<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.24.3</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>106</ContextCount>
  <ElementCount>83</ElementCount>
  <EntityCount>2</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>71</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>6</UnitCount>
  <MyReports>
    <Report instance="ck0001535778-20241003.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>995100 - Document - Cover</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/dei/role/document/Cover</Role>
      <ShortName>Cover</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="ck0001535778-20241003.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>995470 - Disclosure - N-2</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/cef/role/N2</Role>
      <ShortName>N-2</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="exfilingfees.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>995210 - Document - Submission</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ffd/role/document/submissionTable</Role>
      <ShortName>Submission</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="exfilingfees.htm">
      <IsDefault>true</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>995211 - Document - Offerings</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ffd/role/document/feesOfferingTable</Role>
      <ShortName>Offerings</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="exfilingfees.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>995215 - Document - Fees Summary</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ffd/role/document/feesSummaryTable</Role>
      <ShortName>Fees Summary</ShortName>
      <MenuCategory>Cover</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 doctype="N-2" isN2Prospectus="true" isUsgaap="true" original="ck0001535778-20241003.htm">ck0001535778-20241003.htm</File>
    <File>ck0001535778-20241003.xsd</File>
    <File>ck0001535778-20241003_def.xml</File>
    <File>ck0001535778-20241003_lab.xml</File>
    <File>ck0001535778-20241003_pre.xml</File>
    <File doctype="EX-FILING FEES" original="exfilingfees.htm">exfilingfees.htm</File>
  </InputFiles>
  <SupplementalFiles>
    <File>ck0001535778-20241003_g1.jpg</File>
    <File>ck0001535778-20241003_g2.jpg</File>
    <File>ck0001535778-20241003_g3.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="166">http://xbrl.sec.gov/cef/2023</BaseTaxonomy>
    <BaseTaxonomy items="31">http://xbrl.sec.gov/dei/2023</BaseTaxonomy>
    <BaseTaxonomy items="3">http://xbrl.sec.gov/dei/2024</BaseTaxonomy>
    <BaseTaxonomy items="17">http://xbrl.sec.gov/ffd/2024q2</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>false</HasCalculationLinkbase>
</FilingSummary>
