<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.22.2.2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>267</ContextCount>
  <ElementCount>282</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>69</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>4</UnitCount>
  <MyReports>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0000001 - Document - Cover</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/Cover</Role>
      <ShortName>Cover</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>0000003 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/ConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>0000004 - Statement - Consolidated Balance Sheet (Parentheticals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/ConsolidatedBalanceSheetParentheticals</Role>
      <ShortName>Consolidated Balance Sheet (Parentheticals)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>0000005 - Statement - Consolidated Statements of Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/ConsolidatedStatementsofOperations</Role>
      <ShortName>Consolidated Statements of Operations</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>0000006 - Statement - Consolidated Statements of Operations (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/ConsolidatedStatementsofOperationsParenthetical</Role>
      <ShortName>Consolidated Statements of Operations (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>0000007 - Statement - Consolidated Statements of Changes in Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/ConsolidatedStatementsofChangesinEquity</Role>
      <ShortName>Consolidated Statements of Changes in Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>0000009 - Statement - Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/ConsolidatedStatementsofCashFlows</Role>
      <ShortName>Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>0000010 - Statement - Consolidated Statements of Cash Flows Consolidated Statement of Cash Flows - Supplemental cash information - (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/ConsolidatedStatementsofCashFlowsConsolidatedStatementofCashFlowsSupplementalcashinformationParenthetical</Role>
      <ShortName>Consolidated Statements of Cash Flows Consolidated Statement of Cash Flows - Supplemental cash information - (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>0000011 - Statement - Consolidated Schedule of Investment</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/ConsolidatedScheduleofInvestment</Role>
      <ShortName>Consolidated Schedule of Investment</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>0000012 - Statement - Consolidated Schedule of Investment (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/ConsolidatedScheduleofInvestmentParenthetical</Role>
      <ShortName>Consolidated Schedule of Investment (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>0000013 - Disclosure - Principal Business and Organization</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/PrincipalBusinessandOrganization</Role>
      <ShortName>Principal Business and Organization</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>0000014 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/SummaryofSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>0000015 - Disclosure - Investments and Fair Value</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/InvestmentsandFairValue</Role>
      <ShortName>Investments and Fair Value</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>0000016 - Disclosure - Related Party Transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/RelatedPartyTransactions</Role>
      <ShortName>Related Party Transactions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>0000017 - Disclosure - Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/Debt</Role>
      <ShortName>Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>0000018 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/CommitmentsandContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>0000019 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>0000020 - Disclosure - Directors Fees</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/DirectorsFees</Role>
      <ShortName>Directors Fees</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>0000021 - Disclosure - Capital</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/Capital</Role>
      <ShortName>Capital</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>0000022 - Disclosure - Net Increase in Net Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/NetIncreaseinNetAssets</Role>
      <ShortName>Net Increase in Net Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>0000023 - Disclosure - Distribution</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/Distribution</Role>
      <ShortName>Distribution</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>0000024 - Disclosure - Financial Highlights</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/FinancialHighlights</Role>
