxes - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2407402 - Disclosure - Goodwill and Intangible Assets - Components of Company's Goodwill and Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/GoodwillAndIntangibleAssetsComponentsOfCompanysGoodwillAndIntangibleAssetsDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Components of Company's Goodwill and Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2407403 - Disclosure - Goodwill and Intangible Assets - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/GoodwillAndIntangibleAssetsNarrativeDetails</Role>
      <ShortName>Goodwill and Intangible Assets - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2408402 - Disclosure - Utility Regulatory Assets and Liabilities and Regulatory Matters - Regulatory Assets and Liabilities Associated with Gas Utility and Electric Utility (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/UtilityRegulatoryAssetsAndLiabilitiesAndRegulatoryMattersRegulatoryAssetsAndLiabilitiesAssociatedWithGasUtilityAndElectricUtilityDetails</Role>
      <ShortName>Utility Regulatory Assets and Liabilities and Regulatory Matters - Regulatory Assets and Liabilities Associated with Gas Utility and Electric Utility (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2408403 - Disclosure - Utility Regulatory Assets and Liabilities and Regulatory Matters - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/UtilityRegulatoryAssetsAndLiabilitiesAndRegulatoryMattersNarrativeDetails</Role>
      <ShortName>Utility Regulatory Assets and Liabilities and Regulatory Matters - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.ugicorp.com/role/UtilityRegulatoryAssetsAndLiabilitiesAndRegulatoryMattersTables</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>2409402 - Disclosure - Energy Services Accounts Receivable Securitization Facility - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/EnergyServicesAccountsReceivableSecuritizationFacilityNarrativeDetails</Role>
      <ShortName>Energy Services Accounts Receivable Securitization Facility - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.ugicorp.com/role/EnergyServicesAccountsReceivableSecuritizationFacilityTables</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>2409403 - Disclosure - Energy Services Accounts Receivable Securitization Facility - Trade Receivables Transferred and Sold (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/EnergyServicesAccountsReceivableSecuritizationFacilityTradeReceivablesTransferredAndSoldDetails</Role>
      <ShortName>Energy Services Accounts Receivable Securitization Facility - Trade Receivables Transferred and Sold (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>2410401 - Disclosure - Debt - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/DebtNarrativeDetails</Role>
      <ShortName>Debt - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>2413401 - Disclosure - Commitments and Contingencies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/CommitmentsAndContingenciesDetails</Role>
      <ShortName>Commitments and Contingencies (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.ugicorp.com/role/CommitmentsAndContingencies</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>2414402 - Disclosure - Defined Benefit Pension and Other Postretirement Plans - Components of Net Periodic Pension Expense and Other Postretirement Benefit Costs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/DefinedBenefitPensionAndOtherPostretirementPlansComponentsOfNetPeriodicPensionExpenseAndOtherPostretirementBenefitCostsDetails</Role>
      <ShortName>Defined Benefit Pension and Other Postretirement Plans - Components of Net Periodic Pension Expense and Other Postretirement Benefit Costs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>2414403 - Disclosure - Defined Benefit Pension and Other Postretirement Plans - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/DefinedBenefitPensionAndOtherPostretirementPlansNarrativeDetails</Role>
      <ShortName>Defined Benefit Pension and Other Postretirement Plans - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.ugicorp.com/role/DefinedBenefitPensionAndOtherPostretirementPlansTables</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>2416402 - Disclosure - Fair Value Measurements - Financial Assets and Liabilities that are Measured at Fair Value on a Recurring Basis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/FairValueMeasurementsFinancialAssetsAndLiabilitiesThatAreMeasuredAtFairValueOnRecurringBasisDetails</Role>
      <ShortName>Fair Value Measurements - Financial Assets and Liabilities that are Measured at Fair Value on a Recurring Basis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>2416403 - Disclosure - Fair Value Measurements - Long-term Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/FairValueMeasurementsLongTermDebtDetails</Role>
      <ShortName>Fair Value Measurements - Long-term Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>2417402 - Disclosure - Derivative Instruments and Hedging Activities - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/DerivativeInstrumentsAndHedgingActivitiesNarrativeDetails</Role>
      <ShortName>Derivative Instruments and Hedging Activities - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>2417403 - Disclosure - Derivative Instruments and Hedging Activities - Schedule of Notional Amounts (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/DerivativeInstrumentsAndHedgingActivitiesScheduleOfNotionalAmountsDetails</Role>
      <ShortName>Derivative Instruments and Hedging Activities - Schedule of Notional Amounts (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>2417404 - Disclosure - Derivative Instruments and Hedging Activities - Fair Value of Derivative Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/DerivativeInstrumentsAndHedgingActivitiesFairValueOfDerivativeAssetsAndLiabilitiesDetails</Role>
      <ShortName>Derivative Instruments and Hedging Activities - Fair Value of Derivative Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>2417405 - Disclosure - Derivative Instruments and Hedging Activities - Effects of Derivative Instruments on the Condensed Consolidated Statements of Income and Changes in AOCI (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/DerivativeInstrumentsAndHedgingActivitiesEffectsOfDerivativeInstrumentsOnCondensedConsolidatedStatementsOfIncomeAndChangesInAociDetails</Role>
      <ShortName>Derivative Instruments and Hedging Activities - Effects of Derivative Instruments on the Condensed Consolidated Statements of Income and Changes in AOCI (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>2418402 - Disclosure - Accumulated Other Comprehensive Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/AccumulatedOtherComprehensiveIncomeDetails</Role>
      <ShortName>Accumulated Other Comprehensive Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.ugicorp.com/role/AccumulatedOtherComprehensiveIncomeTables</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>2419402 - Disclosure - Segment Information - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/SegmentInformationNarrativeDetails</Role>
      <ShortName>Segment Information - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>2419403 - Disclosure - Segment Information - Schedule of Segment Reporting Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/SegmentInformationScheduleOfSegmentReportingInformationDetails</Role>
      <ShortName>Segment Information - Schedule of Segment Reporting Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="ugi-20171231.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>2419404 - Disclosure - Segment Information - Reconciliation of Partnership Adjusted EBITDA (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.ugicorp.com/role/SegmentInformationReconciliationOfPartnershipAdjustedEbitdaDetails</Role>
      <ShortName>Segment Information - Reconciliation of Partnership Adjusted EBITDA (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>ugi-20171231.xml</File>
    <File>ugi-20171231.xsd</File>
    <File>ugi-20171231_cal.xml</File>
    <File>ugi-20171231_def.xml</File>
    <File>ugi-20171231_lab.xml</File>
    <File>ugi-20171231_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy>http://xbrl.sec.gov/invest/2013-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2014-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/us-gaap/2017-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
