<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.20.4</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>452</ContextCount>
  <ElementCount>570</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>133</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>4</UnitCount>
  <MyReports>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>000010 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>000020 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_StatementConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>000030 - Statement - Consolidated Balance Sheets - Parenthetical</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_StatementConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets - Parenthetical</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>000040 - Statement - Consolidated Income Statement</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_StatementConsolidatedIncomeStatement</Role>
      <ShortName>Consolidated Income Statement</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>000050 - Statement - Consolidated Statement of Comprehensive Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_StatementConsolidatedStatementOfComprehensiveIncome</Role>
      <ShortName>Consolidated Statement of Comprehensive Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>000060 - Statement - Consolidated Statement of Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_StatementConsolidatedStatementOfStockholdersEquity</Role>
      <ShortName>Consolidated Statement of Stockholders' Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>000070 - Statement - Consolidated Statement of Stockholders' Equity - Parenthetical</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_StatementConsolidatedStatementOfStockholdersEquityParenthetical</Role>
      <ShortName>Consolidated Statement of Stockholders' Equity - Parenthetical</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>000080 - Statement - Consolidated Statement of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_StatementConsolidatedStatementOfCashFlows</Role>
      <ShortName>Consolidated Statement of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>000090 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>000100 - Disclosure - Earnings Per Share [Text Block]</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureEarningsPerShareTextBlock</Role>
      <ShortName>Earnings Per Share [Text Block]</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>000110 - Disclosure - Cash and Cash Equivalents Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCashAndCashEquivalentsDisclosure</Role>
      <ShortName>Cash and Cash Equivalents Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>000120 - Disclosure - Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock</Role>
      <ShortName>Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>000130 - Disclosure - Fair Value Disclosures [Text Block]</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureFairValueDisclosuresTextBlock</Role>
      <ShortName>Fair Value Disclosures [Text Block]</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>000140 - Disclosure - Investments in and Advances to Affiliates, Schedule of Investments [Text Block]</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInAndAdvancesToAffiliatesScheduleOfInvestmentsTextBlock</Role>
      <ShortName>Investments in and Advances to Affiliates, Schedule of Investments [Text Block]</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>000150 - Disclosure - Business Combination Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureBusinessCombinationDisclosure</Role>
      <ShortName>Business Combination Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>000160 - Disclosure - Goodwill and Intangible Assets Disclosure [Text Block]</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureGoodwillAndIntangibleAssetsDisclosureTextBlock</Role>
      <ShortName>Goodwill and Intangible Assets Disclosure [Text Block]</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>000170 - Disclosure - Lessee, Operating Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLesseeOperatingLeases</Role>
      <ShortName>Lessee, Operating Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>000180 - Disclosure - Reinsurance [Text Block]</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureReinsuranceTextBlock</Role>
      <ShortName>Reinsurance [Text Block]</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>000190 - Disclosure - Revenue from Contract with Customer</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureRevenueFromContractWithCustomer</Role>
      <ShortName>Revenue from Contract with Customer</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>000200 - Disclosure - Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlock</Role>
      <ShortName>Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>000210 - Disclosure - Income Tax Disclosure [Text Block]</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureIncomeTaxDisclosureTextBlock</Role>
      <ShortName>Income Tax Disclosure [Text Block]</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>000220 - Disclosure - Stockholders' Equity Note Disclosure [Text Block]</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureStockholdersEquityNoteDisclosureTextBlock</Role>
      <ShortName>Stockholders' Equity Note Disclosure [Text Block]</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>000230 - Disclosure - Compensation and Employee Benefit Plans [Text Block]</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCompensationAndEmployeeBenefitPlansTextBlock</Role>
      <ShortName>Compensation and Employee Benefit Plans [Text Block]</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>000240 - Disclosure - Contingencies Disclosure [Text Block]</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureContingenciesDisclosureTextBlock</Role>
      <ShortName>Contingencies Disclosure [Text Block]</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>000250 - Disclosure - Concentration Risk Disclosure [Text Block]</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureConcentrationRiskDisclosureTextBlock</Role>
      <ShortName>Concentration Risk Disclosure [Text Block]</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>000260 - Disclosure - Dividend Payment Restrictions [Text Block]</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureDividendPaymentRestrictionsTextBlock</Role>
      <ShortName>Dividend Payment Restrictions [Text Block]</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>000270 - Disclosure - Segment Reporting Disclosure [Text Block]</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureSegmentReportingDisclosureTextBlock</Role>
      <ShortName>Segment Reporting Disclosure [Text Block]</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>000280 - Disclosure - Summary of Investments, Other than Investments in Related Parties</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureSummaryOfInvestmentsOtherThanInvestmentsInRelatedParties</Role>
      <ShortName>Summary of Investments, Other than Investments in Related Parties</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>000290 - Disclosure - Condensed Financial Information of Parent Company Only Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCondensedFinancialInformationOfParentCompanyOnlyDisclosure</Role>
      <ShortName>Condensed Financial Information of Parent Company Only Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>000300 - Disclosure - Supplementary Insurance Information, for Insurance Companies Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureSupplementaryInsuranceInformationForInsuranceCompaniesDisclosure</Role>
      <ShortName>Supplementary Insurance Information, for Insurance Companies Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>000310 - Disclosure - Supplemental Schedule of Reinsurance Premiums for Insurance Companies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureSupplementalScheduleOfReinsurancePremiumsForInsuranceCompanies</Role>
