<?xml version="1.0" encoding="utf-8"?>
<xbrl
  xmlns="http://www.xbrl.org/2003/instance"
  xmlns:dei="http://xbrl.sec.gov/dei/2020-01-31"
  xmlns:exch="http://xbrl.sec.gov/exch/2019-01-31"
  xmlns:link="http://www.xbrl.org/2003/linkbase"
  xmlns:rga="http://www.rgare.com/20200804"
  xmlns:xbrldi="http://xbrl.org/2006/xbrldi"
  xmlns:xlink="http://www.w3.org/1999/xlink">
    <link:schemaRef xlink:href="rga-20200804.xsd" xlink:type="simple"/>
    <context id="D2020Q2SD">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000898174</identifier>
        </entity>
        <period>
            <startDate>2020-08-04</startDate>
            <endDate>2020-08-04</endDate>
        </period>
    </context>
    <context id="D2020Q2SD_dei_EntityListingsExchangeAxis_exch_XNYS_dei_LegalEntityAxis_rga_RZAMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000898174</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:EntityListingsExchangeAxis">exch:XNYS</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">rga:RZAMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2020-08-04</startDate>
            <endDate>2020-08-04</endDate>
        </period>
    </context>
    <context id="D2020Q2SD_dei_EntityListingsExchangeAxis_exch_XNYS_dei_LegalEntityAxis_rga_RZBMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000898174</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:EntityListingsExchangeAxis">exch:XNYS</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">rga:RZBMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2020-08-04</startDate>
            <endDate>2020-08-04</endDate>
        </period>
    </context>
    <context id="D2020Q2SD_dei_EntityListingsExchangeAxis_exch_XNYS_dei_LegalEntityAxis_rga_RGAMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000898174</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:EntityListingsExchangeAxis">exch:XNYS</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">rga:RGAMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2020-08-04</startDate>
            <endDate>2020-08-04</endDate>
        </period>
    </context>
    <dei:AmendmentFlag
      contextRef="D2020Q2SD"
      id="Fact-C2626C01D8C13C2007C7B51D35F5885A-wk-Fact-C2626C01D8C13C2007C7B51D35F5885A">false</dei:AmendmentFlag>
    <dei:EntityCentralIndexKey
      contextRef="D2020Q2SD"
      id="Fact-2EA798E6DE1ADE296A39B51D35F54E8B-wk-Fact-2EA798E6DE1ADE296A39B51D35F54E8B">0000898174</dei:EntityCentralIndexKey>
    <dei:DocumentType
      contextRef="D2020Q2SD"
      id="d23522989e89-wk-Fact-A02E9570F363F47303A6B51D35F5A269">8-K</dei:DocumentType>
    <dei:DocumentPeriodEndDate
      contextRef="D2020Q2SD"
      id="d23522989e108-wk-Fact-BD0AA852EA3822AEB6C4B51D35F6B18A">2020-08-04</dei:DocumentPeriodEndDate>
    <dei:EntityRegistrantName
      contextRef="D2020Q2SD"
      id="d23522989e115-wk-Fact-4FFA941F18F6A6905884B51D35F34F9B">REINSURANCE GROUP OF AMERICA, INCORPORATED</dei:EntityRegistrantName>
    <dei:EntityIncorporationStateCountryCode
      contextRef="D2020Q2SD"
      id="d23522989e142-wk-Fact-9FF9086C5479E90F40E1B51D35F6835B">MO</dei:EntityIncorporationStateCountryCode>
    <dei:EntityFileNumber
      contextRef="D2020Q2SD"
      id="d23522989e152-wk-Fact-88408989A1A3C2350CC1B51D35F6661C">1-11848</dei:EntityFileNumber>
    <dei:EntityTaxIdentificationNumber
      contextRef="D2020Q2SD"
      id="d23522989e162-wk-Fact-5206B331295EFA390462B51D35F47511">43-1627032</dei:EntityTaxIdentificationNumber>
    <dei:EntityAddressAddressLine1
      contextRef="D2020Q2SD"
      id="d23522989e200-wk-Fact-DD8E3F2384AAA5B87EA5B51D35F480E6">16600 Swingley Ridge Road</dei:EntityAddressAddressLine1>
    <dei:EntityAddressCityOrTown
      contextRef="D2020Q2SD"
