<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.26.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>7934</ContextCount>
  <ElementCount>40</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>152</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>3</UnitCount>
  <MyReports>
    <Report instance="primary-document.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>030000 - Disclosure - Form N-CSR Cover</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/oef/role/NcsrCover</Role>
      <ShortName>Form N-CSR Cover</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="primary-document.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>030001 - Disclosure - Shareholder Report</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/oef/role/ShareholderReport</Role>
      <ShortName>Shareholder Report</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="primary-document.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>040010 - Disclosure - Shareholder Report, Line Graph (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/oef/role/ShareholderReportLineGraphDetails</Role>
      <ShortName>Shareholder Report, Line Graph (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="primary-document.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>040015 - Disclosure - Shareholder Report, Average Annual Return (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/oef/role/ShareholderReportAverageAnnualReturnDetails</Role>
      <ShortName>Shareholder Report, Average Annual Return (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="primary-document.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>040020 - Disclosure - Shareholder Report, Holdings (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/oef/role/ShareholderReportHoldingsDetails</Role>
      <ShortName>Shareholder Report, Holdings (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>mf-20260630.xsd</File>
    <File doctype="N-CSRS" isDefinitelyNotFs="true" isNcsr="true" isOEF="true" isRRorOEF="true" isUsgaap="true" original="primary-document.htm">primary-document.htm</File>
  </InputFiles>
  <SupplementalFiles>
    <File>i12b824efe978dd2fcf7e8b43.jpg</File>
    <File>i134a7c4b091a8b6f09c4a095.jpg</File>
    <File>i18bdf0003082e8d3830e41fb.jpg</File>
    <File>i1a7f663366ec7b4180be41ec.jpg</File>
    <File>i22210e318d8deae9dcd19fbe.jpg</File>
    <File>i2f759e43267f33abb4d0cb63.jpg</File>
    <File>i30e5841b6f6bf4cf96cb021a.jpg</File>
    <File>i33cbd138942d6a240e6d360a.jpg</File>
    <File>i34174f8fe3df1f8d8e1a96f2.jpg</File>
    <File>i38b6e71fe52b9226b9791942.jpg</File>
    <File>i42df8a61d1fd9c7e29043b87.jpg</File>
    <File>i471ff0434854c3bfe9a0825c.jpg</File>
    <File>i47c498f13211f642d0f0fdcb.jpg</File>
    <File>i4ab2e61b32d0d72f4aaf951c.jpg</File>
    <File>i51cee6378f100fc631437baa.jpg</File>
    <File>i534ad3a1aee047177a15892f.jpg</File>
    <File>i59b1cc3744584e27abfc0862.jpg</File>
    <File>i5abaac7dc39b88032392688d.jpg</File>
    <File>i5c681ecf706b56028855ce51.jpg</File>
    <File>i5dfbafda726181ac872ebb64.jpg</File>
    <File>i6184d9adb614eefeb0dba497.jpg</File>
    <File>i6540dd7af52e0536b6a87a5c.jpg</File>
    <File>i67484aecb11683f5d029fd3b.jpg</File>
    <File>i6b17c16928fcaddf00a712a9.jpg</File>
    <File>i6e01cb73c13f93040a5a78c1.jpg</File>
    <File>i6f830a336d058e3232f37ef3.jpg</File>
    <File>i7254bd3a2e6ff0102523a796.jpg</File>
    <File>i73ef2303b9ba3c37f65eb43a.jpg</File>
    <File>i753974d2f43cfc6354e59d1d.jpg</File>
    <File>i7deb5df7201c5ee64b41c384.jpg</File>
    <File>i8782f134c01227659c8da871.jpg</File>
    <File>i8d5ea69d96aaf2890f3350fe.jpg</File>
    <File>i93cba772b6a1952e61edc19f.jpg</File>
    <File>ia677cffb85d7c2644804aeae.jpg</File>
    <File>ia68387ba0856ca258aaa44b9.jpg</File>
    <File>ib5182da86108c96adfa474b1.jpg</File>
    <File>ib7116f5b5311592ce2485846.jpg</File>
    <File>ib874318ad67530cc1fee45af.jpg</File>
    <File>ic32d7862ee19dc2aadb6e9a9.jpg</File>
    <File>ic5d545327b742418f97a49c5.jpg</File>
    <File>ic6241f584d9d63b6ad97e668.jpg</File>
    <File>id138fca95f841f086ab534ed.jpg</File>
    <File>ie9254c7b4b6db9d32c8eb358.jpg</File>
    <File>iee390b174053f12822268e2a.jpg</File>
    <File>ief52fd4a510a2d1a4b3f58b4.jpg</File>
    <File>if162f6dff9637bb25e9a601e.jpg</File>
    <File>if52bbb7e1df1c25830c0fd28.jpg</File>
    <File>if9af3d58396941db63ef42fc.jpg</File>
    <File>ifecd11eeaae7b5c4787db85f.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="58">http://fasb.org/us-gaap/2025</BaseTaxonomy>
    <BaseTaxonomy items="128">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
    <BaseTaxonomy items="8834">http://xbrl.sec.gov/oef/2025</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>false</HasPresentationLinkbase>
  <HasCalculationLinkbase>false</HasCalculationLinkbase>
</FilingSummary>