      <ShortName>Supplemental Schedule of Reinsurance Premiums for Insurance Companies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>000320 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Basis of Accounting, Policy (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockBasisOfAccountingPolicyPolicies</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Basis of Accounting, Policy (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>000330 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Reclassification, Policy [Policy Text Block] (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockReclassificationPolicyPolicyTextBlockPolicies</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Reclassification, Policy [Policy Text Block] (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>000340 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Cash and Cash Equivalents, Policy (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockCashAndCashEquivalentsPolicyPolicies</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Cash and Cash Equivalents, Policy (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>000350 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Repurchase and Resale Agreements Policy (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockRepurchaseAndResaleAgreementsPolicyPolicies</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Repurchase and Resale Agreements Policy (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>000360 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Investment, Policy (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockInvestmentPolicyPolicies</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Investment, Policy (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>000370 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Property, Plant and Equipment, Policy (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockPropertyPlantAndEquipmentPolicyPolicies</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Property, Plant and Equipment, Policy (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>000380 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Goodwill and Intangible Assets, Policy (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockGoodwillAndIntangibleAssetsPolicyPolicies</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Goodwill and Intangible Assets, Policy (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>000390 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Unpaid Policy Claims and Claims Adjustment Expense, Policy (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockUnpaidPolicyClaimsAndClaimsAdjustmentExpensePolicyPolicies</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Unpaid Policy Claims and Claims Adjustment Expense, Policy (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>000400 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Future Policy Benefits Liability, Policy (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockFuturePolicyBenefitsLiabilityPolicyPolicies</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Future Policy Benefits Liability, Policy (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>000410 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Deposit Contracts, Policy (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockDepositContractsPolicyPolicies</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Deposit Contracts, Policy (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>000420 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Other Policyholders' Funds, Policy (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockOtherPolicyholdersFundsPolicyPolicies</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Other Policyholders' Funds, Policy (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>000430 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Income Tax, Policy (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockIncomeTaxPolicyPolicies</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Income Tax, Policy (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>000440 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Reinsurance Accounting Policy (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockReinsuranceAccountingPolicyPolicies</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Reinsurance Accounting Policy (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>000450 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Insurance Premiums Revenue Recognition, Policy (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockInsurancePremiumsRevenueRecognitionPolicyPolicies</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Insurance Premiums Revenue Recognition, Policy (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>000460 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Revenue from Contract with Customer (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockRevenueFromContractWithCustomerPolicies</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Revenue from Contract with Customer (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>000470 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Earnings Per Share, Policy (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockEarningsPerSharePolicyPolicies</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Earnings Per Share, Policy (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>000480 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Share-based Compensation, Option and Incentive Plans Policy (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockShareBasedCompensationOptionAndIncentivePlansPolicyPolicies</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Share-based Compensation, Option and Incentive Plans Policy (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>000490 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: New Accounting Pronouncements, Policy (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockNewAccountingPronouncementsPolicyPolicies</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: New Accounting Pronouncements, Policy (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>000500 - Disclosure - Cash and Cash Equivalents Disclosure: Schedule of Cash and Cash Equivalents (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCashAndCashEquivalentsDisclosureScheduleOfCashAndCashEquivalentsTables</Role>
      <ShortName>Cash and Cash Equivalents Disclosure: Schedule of Cash and Cash Equivalents (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>000510 - Disclosure - Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Debt Securities, Available-for-sale [Table Text Block] (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockDebtSecuritiesAvailableForSaleTableTextBlockTables</Role>
      <ShortName>Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Debt Securities, Available-for-sale [Table Text Block] (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>000520 - Disclosure - Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Investments Classified by Contractual Maturity Date (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockInvestmentsClassifiedByContractualMaturityDateTables</Role>
      <ShortName>Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Investments Classified by Contractual Maturity Date (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock</ParentRole>
      <Position>52</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>000530 - Disclosure - Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockAvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValueTables</Role>
      <ShortName>Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock</ParentRole>
      <Position>53</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>000540 - Disclosure - Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Investment Income (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockInvestmentIncomeTables</Role>
      <ShortName>Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Investment Income (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>000550 - Disclosure - Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Realized Gain (Loss) on Investments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockRealizedGainLossOnInvestmentsTables</Role>
      <ShortName>Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Realized Gain (Loss) on Investments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>000560 - Disclosure - Fair Value Disclosures [Text Block]: Fair Value, Assets Measured on Recurring Basis (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureFairValueDisclosuresTextBlockFairValueAssetsMeasuredOnRecurringBasisTables</Role>
      <ShortName>Fair Value Disclosures [Text Block]: Fair Value, Assets Measured on Recurring Basis (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>000570 - Disclosure - Fair Value Disclosures [Text Block]: Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureFairValueDisclosuresTextBlockFairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTables</Role>
      <ShortName>Fair Value Disclosures [Text Block]: Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>000580 - Disclosure - Fair Value Disclosures [Text Block]: Fair Value, by Balance Sheet Grouping (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureFairValueDisclosuresTextBlockFairValueByBalanceSheetGroupingTables</Role>
      <ShortName>Fair Value Disclosures [Text Block]: Fair Value, by Balance Sheet Grouping (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>000590 - Disclosure - Investments in and Advances to Affiliates, Schedule of Investments [Text Block]: Other Investments, Including Variable Interest Entities Table Text Block (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInAndAdvancesToAffiliatesScheduleOfInvestmentsTextBlockOtherInvestmentsIncludingVariableInterestEntitiesTableTextBlockTables</Role>
