ATO


Line plots across dimensions of each concept
Tables

Table of contents



us-gaap:CommonStockValue

us-gaap:CommonStockParOrStatedValuePerShare

us-gaap:CommonStockSharesIssued

us-gaap:CommonStockSharesOutstanding
us-gaap:StatementEquityComponents

us-gaap:CommonStockSharesAuthorized

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareDiluted
us-gaap:ConsolidationItems, us-gaap:MajorCustomers, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax
us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:Revenues
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:CostOfRevenue
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:ProductOrService
us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:ProductOrService

us-gaap:InterestExpense
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingIncomeLoss
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:InterestExpense
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OtherNonoperatingIncomeExpense
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:IncomeTaxExpenseBenefit
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:NetIncomeLoss
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementEquityComponents

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic

us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted

us-gaap:Assets
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:StockholdersEquity
us-gaap:StatementEquityComponents

us-gaap:AssetsCurrent

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:AccountsReceivableNetCurrent

us-gaap:OtherAssetsCurrent

us-gaap:Goodwill

us-gaap:OtherAssetsNoncurrent

us-gaap:LiabilitiesCurrent

us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent

us-gaap:OtherLiabilitiesCurrent

us-gaap:OtherLiabilitiesNoncurrent

us-gaap:StockholdersEquity
us-gaap:StatementEquityComponents

us-gaap:CommonStockValue

us-gaap:AdditionalPaidInCapitalCommonStock

us-gaap:RetainedEarningsAccumulatedDeficit

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetIncomeLoss
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementEquityComponents

us-gaap:DepreciationDepletionAndAmortization

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:ProceedsFromIssuanceOfLongTermDebt

us-gaap:PaymentsOfDividendsCommonStock
us-gaap:DebtInstrument
us-gaap:DebtInstrumentInterestRateStatedPercentage
us-gaap:StatementScenario, us-gaap:DebtInstrument

us-gaap:OperatingLeaseRightOfUseAsset

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:ProceedsFromRepaymentsOfShortTermDebt
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
ato:AlternativeRevenueProgramRevenues

ato:FinanceLeaseCost

ato:OtherComprehensiveIncomeReclassificationAdjustmentOnInterestRateAgreementsIncludedInNetIncomeNetOfTax

ato:OtherComprehensiveIncomeUnrealizedGainLossOnInterestRateAgreementsArisingDuringPeriodNetOfTax

us-gaap:AmountOfDilutiveSecuritiesStockOptionsAndRestrictiveStockUnits

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

us-gaap:CommonStockDividendsPerShareCashPaid
us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType, us-gaap:VariableRate
us-gaap:DebtInstrumentBasisSpreadOnVariableRate1
us-gaap:Range, us-gaap:CreditFacility, us-gaap:DebtInstrument, us-gaap:SubsequentEventType, us-gaap:VariableRate

us-gaap:DeferredIncomeTaxExpenseBenefit
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanInterestCost
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanServiceCost

us-gaap:DepreciationAndAmortization
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation
us-gaap:DerivativeNonmonetaryNotionalAmountVolume
us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation, us-gaap:Position

us-gaap:DividendsCommonStockCash
us-gaap:StatementEquityComponents
us-gaap:SubsidiarySaleOfStock
us-gaap:ForwardContractIndexedToIssuersEquityForwardRate

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:IncreaseDecreaseInCommodityContractAssetsAndLiabilities

us-gaap:IncreaseDecreaseInOperatingAssets

us-gaap:IncrementalCommonSharesAttributableToEquityForwardAgreements

us-gaap:InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNet

us-gaap:LeaseCost
us-gaap:ContractWithCustomerDuration, us-gaap:SupplyCommitment
us-gaap:LongTermPurchaseCommitmentMinimumVolumeRequired

us-gaap:OperatingLeaseCost

us-gaap:OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPortionAttributableToParent

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax

us-gaap:OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax
us-gaap:StatementEquityComponents

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTaxParent

us-gaap:OtherComprehensiveIncomeLossNetOfTax
us-gaap:StatementEquityComponents

us-gaap:OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent

us-gaap:OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax

us-gaap:OtherNoncashIncomeExpense

us-gaap:OtherSellingGeneralAndAdministrativeExpense
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:PaymentsForProceedsFromInvestments

us-gaap:PaymentsForProceedsFromOtherInvestingActivities

us-gaap:PaymentsOfDebtIssuanceCosts

us-gaap:PaymentsToAcquireProductiveAssets
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:ProceedsFromIssuanceOfCommonStock
us-gaap:SubsidiarySaleOfStock
us-gaap:Range
us-gaap:PublicUtilitiesApprovedEquityCapitalStructurePercentage

us-gaap:ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
us-gaap:StatementEquityComponents
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:RegulatedOperatingRevenueOther
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodSharesNewIssues
us-gaap:SubsidiarySaleOfStock
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodSharesShareBasedCompensation

us-gaap:StockIssuedDuringPeriodValueNewIssues
us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodValueShareBasedCompensation
us-gaap:StatementEquityComponents

us-gaap:TaxesOther
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic

ato:Debtandequitysecurities
us-gaap:FairValueByFairValueHierarchyLevel

ato:DerivativeAssetNetofContractNetting

ato:DerivativeLiabilityNetofContractNetting

ato:LeaseLiability
us-gaap:CreditFacility
ato:NumberofCreditFacilities
us-gaap:CreditFacility, us-gaap:SubsequentEventType

ato:RegulatoryCostOfRemovalLiabilityNoncurrent

ato:TaxCutsandJobsActof2017ChangeinTaxRateDeferredTaxLiability

us-gaap:AssetsFairValueDisclosure
us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:AvailableForSaleDebtSecuritiesAmortizedCostBasis
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FinancialInstrument
us-gaap:AvailableForSaleSecuritiesDebtSecurities
us-gaap:FinancialInstrument

