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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-01-24</periodOfReport>

    <issuer>
        <issuerCik>0001105705</issuerCik>
        <issuerName>TIME WARNER INC.</issuerName>
        <issuerTradingSymbol>TWX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001237443</rptOwnerCik>
            <rptOwnerName>BEWKES JEFFREY L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE TIME WARNER CENTER</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <officerTitle>Chairman of the Board and CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Performance Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2018-01-24</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>160776</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2018-02-15</value>
            </exerciseDate>
            <expirationDate>
                <value>2018-02-15</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, Par Value $.01</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>160776</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>160776</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F3"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2018-01-24</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>332226</value>
                    <footnoteId id="F4"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F4"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, Par Value $.01</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>332226</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>332226</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each performance stock unit represents a contingent right to receive one share of common stock.</footnote>
        <footnote id="F2">On February 15, 2015, the Reporting Person was awarded 90,324 target performance stock units with a three-year performance period ending December 31, 2017.  On January 24, 2018, the Compensation and Human Development Committee approved a payout of 178% of the target PSUs under the performance standards set in 2015, based on (i) the Issuer's cumulative Adjusted EPS achieved during the performance period, which resulted in an Adjusted EPS factor of 200%, and (ii) its total stockholder return for the performance period compared to the other companies in the S&amp;P 500, which resulted in a TSR modifier of 89%. The payout factor for the performance stock units is determined by multiplying the Adjusted EPS factor and the TSR modifier.</footnote>
        <footnote id="F3">Each restricted stock unit represents a contingent right to receive one share of common stock.</footnote>
        <footnote id="F4">This award of restricted stock units was made on February 15, 2017 as a special retention award in accordance with the Agreement and Plan of Merger, dated as of October 22, 2016, among Time Warner Inc., AT&amp;T Inc. and West Merger Sub, Inc., as amended, with a value equal to approximately two times the Reporting Person's annual long-term incentive compensation, and subject to a performance condition, which the Compensation and Human Development Committee certified on January 24, 2018 had been satisfied.  Half of this award is scheduled to vest in four equal installments on each of the first four anniversaries of February 15, 2017, and the remaining half is scheduled to vest in four equal installments on each of the first four anniversaries of February 15, 2018.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: Brenda C. Karickhoff for Jeffrey L. Bewkes</signatureName>
        <signatureDate>2018-01-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