      <ShortName>Investments in and Advances to Affiliates, Schedule of Investments [Text Block]: Other Investments, Including Variable Interest Entities Table Text Block (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>000600 - Disclosure - Business Combination Disclosure: Schedule of Recognized Identified Assets Acquired and Liabilities Assumed (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureBusinessCombinationDisclosureScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTables</Role>
      <ShortName>Business Combination Disclosure: Schedule of Recognized Identified Assets Acquired and Liabilities Assumed (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>000610 - Disclosure - Goodwill and Intangible Assets Disclosure [Text Block]: Schedule of Goodwill [Table Text Block] (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureGoodwillAndIntangibleAssetsDisclosureTextBlockScheduleOfGoodwillTableTextBlockTables</Role>
      <ShortName>Goodwill and Intangible Assets Disclosure [Text Block]: Schedule of Goodwill [Table Text Block] (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>000620 - Disclosure - Goodwill and Intangible Assets Disclosure [Text Block]: Schedule of Finite-Lived Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureGoodwillAndIntangibleAssetsDisclosureTextBlockScheduleOfFiniteLivedIntangibleAssetsTables</Role>
      <ShortName>Goodwill and Intangible Assets Disclosure [Text Block]: Schedule of Finite-Lived Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>000630 - Disclosure - Goodwill and Intangible Assets Disclosure [Text Block]: Schedule of Indefinite-Lived Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureGoodwillAndIntangibleAssetsDisclosureTextBlockScheduleOfIndefiniteLivedIntangibleAssetsTables</Role>
      <ShortName>Goodwill and Intangible Assets Disclosure [Text Block]: Schedule of Indefinite-Lived Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>000640 - Disclosure - Goodwill and Intangible Assets Disclosure [Text Block]: Schedule of Finite-Lived Intangible Assets, Future Amortization Expense (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureGoodwillAndIntangibleAssetsDisclosureTextBlockScheduleOfFiniteLivedIntangibleAssetsFutureAmortizationExpenseTables</Role>
      <ShortName>Goodwill and Intangible Assets Disclosure [Text Block]: Schedule of Finite-Lived Intangible Assets, Future Amortization Expense (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>000650 - Disclosure - Lessee, Operating Leases: Lease, Cost (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLesseeOperatingLeasesLeaseCostTables</Role>
      <ShortName>Lessee, Operating Leases: Lease, Cost (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>000660 - Disclosure - Lessee, Operating Leases: Lessee, Operating Lease, Liability, Maturity (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLesseeOperatingLeasesLesseeOperatingLeaseLiabilityMaturityTables</Role>
      <ShortName>Lessee, Operating Leases: Lessee, Operating Lease, Liability, Maturity (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>000670 - Disclosure - Reinsurance [Text Block]: Effects of Reinsurance (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureReinsuranceTextBlockEffectsOfReinsuranceTables</Role>
      <ShortName>Reinsurance [Text Block]: Effects of Reinsurance (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>000680 - Disclosure - Revenue from Contract with Customer: Disaggregation of Revenue (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureRevenueFromContractWithCustomerDisaggregationOfRevenueTables</Role>
      <ShortName>Revenue from Contract with Customer: Disaggregation of Revenue (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>000690 - Disclosure - Revenue from Contract with Customer: Contract with Customer, Contract Asset, Contract Liability, and Receivable (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureRevenueFromContractWithCustomerContractWithCustomerContractAssetContractLiabilityAndReceivableTables</Role>
      <ShortName>Revenue from Contract with Customer: Contract with Customer, Contract Asset, Contract Liability, and Receivable (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>000700 - Disclosure - Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Schedule of Liability for Unpaid Claims and Claims Adjustment Expense (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockScheduleOfLiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseTables</Role>
      <ShortName>Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Schedule of Liability for Unpaid Claims and Claims Adjustment Expense (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>000710 - Disclosure - Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Schedule Of Prior Year Claims And Claims Adjustment Expense Disclosure (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockScheduleOfPriorYearClaimsAndClaimsAdjustmentExpenseDisclosureTables</Role>
      <ShortName>Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Schedule Of Prior Year Claims And Claims Adjustment Expense Disclosure (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>000720 - Disclosure - Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Short-duration Insurance Contracts, Claims Development (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockShortDurationInsuranceContractsClaimsDevelopmentTables</Role>
      <ShortName>Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Short-duration Insurance Contracts, Claims Development (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>000730 - Disclosure - Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Short-duration Insurance Contracts, Schedule of Historical Claims Duration (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockShortDurationInsuranceContractsScheduleOfHistoricalClaimsDurationTables</Role>
      <ShortName>Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Short-duration Insurance Contracts, Schedule of Historical Claims Duration (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>000740 - Disclosure - Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Short Duration Insurance Contracts, Discounted Liabilities Table Text Block (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockShortDurationInsuranceContractsDiscountedLiabilitiesTableTextBlockTables</Role>
      <ShortName>Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Short Duration Insurance Contracts, Discounted Liabilities Table Text Block (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>000750 - Disclosure - Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockShortDurationInsuranceContractsReconciliationOfClaimsDevelopmentToLiabilityTables</Role>
      <ShortName>Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>000760 - Disclosure - Income Tax Disclosure [Text Block]: Schedule of Components of Income Tax Expense (Benefit) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureIncomeTaxDisclosureTextBlockScheduleOfComponentsOfIncomeTaxExpenseBenefitTables</Role>
      <ShortName>Income Tax Disclosure [Text Block]: Schedule of Components of Income Tax Expense (Benefit) (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>000770 - Disclosure - Income Tax Disclosure [Text Block]: Schedule of Effective Income Tax Rate Reconciliation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureIncomeTaxDisclosureTextBlockScheduleOfEffectiveIncomeTaxRateReconciliationTables</Role>
      <ShortName>Income Tax Disclosure [Text Block]: Schedule of Effective Income Tax Rate Reconciliation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>000780 - Disclosure - Income Tax Disclosure [Text Block]: Schedule of Deferred Tax Assets and Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureIncomeTaxDisclosureTextBlockScheduleOfDeferredTaxAssetsAndLiabilitiesTables</Role>
      <ShortName>Income Tax Disclosure [Text Block]: Schedule of Deferred Tax Assets and Liabilities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>000790 - Disclosure - Stockholders' Equity Note Disclosure [Text Block]: Schedule of Accumulated Other Comprehensive Income (Loss) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureStockholdersEquityNoteDisclosureTextBlockScheduleOfAccumulatedOtherComprehensiveIncomeLossTables</Role>
      <ShortName>Stockholders' Equity Note Disclosure [Text Block]: Schedule of Accumulated Other Comprehensive Income (Loss) (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>79</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>000800 - Disclosure - Stockholders' Equity Note Disclosure [Text Block]: Reclassification out of Accumulated Other Comprehensive Income (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureStockholdersEquityNoteDisclosureTextBlockReclassificationOutOfAccumulatedOtherComprehensiveIncomeTables</Role>
      <ShortName>Stockholders' Equity Note Disclosure [Text Block]: Reclassification out of Accumulated Other Comprehensive Income (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>80</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>000810 - Disclosure - Compensation and Employee Benefit Plans [Text Block]: Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCompensationAndEmployeeBenefitPlansTextBlockScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTables</Role>