us-gaap:CapitalizationLongtermDebtAndEquity
us-gaap:DebtInstrument
us-gaap:CommercialPaper

us-gaap:DebtInstrumentCarryingAmount
us-gaap:DebtInstrument
us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType
us-gaap:DebtInstrumentFaceAmount

us-gaap:DebtInstrumentUnamortizedDiscountPremiumNet

us-gaap:DeferredFinanceCostsNet

us-gaap:DeferredIncomeTaxLiabilitiesNet
us-gaap:Range, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsRemainderOfFiscalYear
us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement

us-gaap:DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset

us-gaap:DerivativeAssets

us-gaap:DerivativeCollateralRightToReclaimCash
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation
us-gaap:DerivativeFairValueOfDerivativeAsset
us-gaap:HedgingDesignation
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation
us-gaap:DerivativeFairValueOfDerivativeLiability
us-gaap:HedgingDesignation

us-gaap:DerivativeLiabilities

us-gaap:DerivativeLiabilityFairValueGrossAssetAndRightToReclaimCashOffset
us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement
us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation
us-gaap:DerivativeNonmonetaryNotionalAmountPercentOfRequiredNeedCoverage
us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation, us-gaap:SubsequentEventType
us-gaap:DerivativeNotionalAmount

us-gaap:EnergyRelatedInventoryGasStoredUnderground
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FinancialInstrument
us-gaap:EquitySecuritiesFvNi
us-gaap:FinancialInstrument

us-gaap:FinanceLeaseLiability

us-gaap:FinanceLeaseLiabilityCurrent

us-gaap:FinanceLeaseLiabilityNoncurrent

us-gaap:ForwardContractIndexedToIssuersEquitySettlementAlternativesCashAtFairValue
us-gaap:ForwardContractIndexedToIssuersEquityType
us-gaap:SubsidiarySaleOfStock

us-gaap:ForwardContractIndexedToIssuersEquitySettlementAlternativesSharesAtFairValue
us-gaap:ForwardContractIndexedToIssuersEquityType

us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity
us-gaap:CreditFacility, us-gaap:DebtInstrument, us-gaap:SubsequentEventType
us-gaap:CreditFacility, us-gaap:SubsequentEventType

us-gaap:LongTermDebtAndCapitalLeaseObligations

us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent

us-gaap:LongTermDebtAndCapitalLeaseObligationsIncludingCurrentMaturities

us-gaap:LongTermDebtFairValue

us-gaap:OperatingLeaseLiability

us-gaap:OperatingLeaseLiabilityCurrent

us-gaap:OperatingLeaseLiabilityNoncurrent

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentNet
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentPlantInService

us-gaap:RegulatoryAssets
us-gaap:RegulatoryAsset

us-gaap:RegulatoryLiabilities
us-gaap:BalanceSheetLocation, us-gaap:RegulatoryLiability
us-gaap:RegulatoryLiability