      id="d23522989e205-wk-Fact-4D4DEAC9DE14264BF107B51D35F62277">Chesterfield</dei:EntityAddressCityOrTown>
    <dei:EntityAddressStateOrProvince
      contextRef="D2020Q2SD"
      id="d23522989e210-wk-Fact-834C5AC6764D3BB18D8DB51D35F5E9DB">MO</dei:EntityAddressStateOrProvince>
    <dei:EntityAddressPostalZipCode
      contextRef="D2020Q2SD"
      id="d23522989e215-wk-Fact-86B8D02D561830884E71B51D35F47350">63017</dei:EntityAddressPostalZipCode>
    <dei:CityAreaCode
      contextRef="D2020Q2SD"
      id="d23522989e228-wk-Fact-85AD264F6AC3D42D1C86B51D35F47C44">636</dei:CityAreaCode>
    <dei:LocalPhoneNumber
      contextRef="D2020Q2SD"
      id="d23522989e233-wk-Fact-7FEB5103DBAA7D45F712B51D35F5D345">736-7000</dei:LocalPhoneNumber>
    <dei:WrittenCommunications
      contextRef="D2020Q2SD"
      id="d23522989e264-wk-Fact-F3AAD68E0E021B661509B51D35F6F4E9">false</dei:WrittenCommunications>
    <dei:SolicitingMaterial
      contextRef="D2020Q2SD"
      id="d23522989e275-wk-Fact-591F291062144CD513B9B51D35F526B0">false</dei:SolicitingMaterial>
    <dei:PreCommencementTenderOffer
      contextRef="D2020Q2SD"
      id="d23522989e286-wk-Fact-9521F6320C50B36BE024B51D35F71B72">false</dei:PreCommencementTenderOffer>
    <dei:PreCommencementIssuerTenderOffer
      contextRef="D2020Q2SD"
      id="d23522989e297-wk-Fact-5CB4B21A37EAF48DC20FB51D35F53BEC">false</dei:PreCommencementIssuerTenderOffer>
    <dei:Security12bTitle
      contextRef="D2020Q2SD_dei_EntityListingsExchangeAxis_exch_XNYS_dei_LegalEntityAxis_rga_RGAMember"
      id="d23522989e349-wk-Fact-A5F011A8643D97D25111B51D35F6D51B">Common Stock, par value $0.01</dei:Security12bTitle>
    <dei:TradingSymbol
      contextRef="D2020Q2SD_dei_EntityListingsExchangeAxis_exch_XNYS_dei_LegalEntityAxis_rga_RGAMember"
      id="d23522989e359-wk-Fact-17B2DEB7648DD250DF1AB51D35F44EEF">RGA</dei:TradingSymbol>
    <dei:SecurityExchangeName
      contextRef="D2020Q2SD_dei_EntityListingsExchangeAxis_exch_XNYS_dei_LegalEntityAxis_rga_RGAMember"
      id="d23522989e369-wk-Fact-DC440D7AC07E69636FDEB51D35F63313">NYSE</dei:SecurityExchangeName>
    <dei:Security12bTitle
      contextRef="D2020Q2SD_dei_EntityListingsExchangeAxis_exch_XNYS_dei_LegalEntityAxis_rga_RZAMember"
      id="d23522989e375-wk-Fact-1D0329BE79C4B74F49ACB51D35F45C70">6.20% Fixed-To-Floating Rate Subordinated Debentures due 2042</dei:Security12bTitle>
    <dei:TradingSymbol
      contextRef="D2020Q2SD_dei_EntityListingsExchangeAxis_exch_XNYS_dei_LegalEntityAxis_rga_RZAMember"
      id="d23522989e385-wk-Fact-D296E963E7B4895F8215B51D35F37AC7">RZA</dei:TradingSymbol>
    <dei:SecurityExchangeName
      contextRef="D2020Q2SD_dei_EntityListingsExchangeAxis_exch_XNYS_dei_LegalEntityAxis_rga_RZAMember"
      id="d23522989e395-wk-Fact-1A7E4C74126979DFA930B51D35F67B8E">NYSE</dei:SecurityExchangeName>
    <dei:Security12bTitle
      contextRef="D2020Q2SD_dei_EntityListingsExchangeAxis_exch_XNYS_dei_LegalEntityAxis_rga_RZBMember"
      id="d23522989e401-wk-Fact-C637C78376AE865A75E5B51D35F46672">5.75% Fixed-To-Floating Rate Subordinated Debentures due 2056</dei:Security12bTitle>
    <dei:TradingSymbol
      contextRef="D2020Q2SD_dei_EntityListingsExchangeAxis_exch_XNYS_dei_LegalEntityAxis_rga_RZBMember"
      id="d23522989e411-wk-Fact-BF12C51D2D3034297EB1B51D35F480BE">RZB</dei:TradingSymbol>
    <dei:SecurityExchangeName
      contextRef="D2020Q2SD_dei_EntityListingsExchangeAxis_exch_XNYS_dei_LegalEntityAxis_rga_RZBMember"
      id="d23522989e421-wk-Fact-6A7432FC7B4D258529B9B51D35F69D03">NYSE</dei:SecurityExchangeName>
    <dei:EntityEmergingGrowthCompany
      contextRef="D2020Q2SD"
      id="d23522989e440-wk-Fact-B38D7689E3659B310092B51D35F4B634">false</dei:EntityEmergingGrowthCompany>
</xbrl>