      <ShortName>Compensation and Employee Benefit Plans [Text Block]: Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>81</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>000820 - Disclosure - Compensation and Employee Benefit Plans [Text Block]: Schedule of Share-based Compensation, Stock Options, Activity (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCompensationAndEmployeeBenefitPlansTextBlockScheduleOfShareBasedCompensationStockOptionsActivityTables</Role>
      <ShortName>Compensation and Employee Benefit Plans [Text Block]: Schedule of Share-based Compensation, Stock Options, Activity (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>82</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>000830 - Disclosure - Compensation and Employee Benefit Plans [Text Block]: Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCompensationAndEmployeeBenefitPlansTextBlockScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTables</Role>
      <ShortName>Compensation and Employee Benefit Plans [Text Block]: Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>83</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>000840 - Disclosure - Compensation and Employee Benefit Plans [Text Block]: Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCompensationAndEmployeeBenefitPlansTextBlockScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingTables</Role>
      <ShortName>Compensation and Employee Benefit Plans [Text Block]: Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>84</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>000850 - Disclosure - Compensation and Employee Benefit Plans [Text Block]: Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCompensationAndEmployeeBenefitPlansTextBlockShareBasedPaymentArrangementRestrictedStockAndRestrictedStockUnitActivityTables</Role>
      <ShortName>Compensation and Employee Benefit Plans [Text Block]: Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>85</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>000860 - Disclosure - Concentration Risk Disclosure [Text Block]: Ceded Credit Risk [Table Text Block] (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureConcentrationRiskDisclosureTextBlockCededCreditRiskTableTextBlockTables</Role>
      <ShortName>Concentration Risk Disclosure [Text Block]: Ceded Credit Risk [Table Text Block] (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>86</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>000870 - Disclosure - Dividend Payment Restrictions [Text Block]: Statutory Accounting Practices Disclosure (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureDividendPaymentRestrictionsTextBlockStatutoryAccountingPracticesDisclosureTables</Role>
      <ShortName>Dividend Payment Restrictions [Text Block]: Statutory Accounting Practices Disclosure (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>87</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>000880 - Disclosure - Segment Reporting Disclosure [Text Block]: Schedule of Segment Reporting Information, by Segment (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureSegmentReportingDisclosureTextBlockScheduleOfSegmentReportingInformationBySegmentTables</Role>
      <ShortName>Segment Reporting Disclosure [Text Block]: Schedule of Segment Reporting Information, by Segment (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>88</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>000890 - Disclosure - Summary of Investments, Other than Investments in Related Parties: Summary Of Investments Other Than Investments In Related Parties Table Text Block (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureSummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesSummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesTableTextBlockTables</Role>
      <ShortName>Summary of Investments, Other than Investments in Related Parties: Summary Of Investments Other Than Investments In Related Parties Table Text Block (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>89</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>000900 - Disclosure - Condensed Financial Information of Parent Company Only Disclosure: Condensed Balance Sheet (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCondensedFinancialInformationOfParentCompanyOnlyDisclosureCondensedBalanceSheetTables</Role>
      <ShortName>Condensed Financial Information of Parent Company Only Disclosure: Condensed Balance Sheet (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>90</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>000910 - Disclosure - Condensed Financial Information of Parent Company Only Disclosure: Condensed Income Statement (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCondensedFinancialInformationOfParentCompanyOnlyDisclosureCondensedIncomeStatementTables</Role>
      <ShortName>Condensed Financial Information of Parent Company Only Disclosure: Condensed Income Statement (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>91</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R92.htm</HtmlFileName>
      <LongName>000920 - Disclosure - Condensed Financial Information of Parent Company Only Disclosure: Condensed Cash Flow Statement (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCondensedFinancialInformationOfParentCompanyOnlyDisclosureCondensedCashFlowStatementTables</Role>
      <ShortName>Condensed Financial Information of Parent Company Only Disclosure: Condensed Cash Flow Statement (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>92</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R93.htm</HtmlFileName>
      <LongName>000930 - Disclosure - Supplementary Insurance Information, for Insurance Companies Disclosure: Supplementary Insurance Information For Insurance Companies Disclosure Table Text Block (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureSupplementaryInsuranceInformationForInsuranceCompaniesDisclosureSupplementaryInsuranceInformationForInsuranceCompaniesDisclosureTableTextBlockTables</Role>
      <ShortName>Supplementary Insurance Information, for Insurance Companies Disclosure: Supplementary Insurance Information For Insurance Companies Disclosure Table Text Block (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>93</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R94.htm</HtmlFileName>
      <LongName>000940 - Disclosure - Supplemental Schedule of Reinsurance Premiums for Insurance Companies: Supplemental Schedule Of Reinsurance Premiums For Insurance Companies Table Text Block (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureSupplementalScheduleOfReinsurancePremiumsForInsuranceCompaniesSupplementalScheduleOfReinsurancePremiumsForInsuranceCompaniesTableTextBlockTables</Role>
      <ShortName>Supplemental Schedule of Reinsurance Premiums for Insurance Companies: Supplemental Schedule Of Reinsurance Premiums For Insurance Companies Table Text Block (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>94</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R95.htm</HtmlFileName>
      <LongName>000950 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockDetails</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockBasisOfAccountingPolicyPolicies</ParentRole>
      <Position>95</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R96.htm</HtmlFileName>
      <LongName>000960 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Repurchase and Resale Agreements Policy (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockRepurchaseAndResaleAgreementsPolicyDetails</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Repurchase and Resale Agreements Policy (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockRepurchaseAndResaleAgreementsPolicyPolicies</ParentRole>
      <Position>96</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R97.htm</HtmlFileName>
      <LongName>000970 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Property, Plant and Equipment, Policy (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockPropertyPlantAndEquipmentPolicyDetails</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Property, Plant and Equipment, Policy (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockPropertyPlantAndEquipmentPolicyPolicies</ParentRole>
      <Position>97</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R98.htm</HtmlFileName>
      <LongName>000980 - Disclosure - Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Deposit Contracts, Policy (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockDepositContractsPolicyDetails</Role>
      <ShortName>Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]: Deposit Contracts, Policy (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureOrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlockBasisOfAccountingPolicyPolicies</ParentRole>
      <Position>98</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R99.htm</HtmlFileName>
      <LongName>000990 - Disclosure - Earnings Per Share [Text Block] (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureEarningsPerShareTextBlockDetails</Role>