us-gaap:ShortTermBorrowings

Tables

  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
us-gaap:CommonStockValue ██████▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▆▆▆▆▆▆▆▆▆▆▆▆▁▁612000.0611000.0597000.0591000.0585000.0584000.0556000.0556000.0555000.0555000.0531000.0530000.0526000.0526000.0520000.0519000.0511000.0510000.0507000.0507000.0505000.0504000.0502000.0502000.0501000.0455000.0453000.0453000.0453000.0453000.0451000.0451000.0450000.0448000.0451000.0451000.0452000.0453.0451.0NA
us-gaap:CommonStockParOrStatedValuePerShare ▄▄▄▄▄▄▄▄0.0050.0050.0050.0050.0050.0050.0050.005NANA0.005NANANANANANANANA0.0050.0050.0050.00.0050.0050.0050.00.0050.0050.00.00.00.00.00.00.00.00.00.0NA
us-gaap:CommonStockSharesIssued ██▇▇▇▇▆▆▆▅▄▄▄▄▄▄▄▄▃▃▃▃▃▃▃▁▁▁▁▁▁▁▁▁▁▁▁▁▁1221221191181161161111111111101061061051051031031021021011011001001001001009090909090909090909090909090NA
us-gaap:CommonStockSharesOutstanding ██▇▇▇▇▆▆▆▅▄▄▄▄▄▄▄▄▃▃▃▃▃▃▃▁▁1221221191181161161111111111101061061051051031031021021011011001001001001009090NANANANANANANANANANANANANA
 us-gaap:CommonStockSharesOutstanding us-gaap:StatementEquityComponents us-gaap:CommonStock██▇▆▅▅▃▃▃▃▁122122119118116116111111111110106NANANA103NANANA101NANANA100NANANA90NANANA90NANANA90NANANA90NA
us-gaap:CommonStockSharesAuthorized ▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄200200200200200200200200200200200200200200200200200200200200200200200200200200200200200200200200200200200200200200200NA
us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding █▁122121NA118117113NA111111108NANANANANANANANANA102101101NA1019691NA919191NA909090NA90900NA92
us-gaap:WeightedAverageNumberOfSharesOutstandingBasic █▁122121NA118117113NA111111108NANANANANANANANANA102101101NA1009590NA909090NA909090NA90900NA92
us-gaap:EarningsPerShareBasic ▅▄▁▂▅▄▁▂▄█1.951.470.490.681.831.380.350.641.62.89NANANANA0.330.691.381.00.230.551.350.960.230.451.40.960.080.431.280.890.090.341.20.750.02-0.011.450.810.02-0.03
us-gaap:EarningsPerShareDiluted ▅▄▁▂▅▄▁▂▄█1.951.470.490.681.821.380.350.641.62.89NANANANA0.330.691.381.00.230.551.350.960.230.451.380.950.080.421.270.880.090.341.20.750.02-0.011.450.810.02-0.03
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems,us-gaap:MajorCustomers,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,ato:CommercialCustomers,ato:Gassalesrevenue,ato:DistributionSegment█▁230211NANA278218NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems,us-gaap:MajorCustomers,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,ato:IndustrialCustomers,ato:Gassalesrevenue,ato:DistributionSegment█▁2524NANA3534NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems,us-gaap:MajorCustomers,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,ato:PublicAuthorityandOtherCustomers,ato:Gassalesrevenue,ato:DistributionSegment█▁1413NANA1713NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems,us-gaap:MajorCustomers,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,ato:ResidentialCustomers,ato:Gassalesrevenue,ato:DistributionSegment█▁596552NANA695547NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,ato:Gassalesrevenue,ato:DistributionSegment█▁867801NANA1027814NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,ato:Miscellaneousrevenue,ato:DistributionSegment▄▄66NANA76NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,ato:Miscellaneousrevenue,ato:PipelineandStorageSegment▁█15NANA21NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,ato:Transportationrevenue,ato:DistributionSegment█▁2826NANA2725NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,ato:Transportationrevenue,ato:PipelineandStorageSegment█▁154152NANA142147NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,ato:DistributionSegment█▁902834NANA1062847NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,ato:PipelineandStorageSegment▁█156157NANA145149NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:Revenues ▃▃▁▁▄▃▁▂▅▃▁▁▄▃▂▂▄▃▂▂▆▅▃▃█▅▂▃▅▄▂▂▅▄▃▃▆▄▃▂9778754434851094877444562121988946452698878067863211329066566861540125877894219641255685857130810345525851243110177984315811133778761
 us-gaap:Revenues us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:IntersegmentElimination,ato:PipelineandStorageSegment█▁100-100NANA9894NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:Revenues us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,ato:DistributionSegment▆▅▁▁▇▅▁▂█▅▁▂93382840344410578384075351199860437494NANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:Revenues us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,ato:PipelineandStorageSegment▇███▅▅▄▃▂▃▁▁146148147149135134132127120126117117NANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:Revenues us-gaap:StatementBusinessSegments ato:DistributionSegment█▁932827NANA1057838NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:CostOfRevenue █▁317296NA31471342NA130NANANANANANANANANANANANANANANANANANANANANANANANANANANANA11520NANA
 us-gaap:CostOfRevenue us-gaap:ConsolidationItems,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,us-gaap:NaturalGasUsRegulated,ato:DistributionSegment418NA120139570437138230727463NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:CostOfRevenue us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,ato:DistributionSegment█▁418397NANA570437NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:CostOfRevenue us-gaap:ProductOrService us-gaap:NaturalGasUsRegulated317NA13314713424313062636672114427311NANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:InterestExpense ▂▅▆▁▄▅▄▃▅▇█▆▄▇▆▅▅▆▇▅▅▆█▇▇█2227281926272423273133282631302727303127272933313132NA3233303434363538353703837
 us-gaap:InterestExpense us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,ato:DistributionSegment▁▄▄▁▄▅▃▃▄▇█▅101615101518141316212318NANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:InterestExpense us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,ato:PipelineandStorageSegment▅▄█▁▅▂▄▄▄▄▄▄1110138119101010101010NANANANANANANANANANANANANANANANANANANANANANANANANANANANA
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  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
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 us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents us-gaap:RetainedEarnings█▁239178NA80214157NA71178314NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:DepreciationDepletionAndAmortization ██▇▆▆▆▅▅▅▄▄▃▂▂▂▁▁▁105105100979696929089888480777776737171NANANANANANANANANANANANANANANANANANANANANANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
us-gaap:NetCashProvidedByUsedInInvestingActivities ▂▁▂▃▄▃▄▃▅▄▅▆█▃▅▆▆▅▅▆▇▆▅▇▇▇-463002000.0-528235000.0-488259000.0-426980000.0-353128000.0-415293000.0-376342000.0-399080000.0-306772000.0-381372000.0-308951000.0-230685000.0-124533000.0-392137000.0-285351000.0-258036000.0-245700000.0-290645000.0-306153000.0-225612000.0-180938000.0-262052000.0-284356000.0-189307000.0-177479000.0-186434000.0NANA-201517000.0-191300000.0-107639000.0-186620000.0-159527000.0-155474000.0-233730000.0-145458000.0-248074468.0-123532.0-179915000.0-129212000.0
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
us-gaap:NetCashProvidedByUsedInFinancingActivities ▅█▆▅▃▇▆▄▂▆▅▄▁▆▅▅▃▆▅▄▁▆▅▄▁▆132520306116-15245527965-25523614461-30927296107-170270172-3-360316165-35-337280NANA-204221769-25412418428-16900-32
us-gaap:ProceedsFromIssuanceOfLongTermDebt ▁█▁▁▅▆▁▁▁▁▁█▁▂▁▁▁▁▁▁▁▅▁▁▁▁07990044859600000759012500000004930000NANANANA00NANA0NANANA0NA
us-gaap:PaymentsOfDividendsCommonStock ██▇▆▆▆▅▅▅▄▄▄▄▄▃▃▃▃▃▂▂▂▂▂▂▁7069636161585454545148474747444343434338383937373733NANA32313131313130306203031
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
 us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:DebtInstrument ato:UnsecuredSeniorNotesDue2044██████████████████████▁0.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.0NANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:StatementScenario,us-gaap:DebtInstrument srt:ScenarioForecast,ato:UnsecuredSeniorNotesInFiscal2021NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:StatementScenario,us-gaap:DebtInstrument srt:ScenarioForecast,ato:UnsecuredSeniorNotesInFiscal2022NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA

Common Stock Value

us-gaap:CommonStockValue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value612000.0611000.0597000.0591000.0585000.0584000.0556000.0556000.0555000.0555000.0531000.0530000.0526000.0526000.0520000.0519000.0511000.0510000.0507000.0507000.0505000.0504000.0502000.0502000.0501000.0455000.0453000.0453000.0453000.0453000.0451000.0451000.0450000.0448000.0451000.0451000.0452000.0453.0451.0
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Common Stock Par Or Stated Value Per Share

us-gaap:CommonStockParOrStatedValuePerShare



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value0.0050.0050.0050.0050.0050.0050.0050.0050.0050.0050.0050.0050.00.0050.0050.0050.00.0050.0050.00.00.00.00.00.00.00.00.00.0
Percentage of CommonStockParOrStatedValuePerShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.00.0100.0100.00.00.00.00.00.00.00.00.00.00.0

Common Stock Shares Issued

us-gaap:CommonStockSharesIssued



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value1221221191181161161111111111101061061051051031031021021011011001001001001009090909090909090909090909090
Percentage of CommonStockSharesIssued100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Common Stock Shares Outstanding

us-gaap:CommonStockSharesOutstanding



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value1221221191181161161111111111101061061051051031031021021011011001001001001009090
Percentage of CommonStockSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:CommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-09-302015-09-302014-09-302013-09-302012-09-302011-09-302010-09-302009-09-302008-09-30
Value122122119118116116111111111110106103101100909090909290
Percentage of CommonStockSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.0

Common Stock Shares Authorized

us-gaap:CommonStockSharesAuthorized



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-11-302017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value2002002002002002002002002002004200200200200200200200200200200200200200200200200200200200200200200200200200200200200200
Percentage of CommonStockSharesAuthorized100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Diluted Shares Outstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-312015-06-302015-03-312014-12-312014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-06-302012-03-312011-12-312011-06-302011-03-312010-12-312010-06-302010-03-312009-12-31
Value12212111811711311111110810210110110196919191919090909090092920
Percentage of WeightedAverageNumberOfDilutedSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Shares Outstanding Basic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-312015-06-302015-03-312014-12-312014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-06-302012-03-312011-12-312011-06-302011-03-312010-12-312010-06-302010-03-312009-12-31
Value12212111811711311111110810210110110095909090909090909090092920
Percentage of WeightedAverageNumberOfSharesOutstandingBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Basic

us-gaap:EarningsPerShareBasic



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value1.951.470.490.681.831.380.350.641.62.890.330.691.381.00.230.551.350.960.230.451.40.960.080.431.280.890.090.341.20.750.02-0.011.450.810.02-0.031.221.0
Percentage of EarningsPerShareBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Diluted

us-gaap:EarningsPerShareDiluted



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value1.951.470.490.681.821.380.350.641.62.890.330.691.381.00.230.551.350.960.230.451.380.950.080.421.270.880.090.341.20.750.02-0.011.450.810.02-0.031.221.0
Percentage of EarningsPerShareDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Income Loss From Continuing Operations Per Basic Share

Income Loss From Continuing Operations Per Diluted Share

Revenue From Contract With Customer Excluding Assessed Tax

us-gaap:ConsolidationItems, us-gaap:MajorCustomers, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax

us-gaap:OperatingSegments, ato:CommercialCustomers, ato:Gassalesrevenue, ato:DistributionSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value230211278218
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0
Percentage of Revenues23.624.125.524.9
Percentage of Revenues us-gaap:OperatingSegments ato:CommercialCustomers ato:Gassalesrevenue ato:DistributionSegment0.00.00.00.0

us-gaap:OperatingSegments, ato:IndustrialCustomers, ato:Gassalesrevenue, ato:DistributionSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value25243534
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax11.111.812.915.8
Percentage of Revenues2.62.83.33.9
Percentage of Revenues us-gaap:OperatingSegments ato:IndustrialCustomers ato:Gassalesrevenue ato:DistributionSegment0.00.00.00.0

us-gaap:OperatingSegments, ato:PublicAuthorityandOtherCustomers, ato:Gassalesrevenue, ato:DistributionSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value14131713
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.46.26.16.1
Percentage of Revenues1.51.51.61.5
Percentage of Revenues us-gaap:OperatingSegments ato:PublicAuthorityandOtherCustomers ato:Gassalesrevenue ato:DistributionSegment0.00.00.00.0

us-gaap:OperatingSegments, ato:ResidentialCustomers, ato:Gassalesrevenue, ato:DistributionSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value596552695547
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax258.4261.3249.4250.3
Percentage of Revenues61.063.163.662.4
Percentage of Revenues us-gaap:OperatingSegments ato:ResidentialCustomers ato:Gassalesrevenue ato:DistributionSegment0.00.00.00.0

us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ato:Gassalesrevenue, ato:DistributionSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value8678011027814
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax375.9379.2368.4372.1
Percentage of Revenues88.791.593.992.8
Percentage of Revenues us-gaap:OperatingSegments ato:Gassalesrevenue ato:DistributionSegment0.00.00.00.0

us-gaap:OperatingSegments, ato:Miscellaneousrevenue, ato:DistributionSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value6676
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.03.22.63.2
Percentage of Revenues0.70.80.70.8
Percentage of Revenues us-gaap:OperatingSegments ato:Miscellaneousrevenue ato:DistributionSegment0.00.00.00.0