      <ShortName>Financial Highlights</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>0000025 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/SubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>0000026 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/SummaryofSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://terrafund6.com/role/SummaryofSignificantAccountingPolicies</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>0000027 - Disclosure - Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/SummaryofSignificantAccountingPoliciesTables</Role>
      <ShortName>Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://terrafund6.com/role/SummaryofSignificantAccountingPolicies</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>0000028 - Disclosure - Investments and Fair Value (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/InvestmentsandFairValueTables</Role>
      <ShortName>Investments and Fair Value (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://terrafund6.com/role/InvestmentsandFairValue</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>0000029 - Disclosure - Related Party Transactions (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/RelatedPartyTransactionsTables</Role>
      <ShortName>Related Party Transactions (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://terrafund6.com/role/RelatedPartyTransactions</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>0000030 - Disclosure - Debt (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/DebtTables</Role>
      <ShortName>Debt (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://terrafund6.com/role/Debt</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>0000032 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/IncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://terrafund6.com/role/IncomeTaxes</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>0000034 - Disclosure - Capital (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/CapitalTables</Role>
      <ShortName>Capital (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://terrafund6.com/role/Capital</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>0000035 - Disclosure - Net Increase in Net Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/NetIncreaseinNetAssetsTables</Role>
      <ShortName>Net Increase in Net Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://terrafund6.com/role/NetIncreaseinNetAssets</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>0000036 - Disclosure - Distribution (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/DistributionTables</Role>
      <ShortName>Distribution (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://terrafund6.com/role/Distribution</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>0000037 - Disclosure - Financial Highlights (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/FinancialHighlightsTables</Role>
      <ShortName>Financial Highlights (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://terrafund6.com/role/FinancialHighlights</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>0000039 - Disclosure - Principal Business and Organization (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/PrincipalBusinessandOrganizationDetails</Role>
      <ShortName>Principal Business and Organization (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://terrafund6.com/role/PrincipalBusinessandOrganization</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>0000040 - Disclosure - Summary of Significant Accounting Policies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/SummaryofSignificantAccountingPoliciesDetails</Role>
      <ShortName>Summary of Significant Accounting Policies (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://terrafund6.com/role/SummaryofSignificantAccountingPoliciesTables</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>0000041 - Disclosure - Summary of Significant Accounting Policies -Narratives (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/SummaryofSignificantAccountingPoliciesNarrativesDetails</Role>
      <ShortName>Summary of Significant Accounting Policies -Narratives (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>0000042 - Disclosure - Investments and Fair Value (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/InvestmentsandFairValueDetails</Role>
      <ShortName>Investments and Fair Value (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://terrafund6.com/role/InvestmentsandFairValueTables</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>0000043 - Disclosure - Investments and Fair Value - Obligations under Participation Agreements -Narratives (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/InvestmentsandFairValueObligationsunderParticipationAgreementsNarrativesDetails</Role>