      <ShortName>Earnings Per Share [Text Block] (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureEarningsPerShareTextBlock</ParentRole>
      <Position>99</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R100.htm</HtmlFileName>
      <LongName>001000 - Disclosure - Cash and Cash Equivalents Disclosure: Schedule of Cash and Cash Equivalents (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCashAndCashEquivalentsDisclosureScheduleOfCashAndCashEquivalentsDetails</Role>
      <ShortName>Cash and Cash Equivalents Disclosure: Schedule of Cash and Cash Equivalents (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureCashAndCashEquivalentsDisclosureScheduleOfCashAndCashEquivalentsTables</ParentRole>
      <Position>100</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R101.htm</HtmlFileName>
      <LongName>001010 - Disclosure - Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Debt Securities, Available-for-sale [Table Text Block] (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockDebtSecuritiesAvailableForSaleTableTextBlockDetails</Role>
      <ShortName>Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Debt Securities, Available-for-sale [Table Text Block] (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockDebtSecuritiesAvailableForSaleTableTextBlockTables</ParentRole>
      <Position>101</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R102.htm</HtmlFileName>
      <LongName>001020 - Disclosure - Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Investments Classified by Contractual Maturity Date (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockInvestmentsClassifiedByContractualMaturityDateDetails</Role>
      <ShortName>Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Investments Classified by Contractual Maturity Date (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockDebtSecuritiesAvailableForSaleTableTextBlockTables</ParentRole>
      <Position>102</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R103.htm</HtmlFileName>
      <LongName>001030 - Disclosure - Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockAvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValueDetails</Role>
      <ShortName>Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockDebtSecuritiesAvailableForSaleTableTextBlockTables</ParentRole>
      <Position>103</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R104.htm</HtmlFileName>
      <LongName>001040 - Disclosure - Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Investment Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockInvestmentIncomeDetails</Role>
      <ShortName>Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Investment Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockDebtSecuritiesAvailableForSaleTableTextBlockTables</ParentRole>
      <Position>104</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R105.htm</HtmlFileName>
      <LongName>001050 - Disclosure - Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Realized Gain (Loss) on Investments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockRealizedGainLossOnInvestmentsDetails</Role>
      <ShortName>Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Realized Gain (Loss) on Investments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockDebtSecuritiesAvailableForSaleTableTextBlockTables</ParentRole>
      <Position>105</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R106.htm</HtmlFileName>
      <LongName>001060 - Disclosure - Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockDetails</Role>
      <ShortName>Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlockDebtSecuritiesAvailableForSaleTableTextBlockTables</ParentRole>
      <Position>106</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R107.htm</HtmlFileName>
      <LongName>001070 - Disclosure - Fair Value Disclosures [Text Block]: Fair Value, Assets Measured on Recurring Basis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureFairValueDisclosuresTextBlockFairValueAssetsMeasuredOnRecurringBasisDetails</Role>
      <ShortName>Fair Value Disclosures [Text Block]: Fair Value, Assets Measured on Recurring Basis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureFairValueDisclosuresTextBlockFairValueAssetsMeasuredOnRecurringBasisTables</ParentRole>
      <Position>107</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R108.htm</HtmlFileName>
      <LongName>001080 - Disclosure - Fair Value Disclosures [Text Block]: Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureFairValueDisclosuresTextBlockFairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationDetails</Role>
      <ShortName>Fair Value Disclosures [Text Block]: Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureFairValueDisclosuresTextBlockFairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTables</ParentRole>
      <Position>108</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R109.htm</HtmlFileName>
      <LongName>001090 - Disclosure - Fair Value Disclosures [Text Block] (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureFairValueDisclosuresTextBlockDetails</Role>
      <ShortName>Fair Value Disclosures [Text Block] (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureFairValueDisclosuresTextBlockFairValueAssetsMeasuredOnRecurringBasisTables</ParentRole>
      <Position>109</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R110.htm</HtmlFileName>
      <LongName>001100 - Disclosure - Fair Value Disclosures [Text Block]: Fair Value, by Balance Sheet Grouping (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureFairValueDisclosuresTextBlockFairValueByBalanceSheetGroupingDetails</Role>
      <ShortName>Fair Value Disclosures [Text Block]: Fair Value, by Balance Sheet Grouping (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureFairValueDisclosuresTextBlockFairValueByBalanceSheetGroupingTables</ParentRole>
      <Position>110</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R111.htm</HtmlFileName>
      <LongName>001110 - Disclosure - Investments in and Advances to Affiliates, Schedule of Investments [Text Block]: Other Investments, Including Variable Interest Entities Table Text Block (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInAndAdvancesToAffiliatesScheduleOfInvestmentsTextBlockOtherInvestmentsIncludingVariableInterestEntitiesTableTextBlockDetails</Role>
      <ShortName>Investments in and Advances to Affiliates, Schedule of Investments [Text Block]: Other Investments, Including Variable Interest Entities Table Text Block (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInAndAdvancesToAffiliatesScheduleOfInvestmentsTextBlockOtherInvestmentsIncludingVariableInterestEntitiesTableTextBlockTables</ParentRole>
      <Position>111</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R112.htm</HtmlFileName>
      <LongName>001120 - Disclosure - Investments in and Advances to Affiliates, Schedule of Investments [Text Block] (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInAndAdvancesToAffiliatesScheduleOfInvestmentsTextBlockDetails</Role>
      <ShortName>Investments in and Advances to Affiliates, Schedule of Investments [Text Block] (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureInvestmentsInAndAdvancesToAffiliatesScheduleOfInvestmentsTextBlockOtherInvestmentsIncludingVariableInterestEntitiesTableTextBlockTables</ParentRole>
      <Position>112</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R113.htm</HtmlFileName>
      <LongName>001130 - Disclosure - Business Combination Disclosure (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureBusinessCombinationDisclosureDetails</Role>
      <ShortName>Business Combination Disclosure (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureBusinessCombinationDisclosureScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTables</ParentRole>
      <Position>113</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R114.htm</HtmlFileName>
      <LongName>001140 - Disclosure - Business Combination Disclosure: Schedule of Recognized Identified Assets Acquired and Liabilities Assumed (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureBusinessCombinationDisclosureScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedDetails</Role>
      <ShortName>Business Combination Disclosure: Schedule of Recognized Identified Assets Acquired and Liabilities Assumed (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureBusinessCombinationDisclosureScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTables</ParentRole>
      <Position>114</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R115.htm</HtmlFileName>
      <LongName>001150 - Disclosure - Goodwill and Intangible Assets Disclosure [Text Block]: Schedule of Goodwill [Table Text Block] (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureGoodwillAndIntangibleAssetsDisclosureTextBlockScheduleOfGoodwillTableTextBlockDetails</Role>
      <ShortName>Goodwill and Intangible Assets Disclosure [Text Block]: Schedule of Goodwill [Table Text Block] (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureGoodwillAndIntangibleAssetsDisclosureTextBlockScheduleOfGoodwillTableTextBlockTables</ParentRole>