us-gaap:OperatingSegments, ato:Miscellaneousrevenue, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value1521
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.62.41.00.8
Percentage of Revenues0.10.60.30.2
Percentage of Revenues us-gaap:OperatingSegments ato:Miscellaneousrevenue ato:PipelineandStorageSegment0.00.00.00.0

us-gaap:OperatingSegments, ato:Transportationrevenue, ato:DistributionSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value28262725
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax12.412.69.911.6
Percentage of Revenues2.93.02.52.9
Percentage of Revenues us-gaap:OperatingSegments ato:Transportationrevenue ato:DistributionSegment0.00.00.00.0

us-gaap:OperatingSegments, ato:Transportationrevenue, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value154152142147
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax67.171.951.067.3
Percentage of Revenues15.817.413.016.8
Percentage of Revenues us-gaap:OperatingSegments ato:Transportationrevenue ato:PipelineandStorageSegment0.00.00.00.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ato:DistributionSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value9028341062847
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax391.2395.0381.0386.9
Percentage of Revenues92.495.397.196.5
Percentage of Revenues us-gaap:OperatingSegments ato:DistributionSegment96.8100.8100.5101.0

us-gaap:OperatingSegments, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value156157145149
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax67.674.452.068.1
Percentage of Revenues16.018.013.317.0
Percentage of Revenues us-gaap:OperatingSegments ato:PipelineandStorageSegment106.7106.1106.9110.9

Revenue From Contract With Customer Including Assessed Tax

Revenues

us-gaap:Revenues



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value9778754434851094877444562121988946452698878067863211329066566861540125877894219641255685857130810345525851243110177984315811133778761
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidationItems

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value-101-101-107-108-98-95-95-100-100-98-90-84
Percentage of Revenues-10.4-11.5-24.3-22.3-9.0-10.9-21.5-17.9-8.3-11.0-19.5-16.1
Percentage of Revenues-10.4-11.5-24.3-22.3-9.0-10.9-21.5-17.9-8.3-11.0-19.5-16.1
Percentage of Revenues us-gaap:IntersegmentElimination100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:IntersegmentElimination, ato:DistributionSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value0000
Percentage of Revenues0.1-0.10.10.1
Percentage of Revenues0.1-0.10.10.1
Percentage of Revenues us-gaap:IntersegmentElimination ato:DistributionSegment100.0100.0100.0100.0

us-gaap:IntersegmentElimination, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value100-1009894
Percentage of Revenues10.3-11.59.010.8
Percentage of Revenues10.3-11.59.010.8
Percentage of Revenues us-gaap:IntersegmentElimination ato:PipelineandStorageSegment100.0100.0100.0100.0

us-gaap:OperatingSegments, ato:DistributionSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value93382840344410578384075351199860437494
Percentage of Revenues95.494.691.091.696.695.691.695.298.496.894.293.8
Percentage of Revenues95.494.691.091.696.695.691.695.298.496.894.293.8
Percentage of Revenues us-gaap:OperatingSegments ato:DistributionSegment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value146148147149135134132127120126117117
Percentage of Revenues15.016.933.330.712.415.329.822.79.914.225.322.3
Percentage of Revenues15.016.933.330.712.415.329.822.79.914.225.322.3
Percentage of Revenues us-gaap:OperatingSegments ato:PipelineandStorageSegment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementBusinessSegments

ato:DistributionSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value9328271057838
Percentage of Revenues95.494.596.695.5
Percentage of Revenues95.494.596.695.5
Percentage of Revenues ato:DistributionSegment100.0100.0100.0100.0

ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value45473739
Percentage of Revenues4.65.53.44.5
Percentage of Revenues4.65.53.44.5
Percentage of Revenues ato:PipelineandStorageSegment100.0100.0100.0100.0

Cost Of Revenue

us-gaap:CostOfRevenue



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302011-03-312010-12-312010-03-312009-12-31
Value317296314713421301152014850
Percentage of CostOfRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues32.533.96.443.139.023.372.90.10.00.0

us-gaap:ConsolidationItems

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-03-312018-12-31
Value-101-100-98-95
Percentage of CostOfRevenue-31.9-34.0-20.9-27.8
Percentage of Revenues-10.4-11.5-9.0-10.8
Percentage of Revenues us-gaap:IntersegmentElimination99.799.799.799.7

us-gaap:ConsolidationItems, us-gaap:ProductOrService

us-gaap:IntersegmentElimination, us-gaap:NaturalGasUsRegulated



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-101-107-108-98-95-95-100-100-97
Percentage of CostOfRevenue-31.90.0-345.1-20.9-27.80.0-76.80.00.0
Percentage of Revenues-10.4-24.2-22.3-9.0-10.8-21.4-17.9-8.2-11.0
Percentage of Revenues us-gaap:IntersegmentElimination us-gaap:NaturalGasUsRegulated0.00.00.00.00.00.00.00.00.0

us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, us-gaap:NaturalGasUsRegulated, ato:DistributionSegment



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value418120139570437138230727463
Percentage of CostOfRevenue131.80.0445.4120.9127.90.0176.40.00.0
Percentage of Revenues42.927.328.752.149.931.141.159.652.2
Percentage of Revenues us-gaap:OperatingSegments us-gaap:NaturalGasUsRegulated ato:DistributionSegment0.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, us-gaap:NaturalGasUsRegulated, ato:PipelineandStorageSegment