      <ShortName>Investments and Fair Value - Obligations under Participation Agreements -Narratives (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>0000044 - Disclosure - Investments and Fair Value - Fair value measurements of investments by major class (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/InvestmentsandFairValueFairvaluemeasurementsofinvestmentsbymajorclassDetails</Role>
      <ShortName>Investments and Fair Value - Fair value measurements of investments by major class (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>0000045 - Disclosure - Investments and Fair Value - Changes in the Company???s Level 3 investments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/InvestmentsandFairValueChangesintheCompanysLevel3investmentsDetails</Role>
      <ShortName>Investments and Fair Value - Changes in the Company???s Level 3 investments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>0000046 - Disclosure - Investments and Fair Value - Valuation techniques and unobservable inputs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/InvestmentsandFairValueValuationtechniquesandunobservableinputsDetails</Role>
      <ShortName>Investments and Fair Value - Valuation techniques and unobservable inputs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>0000047 - Disclosure - Investments and Fair Value- Not carried at Fair Value (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/InvestmentsandFairValueNotcarriedatFairValueDetails</Role>
      <ShortName>Investments and Fair Value- Not carried at Fair Value (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>0000048 - Disclosure - Investments and Fair Value- Not carried at Fair Value - Subnote (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/InvestmentsandFairValueNotcarriedatFairValueSubnoteDetails</Role>
      <ShortName>Investments and Fair Value- Not carried at Fair Value - Subnote (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>0000049 - Disclosure - Related Party Transactions - Summary of fees and reimbursement (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/RelatedPartyTransactionsSummaryoffeesandreimbursementDetails</Role>
      <ShortName>Related Party Transactions - Summary of fees and reimbursement (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>0000050 - Disclosure - Related Party Transactions - Summary of fees and reimbursement-subnote (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/RelatedPartyTransactionsSummaryoffeesandreimbursementsubnoteDetails</Role>
      <ShortName>Related Party Transactions - Summary of fees and reimbursement-subnote (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>0000051 - Disclosure - Related Party Transactions - Due to Related Party - Narratives (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/RelatedPartyTransactionsDuetoRelatedPartyNarrativesDetails</Role>
      <ShortName>Related Party Transactions - Due to Related Party - Narratives (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>0000052 - Disclosure - Related Party Transactions - Due to / Due from Adviser (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/RelatedPartyTransactionsDuetoDuefromAdviserDetails</Role>
      <ShortName>Related Party Transactions - Due to / Due from Adviser (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>0000053 - Disclosure - Related Party Transactions - Due to / Due from Adviser - Subnote (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/RelatedPartyTransactionsDuetoDuefromAdviserSubnoteDetails</Role>
      <ShortName>Related Party Transactions - Due to / Due from Adviser - Subnote (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>0000054 - Disclosure - Related Party Transactions - Management and Incentive Fee Compensation to Adviser (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/RelatedPartyTransactionsManagementandIncentiveFeeCompensationtoAdviserDetails</Role>
      <ShortName>Related Party Transactions - Management and Incentive Fee Compensation to Adviser (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>0000055 - Disclosure - Related Party Transactions - Transfers of Participation Interest (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/RelatedPartyTransactionsTransfersofParticipationInterestDetails</Role>
      <ShortName>Related Party Transactions - Transfers of Participation Interest (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>0000056 - Disclosure - Debt - Narratives - Unsecured Notes Payable (Details)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://terrafund6.com/role/DebtNarrativesUnsecuredNotesPayableDetails</Role>
      <ShortName>Debt - Narratives - Unsecured Notes Payable (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>0000057 - Disclosure - Debt - Narratives - Term Loan (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/DebtNarrativesTermLoanDetails</Role>
      <ShortName>Debt - Narratives - Term Loan (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>0000058 - Disclosure - Debt - Component of interest expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/DebtComponentofinterestexpenseDetails</Role>
