| | | | | | | | | | | | | | | | | | | | | |
<?xml version="1.0" encoding="windows-1252"?> |
<ownershipDocument> |
| <schemaVersion> X0306 </schemaVersion> |
| <documentType> 4 </documentType> |
| <periodOfReport> 2020-03-06 </periodOfReport> |
| <issuer> |
| | <issuerCik> 0000731802 </issuerCik> |
| | <issuerName> ATMOS ENERGY CORP </issuerName> |
| | <issuerTradingSymbol> ATO </issuerTradingSymbol> |
| | </issuer> |
| <reportingOwner> |
| | <reportingOwnerId> |
| | | <rptOwnerCik> 0001181008 </rptOwnerCik> |
| | | <rptOwnerName> WARE RICHARD II </rptOwnerName> |
| | | </reportingOwnerId> |
| | <reportingOwnerAddress> |
| | | <rptOwnerStreet1> 5430 LBJ FREEWAY </rptOwnerStreet1> |
| | | <rptOwnerStreet2> 1800 III LINCOLN CENTRE </rptOwnerStreet2> |
| | | <rptOwnerCity> DALLAS </rptOwnerCity> |
| | | <rptOwnerState> TX </rptOwnerState> |
| | | <rptOwnerZipCode> 75240 </rptOwnerZipCode> |
| | | <rptOwnerStateDescription></rptOwnerStateDescription> |
| | | </reportingOwnerAddress> |
| | <reportingOwnerRelationship> |
| | | <isDirector> 1 </isDirector> |
| | | </reportingOwnerRelationship> |
| | </reportingOwner> |
| <derivativeTable> |
| | <derivativeTransaction> |
| | | <securityTitle> |
| <value> Restricted Stock Unit </value> |
| </securityTitle> |
| | | <conversionOrExercisePrice> |
| <footnoteId id="F1"/> |
| </conversionOrExercisePrice> |
| | | <transactionDate> |
| <value> 2020-03-06 </value> |
| </transactionDate> |
| | | <transactionCoding> |
| <transactionFormType> 4 </transactionFormType> |
| <transactionCode> A </transactionCode> |
| <equitySwapInvolved> 0 </equitySwapInvolved> |
| </transactionCoding> |
| | | <transactionTimeliness></transactionTimeliness> |
| | | <transactionAmounts> |
| <transactionShares> |
| <value> 1375 </value> |
| </transactionShares> |
| <transactionPricePerShare> |
| <value> 109.09 </value> |
| </transactionPricePerShare> |
| <transactionAcquiredDisposedCode> |
| <value> A </value> |
| </transactionAcquiredDisposedCode> |
| </transactionAmounts> |
| | | <exerciseDate> |
| <footnoteId id="F2"/> |
| </exerciseDate> |
| | | <expirationDate> |
| <footnoteId id="F3"/> |
| </expirationDate> |
| | | <underlyingSecurity> |
| <underlyingSecurityTitle> |
| <value> Common Stock </value> |
| </underlyingSecurityTitle> |
| <underlyingSecurityShares> |
| <value> 1375 </value> |
| </underlyingSecurityShares> |
| </underlyingSecurity> |
| | | <postTransactionAmounts> |
| <sharesOwnedFollowingTransaction> |
| <value> 1375 </value> |
| </sharesOwnedFollowingTransaction> |
| </postTransactionAmounts> |
| | | <ownershipNature> |
| <directOrIndirectOwnership> |
| <value> D </value> |
| </directOrIndirectOwnership> |
| </ownershipNature> |
| | | </derivativeTransaction> |
| | <derivativeHolding> |
| | | <securityTitle> |
| <value> Phantom Stock Units </value> |
| </securityTitle> |
| | | <conversionOrExercisePrice> |
| <footnoteId id="F4"/> |
| </conversionOrExercisePrice> |
| | | <exerciseDate> |
| <footnoteId id="F5"/> |
| </exerciseDate> |
| | | <expirationDate> |
| <footnoteId id="F6"/> |
| </expirationDate> |
| | | <underlyingSecurity> |
| <underlyingSecurityTitle> |
| <value> Common Stock </value> |
| </underlyingSecurityTitle> |
| <underlyingSecurityShares> |
| <value> 69048.1629 </value> |
| </underlyingSecurityShares> |
| </underlyingSecurity> |
| | | <postTransactionAmounts> |
| <sharesOwnedFollowingTransaction> |
| <value> 69048.1629 </value> |
| <footnoteId id="F7"/> |
| </sharesOwnedFollowingTransaction> |
| </postTransactionAmounts> |
| | | <ownershipNature> |
| <directOrIndirectOwnership> |
| <value> D </value> |
| </directOrIndirectOwnership> |
| </ownershipNature> |
| | | </derivativeHolding> |
| | </derivativeTable> |
| <footnotes> |
| | <footnote id="F1"> Each restricted stock unit represents a contingent right to receive one share of the Company's common stock. </footnote> |
| | <footnote id="F2"> The restricted stock units were granted under the 1998 Long-Term Incentive Plan (the "Plan") and will vest one year from date of grant. </footnote> |
| | <footnote id="F3"> The restricted stock units will vest and be delivered to the reporting person one year from date of grant. </footnote> |
| | <footnote id="F4"> Each unit of phantom stock is equivalent to one share of the Company's common stock. </footnote> |
| | <footnote id="F5"> The phantom stock units were granted under the Plan and are to be settled upon the reporting person's termination of service on the Company's Board. </footnote> |
| | <footnote id="F6"> The phantom stock units are to be settled upon the reporting person's termination of service on the Company's Board. </footnote> |
| | <footnote id="F7"> Includes 1,403.34 phantom stock units resulting from a dividend reinvestment feature of the Plan which were allocated to reporting person's account since March 12, 2019. </footnote> |
| | </footnotes> |
| <ownerSignature> |
| | <signatureName> /s/Suzanne Johnson by POA </signatureName> |
| | <signatureDate> 2020-03-10 </signatureDate> |
| | </ownerSignature> |
| </ownershipDocument> |