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value000000000
Percentage of CostOfRevenue0.10.0-0.3-0.0-0.10.00.40.00.0
Percentage of Revenues0.00.0-0.0-0.0-0.00.00.10.00.1
Percentage of Revenues us-gaap:OperatingSegments us-gaap:NaturalGasUsRegulated ato:PipelineandStorageSegment0.00.00.00.00.00.00.00.00.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ato:DistributionSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value418397570437
Percentage of CostOfRevenue131.8133.9120.9127.9
Percentage of Revenues42.945.452.149.9
Percentage of Revenues us-gaap:OperatingSegments ato:DistributionSegment44.948.053.952.2

us-gaap:OperatingSegments, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value0000
Percentage of CostOfRevenue0.10.0-0.0-0.1
Percentage of Revenues0.00.0-0.0-0.0
Percentage of Revenues us-gaap:OperatingSegments ato:PipelineandStorageSegment0.10.1-0.1-0.3

us-gaap:ProductOrService

us-gaap:NaturalGasUsRegulated



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value31713314713424313062636672114427311
Percentage of CostOfRevenue100.00.0100.0100.0100.00.0100.00.00.00.00.00.00.0
Percentage of Revenues32.53.16.443.139.09.723.351.441.315.621.743.339.9
Percentage of Revenues us-gaap:NaturalGasUsRegulated0.00.00.00.00.00.00.00.00.00.00.00.00.0

Cost Of Goods Sold

Interest Expense

us-gaap:InterestExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value22272819262724232731332826313027273031272729333131323233303434363538353703837390
Percentage of InterestExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues2.33.16.54.02.53.25.54.22.23.57.35.42.74.04.54.42.43.44.74.11.82.44.33.41.62.63.82.53.06.26.02.93.24.94.22.40.05.04.90.00.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ato:DistributionSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value101615101518141316212318
Percentage of InterestExpense48.760.153.354.159.065.458.357.061.967.869.364.5
Percentage of Revenues1.11.93.52.21.52.13.22.41.42.45.03.5
Percentage of Revenues us-gaap:OperatingSegments ato:DistributionSegment1.22.03.82.41.52.23.52.51.42.55.33.7

us-gaap:OperatingSegments, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value1110138119101010101010
Percentage of InterestExpense51.339.946.745.941.034.641.743.038.132.230.735.5
Percentage of Revenues1.21.23.01.91.01.12.31.80.91.12.21.9
Percentage of Revenues us-gaap:OperatingSegments ato:PipelineandStorageSegment7.87.39.16.08.17.27.77.98.68.08.88.6

Gross Profit

Operating Expenses

Operating Income Loss

us-gaap:OperatingIncomeLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value331252891222972368912226824191140285209841372501967511725018783106250170508621015422842081444134217038322240
Percentage of OperatingIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues33.928.920.225.227.226.920.121.922.127.219.726.728.926.912.521.722.121.711.517.116.214.910.811.312.713.67.410.116.115.04.114.516.813.15.34.013.80.04.94.20.00.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ato:DistributionSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value253180234822816936612111734677
Percentage of OperatingIncomeLoss76.571.326.439.876.971.740.750.278.771.751.154.8
Percentage of Revenues25.920.65.310.020.919.38.211.017.419.510.114.6
Percentage of Revenues us-gaap:OperatingSegments ato:DistributionSegment27.221.85.910.921.620.28.911.517.720.110.715.6

us-gaap:OperatingSegments, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value777266736867536159684463
Percentage of OperatingIncomeLoss23.528.773.660.223.128.359.349.822.028.548.945.2
Percentage of Revenues8.08.314.915.16.37.612.010.94.87.79.712.1
Percentage of Revenues us-gaap:OperatingSegments ato:PipelineandStorageSegment53.348.944.749.350.749.840.148.048.854.438.154.2

Interest Expense

us-gaap:InterestExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value22272819262724232731332826313027273031272729333131323233303434363538353703837390
Percentage of InterestExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues2.33.16.54.02.53.25.54.22.23.57.35.42.74.04.54.42.43.44.74.11.82.44.33.41.62.63.82.53.06.26.02.93.24.94.22.40.05.04.90.00.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ato:DistributionSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value101615101518141316212318
Percentage of InterestExpense48.760.153.354.159.065.458.357.061.967.869.364.5
Percentage of Revenues1.11.93.52.21.52.13.22.41.42.45.03.5
Percentage of Revenues us-gaap:OperatingSegments ato:DistributionSegment1.22.03.82.41.52.23.52.51.42.55.33.7

us-gaap:OperatingSegments, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value1110138119101010101010
Percentage of InterestExpense51.339.946.745.941.034.641.743.038.132.230.735.5
Percentage of Revenues1.21.23.01.91.01.12.31.80.91.12.21.9
Percentage of Revenues us-gaap:OperatingSegments ato:PipelineandStorageSegment7.87.39.16.08.17.27.77.98.68.08.88.6

Other Nonoperating Income Expense

us-gaap:OtherNonoperatingIncomeExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value-24914-7-1-20-2-2000000-1-10-1-1-10-1-2010-11-10-1-2-12600000
Percentage of OtherNonoperatingIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-0.30.62.10.30.4-0.9-0.2-0.4-0.0-0.2-0.6-0.10.1-0.1-0.10.1-0.1-0.1-0.30.1-0.1-0.1-0.2-0.0-0.1-0.2-0.10.10.1-2.1-0.30.0-0.2-0.3-0.21.7-0.00.1-0.10.00.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ato:DistributionSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value-51435-60-1-1-1-20
Percentage of OtherNonoperatingIncomeExpense173.740.048.1182.7124.483.9-33.159.5601.294.472.021.5
Percentage of Revenues-0.50.21.00.60.5-0.70.1-0.2-0.1-0.2-0.4-0.0
Percentage of Revenues us-gaap:OperatingSegments ato:DistributionSegment-0.60.21.10.70.5-0.80.1-0.2-0.1-0.2-0.5-0.0

us-gaap:OperatingSegments, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value224-1-1-1-100000
Percentage of OtherNonoperatingIncomeExpense-73.760.051.9-82.7-24.416.1133.140.5255.331.228.078.5
Percentage of Revenues0.20.31.1-0.3-0.1-0.1-0.3-0.1-0.1-0.1-0.2-0.0
Percentage of Revenues us-gaap:OperatingSegments ato:PipelineandStorageSegment1.52.03.2-0.9-0.8-0.9-1.1-0.6-0.5-0.5-0.7-0.2