      <ShortName>Debt - Component of interest expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>0000059 - Disclosure - Commitments and Contingencies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/CommitmentsandContingenciesDetails</Role>
      <ShortName>Commitments and Contingencies (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://terrafund6.com/role/CommitmentsandContingencies</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>0000060 - Disclosure - Income Taxes - Reconciliation of net increase in net assets resulting from operations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/IncomeTaxesReconciliationofnetincreaseinnetassetsresultingfromoperationsDetails</Role>
      <ShortName>Income Taxes - Reconciliation of net increase in net assets resulting from operations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>0000061 - Disclosure - Income Taxes - Narratives - Taxable REIT Subsidiary (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/IncomeTaxesNarrativesTaxableREITSubsidiaryDetails</Role>
      <ShortName>Income Taxes - Narratives - Taxable REIT Subsidiary (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>0000062 - Disclosure - Income Taxes - Source Distribution (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/IncomeTaxesSourceDistributionDetails</Role>
      <ShortName>Income Taxes - Source Distribution (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>0000063 - Disclosure - Directors Fees (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/DirectorsFeesDetails</Role>
      <ShortName>Directors Fees (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://terrafund6.com/role/DirectorsFees</ParentRole>
      <Position>58</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>0000064 - Disclosure - Capital (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/CapitalDetails</Role>
      <ShortName>Capital (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://terrafund6.com/role/CapitalTables</ParentRole>
      <Position>59</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>0000065 - Disclosure - Capital - Repurchases of common stock (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/CapitalRepurchasesofcommonstockDetails</Role>
      <ShortName>Capital - Repurchases of common stock (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>0000066 - Disclosure - Capital - Repurchases of common stock - subnote (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/CapitalRepurchasesofcommonstocksubnoteDetails</Role>
      <ShortName>Capital - Repurchases of common stock - subnote (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>0000067 - Disclosure - Net Increase in Net Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/NetIncreaseinNetAssetsDetails</Role>
      <ShortName>Net Increase in Net Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://terrafund6.com/role/NetIncreaseinNetAssetsTables</ParentRole>
      <Position>62</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>0000068 - Disclosure - Distribution (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/DistributionDetails</Role>
      <ShortName>Distribution (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://terrafund6.com/role/DistributionTables</ParentRole>
      <Position>63</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>0000069 - Disclosure - Financial Highlights (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/FinancialHighlightsDetails</Role>
      <ShortName>Financial Highlights (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://terrafund6.com/role/FinancialHighlightsTables</ParentRole>
      <Position>64</Position>
    </Report>
    <Report instance="tfsa-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>0000070 - Disclosure - Subsequent Events (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://terrafund6.com/role/SubsequentEventsDetails</Role>
      <ShortName>Subsequent Events (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://terrafund6.com/role/SubsequentEvents</ParentRole>
      <Position>65</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <Logs>
    <Log type="Warning">[dq-0542-Deprecated-Concept] Concept WeightedAverageNumberOfShareOutstandingBasicAndDiluted in us-gaap/2021 used in 4 facts was deprecated in us-gaap/2022 as of 2022 and should not be used. tfsa-20220930.htm 4</Log>
    <Log type="Warning">[dq-0540-EntitySmallBusiness-Missing] Submission type 10-Q should have a non-empty value for EntitySmallBusiness in the Required Context. tfsa-20220930.htm </Log>
    <Log type="Warning">[dq-0540-EntityEmergingGrowthCompany-Missing] Submission type 10-Q should have a non-empty value for EntityEmergingGrowthCompany in the Required Context. tfsa-20220930.htm </Log>
    <Log type="Warning">[dq-0540-EntityExTransitionPeriod-EntityEmergingGrowthCompany-Dependency] In submission type 10-Q, EntityExTransitionPeriod must have a value if EntityEmergingGrowthCompany has value "true" in context i9e1212472226486f8d0ab76129d6a05c_D20220101-20220930, else it should not be provided. tfsa-20220930.htm 4</Log>