      <Position>115</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R116.htm</HtmlFileName>
      <LongName>001160 - Disclosure - Goodwill and Intangible Assets Disclosure [Text Block] (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureGoodwillAndIntangibleAssetsDisclosureTextBlockDetails</Role>
      <ShortName>Goodwill and Intangible Assets Disclosure [Text Block] (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureGoodwillAndIntangibleAssetsDisclosureTextBlockScheduleOfGoodwillTableTextBlockTables</ParentRole>
      <Position>116</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R117.htm</HtmlFileName>
      <LongName>001170 - Disclosure - Goodwill and Intangible Assets Disclosure [Text Block]: Schedule of Finite-Lived Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureGoodwillAndIntangibleAssetsDisclosureTextBlockScheduleOfFiniteLivedIntangibleAssetsDetails</Role>
      <ShortName>Goodwill and Intangible Assets Disclosure [Text Block]: Schedule of Finite-Lived Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureGoodwillAndIntangibleAssetsDisclosureTextBlockScheduleOfFiniteLivedIntangibleAssetsTables</ParentRole>
      <Position>117</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R118.htm</HtmlFileName>
      <LongName>001180 - Disclosure - Goodwill and Intangible Assets Disclosure [Text Block]: Schedule of Indefinite-Lived Intangible Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureGoodwillAndIntangibleAssetsDisclosureTextBlockScheduleOfIndefiniteLivedIntangibleAssetsDetails</Role>
      <ShortName>Goodwill and Intangible Assets Disclosure [Text Block]: Schedule of Indefinite-Lived Intangible Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureGoodwillAndIntangibleAssetsDisclosureTextBlockScheduleOfIndefiniteLivedIntangibleAssetsTables</ParentRole>
      <Position>118</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R119.htm</HtmlFileName>
      <LongName>001190 - Disclosure - Goodwill and Intangible Assets Disclosure [Text Block]: Schedule of Finite-Lived Intangible Assets, Future Amortization Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureGoodwillAndIntangibleAssetsDisclosureTextBlockScheduleOfFiniteLivedIntangibleAssetsFutureAmortizationExpenseDetails</Role>
      <ShortName>Goodwill and Intangible Assets Disclosure [Text Block]: Schedule of Finite-Lived Intangible Assets, Future Amortization Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureGoodwillAndIntangibleAssetsDisclosureTextBlockScheduleOfFiniteLivedIntangibleAssetsFutureAmortizationExpenseTables</ParentRole>
      <Position>119</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R120.htm</HtmlFileName>
      <LongName>001200 - Disclosure - Lessee, Operating Leases (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLesseeOperatingLeasesDetails</Role>
      <ShortName>Lessee, Operating Leases (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureLesseeOperatingLeasesLeaseCostTables</ParentRole>
      <Position>120</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R121.htm</HtmlFileName>
      <LongName>001210 - Disclosure - Lessee, Operating Leases: Lease, Cost (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLesseeOperatingLeasesLeaseCostDetails</Role>
      <ShortName>Lessee, Operating Leases: Lease, Cost (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureLesseeOperatingLeasesLeaseCostTables</ParentRole>
      <Position>121</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R122.htm</HtmlFileName>
      <LongName>001220 - Disclosure - Lessee, Operating Leases: Lessee, Operating Lease, Liability, Maturity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLesseeOperatingLeasesLesseeOperatingLeaseLiabilityMaturityDetails</Role>
      <ShortName>Lessee, Operating Leases: Lessee, Operating Lease, Liability, Maturity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureLesseeOperatingLeasesLesseeOperatingLeaseLiabilityMaturityTables</ParentRole>
      <Position>122</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R123.htm</HtmlFileName>
      <LongName>001230 - Disclosure - Reinsurance [Text Block]: Effects of Reinsurance (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureReinsuranceTextBlockEffectsOfReinsuranceDetails</Role>
      <ShortName>Reinsurance [Text Block]: Effects of Reinsurance (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureReinsuranceTextBlockEffectsOfReinsuranceTables</ParentRole>
      <Position>123</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R124.htm</HtmlFileName>
      <LongName>001240 - Disclosure - Revenue from Contract with Customer: Disaggregation of Revenue (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureRevenueFromContractWithCustomerDisaggregationOfRevenueDetails</Role>
      <ShortName>Revenue from Contract with Customer: Disaggregation of Revenue (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureRevenueFromContractWithCustomerDisaggregationOfRevenueTables</ParentRole>
      <Position>124</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R125.htm</HtmlFileName>
      <LongName>001250 - Disclosure - Revenue from Contract with Customer (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureRevenueFromContractWithCustomerDetails</Role>
      <ShortName>Revenue from Contract with Customer (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureRevenueFromContractWithCustomerDisaggregationOfRevenueTables</ParentRole>
      <Position>125</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R126.htm</HtmlFileName>
      <LongName>001260 - Disclosure - Revenue from Contract with Customer: Contract with Customer, Contract Asset, Contract Liability, and Receivable (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureRevenueFromContractWithCustomerContractWithCustomerContractAssetContractLiabilityAndReceivableDetails</Role>
      <ShortName>Revenue from Contract with Customer: Contract with Customer, Contract Asset, Contract Liability, and Receivable (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureRevenueFromContractWithCustomerContractWithCustomerContractAssetContractLiabilityAndReceivableTables</ParentRole>
      <Position>126</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R127.htm</HtmlFileName>
      <LongName>001270 - Disclosure - Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Schedule of Liability for Unpaid Claims and Claims Adjustment Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockScheduleOfLiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseDetails</Role>
      <ShortName>Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Schedule of Liability for Unpaid Claims and Claims Adjustment Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockScheduleOfLiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseTables</ParentRole>
      <Position>127</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R128.htm</HtmlFileName>
      <LongName>001280 - Disclosure - Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Schedule Of Prior Year Claims And Claims Adjustment Expense Disclosure (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockScheduleOfPriorYearClaimsAndClaimsAdjustmentExpenseDisclosureDetails</Role>
      <ShortName>Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Schedule Of Prior Year Claims And Claims Adjustment Expense Disclosure (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockScheduleOfPriorYearClaimsAndClaimsAdjustmentExpenseDisclosureTables</ParentRole>
      <Position>128</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R129.htm</HtmlFileName>
      <LongName>001290 - Disclosure - Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block] (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockDetails</Role>
      <ShortName>Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block] (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockScheduleOfLiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseTables</ParentRole>
      <Position>129</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R130.htm</HtmlFileName>
      <LongName>001300 - Disclosure - Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Short-duration Insurance Contracts, Claims Development (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockShortDurationInsuranceContractsClaimsDevelopmentDetails</Role>
      <ShortName>Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Short-duration Insurance Contracts, Claims Development (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockShortDurationInsuranceContractsClaimsDevelopmentTables</ParentRole>
      <Position>130</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R131.htm</HtmlFileName>
      <LongName>001310 - Disclosure - Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Short-duration Insurance Contracts, Schedule of Historical Claims Duration (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockShortDurationInsuranceContractsScheduleOfHistoricalClaimsDurationDetails</Role>