Income Loss From Continuing Operations

Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest

Income Tax Expense Benefit

us-gaap:IncomeTaxExpenseBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value665111236043252662-10619419763193979611934835825288349196647-271766410-17400-1700
Percentage of IncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues6.85.92.74.95.54.95.74.75.1-11.94.27.89.88.22.96.27.16.83.05.05.44.73.23.04.33.92.35.14.6-4.93.05.33.8-0.1-0.24.70.00.0-0.20.00.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ato:DistributionSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value503628463091148-99622
Percentage of IncomeTaxExpenseBenefit75.869.825.236.576.870.236.445.177.193.431.853.8
Percentage of Revenues5.24.10.71.84.23.52.12.13.9-11.11.34.2
Percentage of Revenues us-gaap:OperatingSegments ato:DistributionSegment5.44.40.72.04.43.62.32.24.0-11.51.44.5

us-gaap:OperatingSegments, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value16158151312161414-71318
Percentage of IncomeTaxExpenseBenefit24.230.274.863.523.229.863.654.922.96.668.246.2
Percentage of Revenues1.71.82.03.11.31.53.62.61.2-0.82.83.6
Percentage of Revenues us-gaap:OperatingSegments ato:PipelineandStorageSegment11.010.66.010.110.39.612.111.411.8-5.511.216.2

Income Taxes Paid Net

Profit Loss

Comprehensive Income Net Of Tax

us-gaap:ComprehensiveIncomeNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-06-302012-03-312011-12-312011-06-302011-03-312010-12-312010-06-30
Value240179598121213554792003133553170220245087109-231221031502010711165148911612151-81261163
Percentage of ComprehensiveIncomeNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues24.620.513.416.819.415.412.214.216.435.27.610.117.328.33.67.97.712.1-3.617.86.71.30.02.15.58.97.711.48.92.99.84.7-1.08.010.30.5

Net Income Loss

us-gaap:NetIncomeLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value239178588021415738711783143570164125347114110223561379723451338773811680731109681013201-31140
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues24.520.413.216.619.618.08.712.714.735.37.713.416.716.05.011.212.511.43.68.28.97.83.04.86.86.91.14.58.97.81.45.38.86.20.3-0.18.40.00.2-0.40.00.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ato:DistributionSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value18712993217211413351452491536
Percentage of NetIncomeLoss78.172.616.840.380.172.634.349.681.179.342.851.6
Percentage of Revenues19.114.82.26.715.713.03.06.311.928.03.36.9
Percentage of Revenues us-gaap:OperatingSegments ato:DistributionSegment20.015.72.47.316.313.63.36.612.128.93.57.4

us-gaap:OperatingSegments, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value524848484243253533652034
Percentage of NetIncomeLoss21.927.483.259.719.927.465.750.418.920.757.248.4
Percentage of Revenues5.45.610.99.93.94.95.76.42.87.34.46.5
Percentage of Revenues us-gaap:OperatingSegments ato:PipelineandStorageSegment36.033.032.932.231.532.219.228.127.951.417.429.2

us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-31
Value2391788021415771178314
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues24.520.416.619.618.012.714.735.3
Percentage of Revenues us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.0

Net Income Loss Available To Common Stockholders Basic

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value239178802141577117831334711411022356137972345133863311277-930104651-1126700-4
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues24.520.416.619.617.912.714.735.35.011.212.511.33.68.28.97.73.04.86.86.93.98.67.5-1.75.18.45.90.1-0.28.06.20.0-0.5

Net Income Loss Available To Common Stockholders Diluted

us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value239178588021415738711783132356137972345133863311277-930104651-1126700-4
Percentage of NetIncomeLossAvailableToCommonStockholdersDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues24.520.413.216.619.617.98.712.714.735.33.68.28.97.73.04.86.86.93.98.67.5-1.75.18.45.90.1-0.28.06.20.0-0.5

Assets

us-gaap:Assets



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value147161438813367128811267412615118741150711356112641074910498103611057910010972795439554909288848926911585948357848786167940780279537964749573497368763572826993699576
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidationItems

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302018-06-302017-09-30
Value-2633-2600-2491-2199-1922
Percentage of Assets-17.9-18.1-18.6-19.1-17.9
Percentage of Assets-17.9-18.1-18.6-19.1-17.9
Percentage of Assets us-gaap:IntersegmentElimination100.0100.0100.0100.0100.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ato:DistributionSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-09-30
Value139461359912579120831190411836111091084010050
Percentage of Assets94.894.594.193.893.993.893.694.293.5
Percentage of Assets94.894.594.193.893.993.893.694.293.5
Percentage of Assets us-gaap:OperatingSegments ato:DistributionSegment100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-09-30
Value340333893279317430713040296328662621
Percentage of Assets23.123.624.524.624.224.125.024.924.4
Percentage of Assets23.123.624.524.624.224.125.024.924.4
Percentage of Assets us-gaap:OperatingSegments ato:PipelineandStorageSegment100.0100.0100.0100.0100.0100.0100.0100.0100.0