    <Log type="Warning">[dq-0526-EntityCommonStockSharesOutstanding-Missing] Submission type 10-Q should have a non-empty value for EntityCommonStockSharesOutstanding in the Required Context (one class of stock axis). tfsa-20220930.htm </Log>
    <Log type="Warning">[ix-0514-Hidden-Fact-Eligible-For-Transform] WARN: 45 fact(s) appearing in ix:hidden were eligible for transformation: dei:DocumentPeriodEndDate, tfsa:StockRepurchaseProgramAveragePricePaidPerShare, tfsa:StockRepurchaseProgramNumberOfSharesRepurchased, us-gaap:CommonStockParOrStatedValuePerShare, us-gaap:CommonStockSharesAuthorized, us-gaap:CommonStockSharesIssued, us-gaap:CommonStockSharesOutstanding, us-gaap:DebtInstrumentFaceAmount, us-gaap:DerivativeFloorInterestRate, us-gaap:IncentiveFeeExpense, us-gaap:InvestmentOwnedAtCost, us-gaap:LoansReceivableBasisSpreadOnVariableRate, us-gaap:LoansReceivableDescriptionOfVariableRateBasis, us-gaap:ManagementFeeExpense, us-gaap:OtherGeneralExpense, us-gaap:StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased, us-gaap:UnamortizedDebtIssuanceExpense -  tfsa-20220930.htm 4</Log>
    <Log type="Warning">[dqc-0008-Reversed-Calculation] The calculation in the extension taxonomy from us-gaap:NetInvestmentIncome to us-gaap:Revenues in 0000005 - Statement - Consolidated Statements of Operations is the opposite of a calculation defined in the base US GAAP taxonomy. Check that the calculation is correct or that you have used the correct tag for the two elements identified in the calculation. It is possible that the calculation is correct in the case of a reconciliation calculation. Rule Element Id: 6819. tfsa-20220930_cal.xml 56</Log>
    <Log type="Warning">[dqc-0015-Negative-Values] Fact us-gaap:IncentiveFeeExpense has a value of -102160 which is less than zero. This element should not have a negative value. The preparer should consider if the value is input correctly for this assertion and, after considering the appropriateness of the input, if incorrect, input the amount as a positive (i.e., absolute) value and provide a negated label. The properties of this us-gaap:IncentiveFeeExpense fact are: Context: i9e1212472226486f8d0ab76129d6a05c_D20220101-20220930, Unit: usd, Rule Element Id: 1301. tfsa-20220930.htm 4</Log>
    <Log type="Warning">[dqc-0015-Negative-Values] Fact us-gaap:AccumulatedDistributionsInExcessOfNetIncome has a value of -3008658 which is less than zero. This element should not have a negative value. The preparer should consider if the value is input correctly for this assertion and, after considering the appropriateness of the input, if incorrect, input the amount as a positive (i.e., absolute) value and provide a negated label. The properties of this us-gaap:AccumulatedDistributionsInExcessOfNetIncome fact are: Context: idbb97ad7582048d7b34637dff0c0a298_I20220930, Unit: usd, Rule Element Id: 2945. tfsa-20220930.htm 4</Log>
    <Log type="Warning">[dqc-0015-Negative-Values] Fact us-gaap:IncentiveFeeExpense has a value of -68486 which is less than zero. This element should not have a negative value. The preparer should consider if the value is input correctly for this assertion and, after considering the appropriateness of the input, if incorrect, input the amount as a positive (i.e., absolute) value and provide a negated label. The properties of this us-gaap:IncentiveFeeExpense fact are: Context: i55cbfce55583454e979d013783e3f718_D20220701-20220930, Unit: usd, Rule Element Id: 1301. tfsa-20220930.htm 4</Log>
    <Log type="Warning">[dqc-0015-Negative-Values] Fact us-gaap:IncentiveFeeExpense has a value of -90614 which is less than zero. This element should not have a negative value. The preparer should consider if the value is input correctly for this assertion and, after considering the appropriateness of the input, if incorrect, input the amount as a positive (i.e., absolute) value and provide a negated label. The properties of this us-gaap:IncentiveFeeExpense fact are: Context: i570954f5b02e4f34b3f86a199b4b3eb5_D20210701-20210930, Unit: usd, Rule Element Id: 1301. tfsa-20220930.htm 4</Log>
    <Log type="Warning">[dqc-0015-Negative-Values] Fact us-gaap:OtherExpenses has a value of -361611 which is less than zero. This element should not have a negative value. The preparer should consider if the value is input correctly for this assertion and, after considering the appropriateness of the input, if incorrect, input the amount as a positive (i.e., absolute) value and provide a negated label. The properties of this us-gaap:OtherExpenses fact are: Context: i55cbfce55583454e979d013783e3f718_D20220701-20220930, Unit: usd, Rule Element Id: 1873. tfsa-20220930.htm 4</Log>