      <ShortName>Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Short-duration Insurance Contracts, Schedule of Historical Claims Duration (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockShortDurationInsuranceContractsScheduleOfHistoricalClaimsDurationTables</ParentRole>
      <Position>131</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R132.htm</HtmlFileName>
      <LongName>001320 - Disclosure - Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Short Duration Insurance Contracts, Discounted Liabilities Table Text Block (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockShortDurationInsuranceContractsDiscountedLiabilitiesTableTextBlockDetails</Role>
      <ShortName>Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Short Duration Insurance Contracts, Discounted Liabilities Table Text Block (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockShortDurationInsuranceContractsDiscountedLiabilitiesTableTextBlockTables</ParentRole>
      <Position>132</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R133.htm</HtmlFileName>
      <LongName>001330 - Disclosure - Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockShortDurationInsuranceContractsReconciliationOfClaimsDevelopmentToLiabilityDetails</Role>
      <ShortName>Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]: Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureLiabilityForFuturePolicyBenefitsAndUnpaidClaimsDisclosureTextBlockShortDurationInsuranceContractsReconciliationOfClaimsDevelopmentToLiabilityTables</ParentRole>
      <Position>133</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R134.htm</HtmlFileName>
      <LongName>001340 - Disclosure - Income Tax Disclosure [Text Block]: Schedule of Components of Income Tax Expense (Benefit) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureIncomeTaxDisclosureTextBlockScheduleOfComponentsOfIncomeTaxExpenseBenefitDetails</Role>
      <ShortName>Income Tax Disclosure [Text Block]: Schedule of Components of Income Tax Expense (Benefit) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureIncomeTaxDisclosureTextBlockScheduleOfComponentsOfIncomeTaxExpenseBenefitTables</ParentRole>
      <Position>134</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R135.htm</HtmlFileName>
      <LongName>001350 - Disclosure - Income Tax Disclosure [Text Block] (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureIncomeTaxDisclosureTextBlockDetails</Role>
      <ShortName>Income Tax Disclosure [Text Block] (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureIncomeTaxDisclosureTextBlockScheduleOfComponentsOfIncomeTaxExpenseBenefitTables</ParentRole>
      <Position>135</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R136.htm</HtmlFileName>
      <LongName>001360 - Disclosure - Income Tax Disclosure [Text Block]: Schedule of Effective Income Tax Rate Reconciliation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureIncomeTaxDisclosureTextBlockScheduleOfEffectiveIncomeTaxRateReconciliationDetails</Role>
      <ShortName>Income Tax Disclosure [Text Block]: Schedule of Effective Income Tax Rate Reconciliation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureIncomeTaxDisclosureTextBlockScheduleOfEffectiveIncomeTaxRateReconciliationTables</ParentRole>
      <Position>136</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R137.htm</HtmlFileName>
      <LongName>001370 - Disclosure - Income Tax Disclosure [Text Block]: Schedule of Deferred Tax Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureIncomeTaxDisclosureTextBlockScheduleOfDeferredTaxAssetsAndLiabilitiesDetails</Role>
      <ShortName>Income Tax Disclosure [Text Block]: Schedule of Deferred Tax Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureIncomeTaxDisclosureTextBlockScheduleOfDeferredTaxAssetsAndLiabilitiesTables</ParentRole>
      <Position>137</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R138.htm</HtmlFileName>
      <LongName>001380 - Disclosure - Stockholders' Equity Note Disclosure [Text Block] (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureStockholdersEquityNoteDisclosureTextBlockDetails</Role>
      <ShortName>Stockholders' Equity Note Disclosure [Text Block] (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureStockholdersEquityNoteDisclosureTextBlockScheduleOfAccumulatedOtherComprehensiveIncomeLossTables</ParentRole>
      <Position>138</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R139.htm</HtmlFileName>
      <LongName>001390 - Disclosure - Stockholders' Equity Note Disclosure [Text Block]: Schedule of Accumulated Other Comprehensive Income (Loss) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureStockholdersEquityNoteDisclosureTextBlockScheduleOfAccumulatedOtherComprehensiveIncomeLossDetails</Role>
      <ShortName>Stockholders' Equity Note Disclosure [Text Block]: Schedule of Accumulated Other Comprehensive Income (Loss) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureStockholdersEquityNoteDisclosureTextBlockScheduleOfAccumulatedOtherComprehensiveIncomeLossTables</ParentRole>
      <Position>139</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R140.htm</HtmlFileName>
      <LongName>001400 - Disclosure - Stockholders' Equity Note Disclosure [Text Block]: Reclassification out of Accumulated Other Comprehensive Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureStockholdersEquityNoteDisclosureTextBlockReclassificationOutOfAccumulatedOtherComprehensiveIncomeDetails</Role>
      <ShortName>Stockholders' Equity Note Disclosure [Text Block]: Reclassification out of Accumulated Other Comprehensive Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureStockholdersEquityNoteDisclosureTextBlockReclassificationOutOfAccumulatedOtherComprehensiveIncomeTables</ParentRole>
      <Position>140</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R141.htm</HtmlFileName>
      <LongName>001410 - Disclosure - Compensation and Employee Benefit Plans [Text Block] (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCompensationAndEmployeeBenefitPlansTextBlockDetails</Role>
      <ShortName>Compensation and Employee Benefit Plans [Text Block] (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureCompensationAndEmployeeBenefitPlansTextBlockScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTables</ParentRole>
      <Position>141</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R142.htm</HtmlFileName>
      <LongName>001420 - Disclosure - Compensation and Employee Benefit Plans [Text Block]: Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCompensationAndEmployeeBenefitPlansTextBlockScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanDetails</Role>
      <ShortName>Compensation and Employee Benefit Plans [Text Block]: Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureCompensationAndEmployeeBenefitPlansTextBlockScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTables</ParentRole>
      <Position>142</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R143.htm</HtmlFileName>
      <LongName>001430 - Disclosure - Compensation and Employee Benefit Plans [Text Block]: Schedule of Share-based Compensation, Stock Options, Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCompensationAndEmployeeBenefitPlansTextBlockScheduleOfShareBasedCompensationStockOptionsActivityDetails</Role>
      <ShortName>Compensation and Employee Benefit Plans [Text Block]: Schedule of Share-based Compensation, Stock Options, Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureCompensationAndEmployeeBenefitPlansTextBlockScheduleOfShareBasedCompensationStockOptionsActivityTables</ParentRole>
      <Position>143</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R144.htm</HtmlFileName>
      <LongName>001440 - Disclosure - Compensation and Employee Benefit Plans [Text Block]: Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCompensationAndEmployeeBenefitPlansTextBlockScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsDetails</Role>
      <ShortName>Compensation and Employee Benefit Plans [Text Block]: Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureCompensationAndEmployeeBenefitPlansTextBlockScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTables</ParentRole>
      <Position>144</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R145.htm</HtmlFileName>
      <LongName>001450 - Disclosure - Compensation and Employee Benefit Plans [Text Block]: Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCompensationAndEmployeeBenefitPlansTextBlockScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingDetails</Role>
      <ShortName>Compensation and Employee Benefit Plans [Text Block]: Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureCompensationAndEmployeeBenefitPlansTextBlockScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingTables</ParentRole>
      <Position>145</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R146.htm</HtmlFileName>
      <LongName>001460 - Disclosure - Compensation and Employee Benefit Plans [Text Block]: Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCompensationAndEmployeeBenefitPlansTextBlockShareBasedPaymentArrangementRestrictedStockAndRestrictedStockUnitActivityDetails</Role>
