<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.25.0.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>99</ContextCount>
  <ElementCount>78</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>38</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>2</UnitCount>
  <MyReports>
    <Report instance="d894476d485bpos.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>000000 - Document - Document and Entity Information {Elements}</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.jpmorganfunds.com/role/DocumentDocumentandEntityInformationElements</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Risk/Return</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="d894476d485bpos.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>000019 - Disclosure - Risk/Return Detail Data {Elements} - JPMorgan Emerging Markets Research Enhanced Equity Fund (I Shares)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.jpmorganfunds.com/role/DisclosureRiskReturnDetailDataElementsJPMorganEmergingMarketsResearchEnhancedEquityFundIShares</Role>
      <ShortName>Risk/Return Detail Data- JPMorgan Emerging Markets Research Enhanced Equity Fund (I Shares)</ShortName>
      <MenuCategory>Risk/Return</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="d894476d485bpos.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>000029 - Disclosure - Risk/Return Detail Data {Elements} - JPMorgan International Hedged Equity Fund (A C I Shares)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.jpmorganfunds.com/role/DisclosureRiskReturnDetailDataElementsJPMorganInternationalHedgedEquityFundACIShares</Role>
      <ShortName>Risk/Return Detail Data- JPMorgan International Hedged Equity Fund (A C I Shares)</ShortName>
      <MenuCategory>Risk/Return</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="d894476d485bpos.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>000039 - Disclosure - Risk/Return Detail Data {Elements} - JPMorgan Emerging Markets Research Enhanced Equity Fund (R6 Shares)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.jpmorganfunds.com/role/DisclosureRiskReturnDetailDataElementsJPMorganEmergingMarketsResearchEnhancedEquityFundR6Shares</Role>
      <ShortName>Risk/Return Detail Data- JPMorgan Emerging Markets Research Enhanced Equity Fund (R6 Shares)</ShortName>
      <MenuCategory>Risk/Return</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="d894476d485bpos.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>000049 - Disclosure - Risk/Return Detail Data {Elements} - JPMorgan International Hedged Equity Fund (R6 Shares)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.jpmorganfunds.com/role/DisclosureRiskReturnDetailDataElementsJPMorganInternationalHedgedEquityFundR6Shares</Role>
      <ShortName>Risk/Return Detail Data- JPMorgan International Hedged Equity Fund (R6 Shares)</ShortName>
      <MenuCategory>Risk/Return</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="d894476d485bpos.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>040000 - Disclosure - Risk/Return Detail Data {Elements}</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/rr/role/RiskReturnDetailData</Role>
      <ShortName>Risk/Return Detail Data</ShortName>
      <MenuCategory>Risk/Return</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File doctype="485BPOS" isN1a="true" isRR="true" isRRorOEF="true" original="d894476d485bpos.htm">d894476d485bpos.htm</File>
    <File>jpmt4-20250224.xsd</File>
    <File>jpmt4-20250224_cal.xml</File>
    <File>jpmt4-20250224_def.xml</File>
    <File>jpmt4-20250224_lab.xml</File>
    <File>jpmt4-20250224_pre.xml</File>
  </InputFiles>
  <SupplementalFiles>
    <File>g894476fsc_proslogo.gif</File>
    <File>g894476img098bf88c2.jpg</File>
    <File>g894476img2801b1743.jpg</File>
    <File>g894476img2ce558115.jpg</File>
    <File>g894476img360b29c64.jpg</File>
    <File>g894476img504574b39.jpg</File>
    <File>g894476img59e946707.jpg</File>
    <File>g894476img663031613.jpg</File>
    <File>g894476img7aaa0c4a7.jpg</File>
    <File>g894476img9ad0dccc6.jpg</File>
    <File>g894476img9e67061f6.jpg</File>
    <File>g894476imga1eeed0b2.jpg</File>
    <File>g894476imga9c1d2751.jpg</File>
    <File>g894476imgaff251688.jpg</File>
    <File>g894476imgbd0d25365.jpg</File>
    <File>g894476imgbd7071764.jpg</File>
    <File>g894476imgf3d5bce310.jpg</File>
    <File>g894476imgf6dad9ef1.jpg</File>
    <File>g894476logo_back.gif</File>
    <File>g894476logo_front.gif</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="14">http://xbrl.sec.gov/dei/2023</BaseTaxonomy>
    <BaseTaxonomy items="380">http://xbrl.sec.gov/rr/2023</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