    <Log type="Warning">[dqc-0015-Negative-Values] Fact us-gaap:OtherExpenses has a value of -121504 which is less than zero. This element should not have a negative value. The preparer should consider if the value is input correctly for this assertion and, after considering the appropriateness of the input, if incorrect, input the amount as a positive (i.e., absolute) value and provide a negated label. The properties of this us-gaap:OtherExpenses fact are: Context: i9e1212472226486f8d0ab76129d6a05c_D20220101-20220930, Unit: usd, Rule Element Id: 1873. tfsa-20220930.htm 4</Log>
    <Log type="Warning">[dqc-0015-Negative-Values] Fact us-gaap:PaidInKindInterest has a value of -94524 which is less than zero. This element should not have a negative value. The preparer should consider if the value is input correctly for this assertion and, after considering the appropriateness of the input, if incorrect, input the amount as a positive (i.e., absolute) value and provide a negated label. The properties of this us-gaap:PaidInKindInterest fact are: Context: i065422959fd447febacecae0746ba577_D20210101-20210930, Unit: usd, Rule Element Id: 2950. tfsa-20220930.htm 4</Log>
    <Log type="Warning">[dqc-0015-Negative-Values] Fact us-gaap:ProceedsFromSaleAndCollectionOfLoansReceivable has a value of -660753 which is less than zero. This element should not have a negative value. The preparer should consider if the value is input correctly for this assertion and, after considering the appropriateness of the input, if incorrect, input the amount as a positive (i.e., absolute) value and provide a negated label. The properties of this us-gaap:ProceedsFromSaleAndCollectionOfLoansReceivable fact are: Context: i065422959fd447febacecae0746ba577_D20210101-20210930, Unit: usd, Rule Element Id: 5029. tfsa-20220930.htm 4</Log>
    <Log type="Warning">[dqc-0015-Negative-Values] Fact us-gaap:InvestmentCompanyDistributionToShareholdersPerShare has a value of -0.24 which is less than zero. This element should not have a negative value. The preparer should consider if the value is input correctly for this assertion and, after considering the appropriateness of the input, if incorrect, input the amount as a positive (i.e., absolute) value and provide a negated label. The properties of this us-gaap:InvestmentCompanyDistributionToShareholdersPerShare fact are: Context: i9e1212472226486f8d0ab76129d6a05c_D20220101-20220930, Unit: usdPerShare, Rule Element Id: 6943. tfsa-20220930.htm 4</Log>
    <Log type="Warning">[dqc-0015-Negative-Values] Fact us-gaap:InvestmentCompanyDistributionToShareholdersPerShare has a value of -0.27 which is less than zero. This element should not have a negative value. The preparer should consider if the value is input correctly for this assertion and, after considering the appropriateness of the input, if incorrect, input the amount as a positive (i.e., absolute) value and provide a negated label. The properties of this us-gaap:InvestmentCompanyDistributionToShareholdersPerShare fact are: Context: i065422959fd447febacecae0746ba577_D20210101-20210930, Unit: usdPerShare, Rule Element Id: 6943. tfsa-20220930.htm 4</Log>
    <Log type="Warning">[dqc-0043-Incorrect-Calculation-Weights-In-Operating-Cash-Flows] The concept UnrealizedGainLossOnSecurities is included in the calculation of NetCashProvidedByUsedInOperatingActivities.UnrealizedGainLossOnSecurities is a credit balance type concept representing a natural cash outflow in the reconciliation of net income (loss) to NetCashProvidedByUsedInOperatingActivities. A credit balance type concept should always be assigned a negative one (-1) calculation weight as it is a deduction from net income (loss) to reconcile to NetCashProvidedByUsedInOperatingActivities.UnrealizedGainLossOnSecurities has been incorrectly provided a positive one (+1) calculation weight in the extension taxonomy. Correct the calculation weight to negative one (-1) and input the value as a positive amount if it is a deduction of a non-cash income or gain, an increase in an asset, or a decrease in a liability. If the value is an add-back of a non-cash expense or loss, decrease in an asset, or an increase in a liability and UnrealizedGainLossOnSecurities is the correct concept, input a negative value. Rule Element Id: 7488. https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd 11614, 17780</Log>
    <Log type="Warning">[dqc-0043-Incorrect-Calculation-Weights-In-Operating-Cash-Flows] The concept UnrealizedGainLossOnInvestments is included in the calculation of NetCashProvidedByUsedInOperatingActivities.UnrealizedGainLossOnInvestments is a credit balance type concept representing a natural cash outflow in the reconciliation of net income (loss) to NetCashProvidedByUsedInOperatingActivities. A credit balance type concept should always be assigned a negative one (-1) calculation weight as it is a deduction from net income (loss) to reconcile to NetCashProvidedByUsedInOperatingActivities.UnrealizedGainLossOnInvestments has been incorrectly provided a positive one (+1) calculation weight in the extension taxonomy. Correct the calculation weight to negative one (-1) and input the value as a positive amount if it is a deduction of a non-cash income or gain, an increase in an asset, or a decrease in a liability. If the value is an add-back of a non-cash expense or loss, decrease in an asset, or an increase in a liability and UnrealizedGainLossOnInvestments is the correct concept, input a negative value. Rule Element Id: 7488. https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd 11614, 17767</Log>