      <ShortName>Compensation and Employee Benefit Plans [Text Block]: Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureCompensationAndEmployeeBenefitPlansTextBlockShareBasedPaymentArrangementRestrictedStockAndRestrictedStockUnitActivityTables</ParentRole>
      <Position>146</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R147.htm</HtmlFileName>
      <LongName>001470 - Disclosure - Contingencies Disclosure [Text Block] (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureContingenciesDisclosureTextBlockDetails</Role>
      <ShortName>Contingencies Disclosure [Text Block] (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureContingenciesDisclosureTextBlock</ParentRole>
      <Position>147</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R148.htm</HtmlFileName>
      <LongName>001480 - Disclosure - Concentration Risk Disclosure [Text Block] (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureConcentrationRiskDisclosureTextBlockDetails</Role>
      <ShortName>Concentration Risk Disclosure [Text Block] (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureConcentrationRiskDisclosureTextBlockCededCreditRiskTableTextBlockTables</ParentRole>
      <Position>148</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R149.htm</HtmlFileName>
      <LongName>001490 - Disclosure - Concentration Risk Disclosure [Text Block]: Ceded Credit Risk [Table Text Block] (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureConcentrationRiskDisclosureTextBlockCededCreditRiskTableTextBlockDetails</Role>
      <ShortName>Concentration Risk Disclosure [Text Block]: Ceded Credit Risk [Table Text Block] (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureConcentrationRiskDisclosureTextBlockCededCreditRiskTableTextBlockTables</ParentRole>
      <Position>149</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R150.htm</HtmlFileName>
      <LongName>001500 - Disclosure - Dividend Payment Restrictions [Text Block] (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureDividendPaymentRestrictionsTextBlockDetails</Role>
      <ShortName>Dividend Payment Restrictions [Text Block] (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureDividendPaymentRestrictionsTextBlockStatutoryAccountingPracticesDisclosureTables</ParentRole>
      <Position>150</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R151.htm</HtmlFileName>
      <LongName>001510 - Disclosure - Dividend Payment Restrictions [Text Block]: Statutory Accounting Practices Disclosure (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureDividendPaymentRestrictionsTextBlockStatutoryAccountingPracticesDisclosureDetails</Role>
      <ShortName>Dividend Payment Restrictions [Text Block]: Statutory Accounting Practices Disclosure (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureDividendPaymentRestrictionsTextBlockStatutoryAccountingPracticesDisclosureTables</ParentRole>
      <Position>151</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R152.htm</HtmlFileName>
      <LongName>001520 - Disclosure - Segment Reporting Disclosure [Text Block]: Schedule of Segment Reporting Information, by Segment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureSegmentReportingDisclosureTextBlockScheduleOfSegmentReportingInformationBySegmentDetails</Role>
      <ShortName>Segment Reporting Disclosure [Text Block]: Schedule of Segment Reporting Information, by Segment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureSegmentReportingDisclosureTextBlockScheduleOfSegmentReportingInformationBySegmentTables</ParentRole>
      <Position>152</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R153.htm</HtmlFileName>
      <LongName>001530 - Disclosure - Summary of Investments, Other than Investments in Related Parties: Summary Of Investments Other Than Investments In Related Parties Table Text Block (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureSummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesSummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesTableTextBlockDetails</Role>
      <ShortName>Summary of Investments, Other than Investments in Related Parties: Summary Of Investments Other Than Investments In Related Parties Table Text Block (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureSummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesSummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesTableTextBlockTables</ParentRole>
      <Position>153</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R154.htm</HtmlFileName>
      <LongName>001540 - Disclosure - Condensed Financial Information of Parent Company Only Disclosure: Condensed Balance Sheet (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCondensedFinancialInformationOfParentCompanyOnlyDisclosureCondensedBalanceSheetDetails</Role>
      <ShortName>Condensed Financial Information of Parent Company Only Disclosure: Condensed Balance Sheet (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureCondensedFinancialInformationOfParentCompanyOnlyDisclosureCondensedBalanceSheetTables</ParentRole>
      <Position>154</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R155.htm</HtmlFileName>
      <LongName>001550 - Disclosure - Condensed Financial Information of Parent Company Only Disclosure: Condensed Income Statement (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCondensedFinancialInformationOfParentCompanyOnlyDisclosureCondensedIncomeStatementDetails</Role>
      <ShortName>Condensed Financial Information of Parent Company Only Disclosure: Condensed Income Statement (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureCondensedFinancialInformationOfParentCompanyOnlyDisclosureCondensedBalanceSheetTables</ParentRole>
      <Position>155</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R156.htm</HtmlFileName>
      <LongName>001560 - Disclosure - Condensed Financial Information of Parent Company Only Disclosure: Condensed Cash Flow Statement (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureCondensedFinancialInformationOfParentCompanyOnlyDisclosureCondensedCashFlowStatementDetails</Role>
      <ShortName>Condensed Financial Information of Parent Company Only Disclosure: Condensed Cash Flow Statement (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureCondensedFinancialInformationOfParentCompanyOnlyDisclosureCondensedBalanceSheetTables</ParentRole>
      <Position>156</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R157.htm</HtmlFileName>
      <LongName>001570 - Disclosure - Supplementary Insurance Information, for Insurance Companies Disclosure: Supplementary Insurance Information For Insurance Companies Disclosure Table Text Block (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureSupplementaryInsuranceInformationForInsuranceCompaniesDisclosureSupplementaryInsuranceInformationForInsuranceCompaniesDisclosureTableTextBlockDetails</Role>
      <ShortName>Supplementary Insurance Information, for Insurance Companies Disclosure: Supplementary Insurance Information For Insurance Companies Disclosure Table Text Block (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureSupplementaryInsuranceInformationForInsuranceCompaniesDisclosureSupplementaryInsuranceInformationForInsuranceCompaniesDisclosureTableTextBlockTables</ParentRole>
      <Position>157</Position>
    </Report>
    <Report instance="ihc-20201231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R158.htm</HtmlFileName>
      <LongName>001580 - Disclosure - Supplemental Schedule of Reinsurance Premiums for Insurance Companies: Supplemental Schedule Of Reinsurance Premiums For Insurance Companies Table Text Block (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://Ihcgroup.com/20201231/role/idr_DisclosureSupplementalScheduleOfReinsurancePremiumsForInsuranceCompaniesSupplementalScheduleOfReinsurancePremiumsForInsuranceCompaniesTableTextBlockDetails</Role>
      <ShortName>Supplemental Schedule of Reinsurance Premiums for Insurance Companies: Supplemental Schedule Of Reinsurance Premiums For Insurance Companies Table Text Block (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://Ihcgroup.com/20201231/role/idr_DisclosureSupplementalScheduleOfReinsurancePremiumsForInsuranceCompaniesSupplementalScheduleOfReinsurancePremiumsForInsuranceCompaniesTableTextBlockTables</ParentRole>
      <Position>158</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="10-K" original="ihc-20201231.htm">ihc-20201231.htm</File>
    <File>ihc-20201231.xsd</File>
    <File>ihc-20201231_cal.xml</File>
    <File>ihc-20201231_def.xml</File>
    <File>ihc-20201231_lab.xml</File>
    <File>ihc-20201231_pre.xml</File>
    <File>ihc4q2020_ex21.htm</File>
    <File>ihc4q2020_ex23.htm</File>
    <File>ihc4q2020_ex31z1.htm</File>
    <File>ihc4q2020_ex31z2.htm</File>
    <File>ihc4q2020_ex32z1.htm</File>
    <File>ihc4q2020_ex32z2.htm</File>
    <File>ihc4q2020_ex4z1.htm</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy>http://fasb.org/srt/2020-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2020-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/us-gaap/2020-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
