<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2020-10-19</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000025232</issuerCik>
        <issuerName>COUSINS PROPERTIES INC</issuerName>
        <issuerTradingSymbol>CUZ</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001830534</rptOwnerCik>
            <rptOwnerName>Hicks Jane Kennedy</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3344 PEACHTREE ROAD, NE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1800</rptOwnerStreet2>
            <rptOwnerCity>ATLANTA</rptOwnerCity>
            <rptOwnerState>GA</rptOwnerState>
            <rptOwnerZipCode>30326</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>false</isDirector>
            <isOfficer>true</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle>Executive VP, Investments</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6079.00</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Includes 2,901 of restricted stock awarded under the Cousins Properties Incorporated (CPI) 2019 Omnibus Incentive Stock Plan. While the shares are being held prior to vesting, the reporting person will have the right to receive all cash dividends and to vote the restricted shares. All unvested shares will forfeit upon termination of employment.</footnote>
        <footnote id="F2">Includes 1,571 of restricted stock awarded under the Cousins Properties Incorporated (CPI) 2009 Incentive Stock Plan. While the shares are being held prior to vesting, the reporting person will have the right to receive all cash dividends and to vote the restricted shares. All unvested shares will forfeit upon termination of employment.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Jane Kennedy Hicks</signatureName>
        <signatureDate>2020-10-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
