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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2014-11-17</periodOfReport>

    <issuer>
        <issuerCik>0000827187</issuerCik>
        <issuerName>SELECT COMFORT CORP</issuerName>
        <issuerTradingSymbol>SCSS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001551521</rptOwnerCik>
            <rptOwnerName>Bloomquist Andrea Lee</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>9800 59TH AVENUE NORTH</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MINNEAPOLIS</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55442</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>SVP, Chief Product Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2014-11-17</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1550</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>26.3689</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>24387</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in Column 4 is a weighted average price.  These shares were sold in multiple transactions at prices between $26.3620 and $26.4020, inclusive.  The reporting person will provide to the SEC Staff, Select Comfort or any security holder of Select Comfort, upon request, full information regarding the number of shares sold at each separate price.</footnote>
        <footnote id="F2">Includes 11,706 shares pursuant to restricted performance stock awards and 3,500 shares pursuant to a restricted stock award.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Andrea L. Bloomquist, by Rebecca L. Long, attorney-in-fact</signatureName>
        <signatureDate>2014-11-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