    <Log type="Warning">[dqc-0043-Incorrect-Calculation-Weights-In-Operating-Cash-Flows] The concept PaymentsForProceedsFromInvestments is included in the calculation of NetCashProvidedByUsedInOperatingActivities.PaymentsForProceedsFromInvestments is a credit balance type concept representing a natural cash outflow in the reconciliation of net income (loss) to NetCashProvidedByUsedInOperatingActivities. A credit balance type concept should always be assigned a negative one (-1) calculation weight as it is a deduction from net income (loss) to reconcile to NetCashProvidedByUsedInOperatingActivities.PaymentsForProceedsFromInvestments has been incorrectly provided a positive one (+1) calculation weight in the extension taxonomy. Correct the calculation weight to negative one (-1) and input the value as a positive amount if it is a deduction of a non-cash income or gain, an increase in an asset, or a decrease in a liability. If the value is an add-back of a non-cash expense or loss, decrease in an asset, or an increase in a liability and PaymentsForProceedsFromInvestments is the correct concept, input a negative value. Rule Element Id: 7488. https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd 11614, 13028</Log>
    <Log type="Warning">[dqc-0043-Incorrect-Calculation-Weights-In-Operating-Cash-Flows] The concept PaymentsForProceedsFromLoansReceivable is included in the calculation of NetCashProvidedByUsedInOperatingActivities.PaymentsForProceedsFromLoansReceivable is a credit balance type concept representing a natural cash outflow in the reconciliation of net income (loss) to NetCashProvidedByUsedInOperatingActivities. A credit balance type concept should always be assigned a negative one (-1) calculation weight as it is a deduction from net income (loss) to reconcile to NetCashProvidedByUsedInOperatingActivities.PaymentsForProceedsFromLoansReceivable has been incorrectly provided a positive one (+1) calculation weight in the extension taxonomy. Correct the calculation weight to negative one (-1) and input the value as a positive amount if it is a deduction of a non-cash income or gain, an increase in an asset, or a decrease in a liability. If the value is an add-back of a non-cash expense or loss, decrease in an asset, or an increase in a liability and PaymentsForProceedsFromLoansReceivable is the correct concept, input a negative value. Rule Element Id: 7488. https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd 11614, 13090</Log>
    <Log type="Warning">[dqc-0043-Incorrect-Calculation-Weights-In-Operating-Cash-Flows] The concept IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets is included in the calculation of NetCashProvidedByUsedInOperatingActivities.IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets is a credit balance type concept representing a natural cash outflow in the reconciliation of net income (loss) to NetCashProvidedByUsedInOperatingActivities. A credit balance type concept should always be assigned a negative one (-1) calculation weight as it is a deduction from net income (loss) to reconcile to NetCashProvidedByUsedInOperatingActivities.IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets has been incorrectly provided a positive one (+1) calculation weight in the extension taxonomy. Correct the calculation weight to negative one (-1) and input the value as a positive amount if it is a deduction of a non-cash income or gain, an increase in an asset, or a decrease in a liability. If the value is an add-back of a non-cash expense or loss, decrease in an asset, or an increase in a liability and IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets is the correct concept, input a negative value. Rule Element Id: 7488. https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd 8941, 11614</Log>
  </Logs>
  <InputFiles>
    <File doctype="10-Q" original="tfsa-20220930.htm">tfsa-20220930.htm</File>
    <File>a93022exhibit312.htm</File>
    <File>a93022exhibit32.htm</File>
    <File>a93122exhibit311.htm</File>
    <File>exhibit103eaglepoint-conse.htm</File>
    <File>exhibit35terramergersubllc.htm</File>
    <File>tfsa-20220930.xsd</File>
    <File>tfsa-20220930_cal.xml</File>
    <File>tfsa-20220930_def.xml</File>
    <File>tfsa-20220930_lab.xml</File>
    <File>tfsa-20220930_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy items="35">http://fasb.org/srt/2021-01-31</BaseTaxonomy>
    <BaseTaxonomy items="1179">http://fasb.org/us-gaap/2021-01-31</BaseTaxonomy>
    <BaseTaxonomy items="28">http://xbrl.sec.gov/dei/2021q4</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