Liabilities And Stockholders Equity

us-gaap:LiabilitiesAndStockholdersEquity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value147161438813367128811267412615118741150711356112641074910498103611057910010972795439554909288848926911585948357848786167940780279537964749573497368763572826993699576
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Stockholders Equity

us-gaap:StockholdersEquity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302009-09-30
Value6304612757505641550853484769475947214563389839013834369834633466334432723194323831393063308631163124266125802581254324242359235423602267225523352373222176
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets42.842.643.043.843.542.440.241.441.640.536.337.237.035.034.635.635.034.235.136.435.233.635.937.336.830.932.533.132.030.431.532.032.029.731.033.433.931.532.20.0

us-gaap:StatementEquityComponents

us-gaap:AccumulatedGainLossNetCashFlowHedgeParent



Period End2020-03-312019-12-312019-09-302019-03-312018-12-312018-09-30
Value-112-113-114-116-114-91
Percentage of StockholdersEquity-1.8-1.9-2.0-2.1-2.1-1.9
Percentage of Assets-0.8-0.8-0.9-0.9-0.9-0.8
Percentage of Assets us-gaap:AccumulatedGainLossNetCashFlowHedgeParent0.00.00.00.00.00.0

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-09-30
Value000000866676534334477675
Percentage of StockholdersEquity-0.00.00.00.00.0-0.00.20.10.10.20.20.20.10.10.10.10.10.10.20.20.20.20.20.2
Percentage of Assets-0.00.00.00.00.0-0.00.10.10.10.10.10.10.10.00.00.00.00.00.10.10.10.10.10.1
Percentage of Assets us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedOtherComprehensiveIncome



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-09-302012-09-302011-09-302010-09-302009-09-302008-09-30
Value-112-113-114-115-116-114-83-76-85-106-105-104-86-92-188-178-157-102-109-62-128-94-1238-47-48-23-20-35
Percentage of StockholdersEquity-1.8-1.9-2.0-2.1-2.1-2.1-1.8-1.6-1.8-2.3-2.7-2.7-2.3-2.5-5.4-5.1-4.7-3.1-3.4-1.9-4.1-3.1-0.41.5-2.0-2.1-1072.9-0.90.0
Percentage of Assets-0.8-0.8-0.9-0.9-0.9-0.9-0.7-0.7-0.7-0.9-1.0-1.0-0.8-0.9-1.9-1.8-1.6-1.1-1.2-0.7-1.4-1.0-0.10.5-0.6-0.7-345.50.00.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-09-302015-09-302014-09-302013-09-302012-09-302011-09-302010-09-302009-09-302008-09-30
Value39863979371235993485347629742964295129402536238822302180176517451732171417911744
Percentage of StockholdersEquity63.264.964.663.863.365.062.462.362.564.465.169.069.870.668.474.076.878700.282.30.0
Percentage of Assets27.127.727.827.927.527.625.125.826.026.123.623.924.525.422.223.323.825346.20.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-09-302015-09-302014-09-302013-09-302012-09-302011-09-302010-09-302009-09-302008-09-30
Value00000000000000000000
Percentage of StockholdersEquity0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.020.70.00.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.06.70.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-09-302015-09-302014-09-302013-09-302012-09-302011-09-302010-09-302009-09-302008-09-30
Value2430226121522157213819851878187118541729146712621073917775660570486405343
Percentage of StockholdersEquity38.536.937.438.238.837.139.439.339.337.937.636.533.629.730.028.025.322352.018.60.0
Percentage of Assets16.515.716.116.716.915.715.816.316.315.413.612.611.810.79.88.87.87198.70.00.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Assets Current

us-gaap:AssetsCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value829812458503671912478452622778539534563979681648652863630616817111877577410591299683682100211648277758931261101098998410
Percentage of AssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets5.65.63.43.95.37.24.03.95.56.95.05.15.49.36.86.76.89.06.96.99.212.39.09.312.515.18.68.712.614.611.010.612.116.513.914.214.117.512.9

Cash And Cash Equivalents At Carrying Value

us-gaap:CashAndCashEquivalentsAtCarryingValue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302008-09-30
Value3201892446108218132071542669454447664778284395123425113619466316512464274785131117153001802310046
Percentage of CashAndCashEquivalentsAtCarryingValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.21.30.20.40.91.70.10.20.60.50.20.70.40.40.50.70.50.80.30.51.11.40.50.61.62.30.80.40.81.60.90.40.61.11.81.72.21.82.00.00.00.00.00.0

Accounts Receivable Net Current

us-gaap:AccountsReceivableNetCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value37743523028541947825325340748922225033645830027736145629530151160734338867166130135048550023421635048927334245800
Percentage of AccountsReceivableNetCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.63.01.72.23.33.82.12.23.64.32.12.43.24.33.02.93.84.83.23.45.76.74.04.77.97.73.84.56.16.33.12.94.86.43.84.96.67.84.0

Other Assets Current

us-gaap:OtherAssetsCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value63717265656946525570106626176100605291705867109111126126157709025326527229127536031627314300
Percentage of OtherAssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.40.50.50.50.50.60.40.50.50.61.00.60.60.71.00.60.51.00.80.70.81.21.31.51.51.80.91.23.23.33.64.03.74.74.33.92.13.22.2

Property Plant And Equipment Gross

Accumulated Depreciation Depletion And Amortization Property Plant And Equipment

Property Plant And Equipment Net

Goodwill

us-gaap:Goodwill



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-09-302010-09-30
Value730730730730730730730730730730730729729729743742742742742742742742742741741741741740740740740740739
Percentage of Goodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets5.05.15.55.75.85.86.26.36.46.56.87.07.06.97.47.67.87.88.28.48.38.18.68.98.78.69.39.59.39.39.910.210930.5

Finite Lived Intangible Assets Net

Deferred Tax Assets Liabilities Net

Other Assets Noncurrent

us-gaap:OtherAssetsNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value60759439130630127429425224223622031033031730528230829528831334034135037941742248453850046345139240038738334735700
Percentage of OtherAssetsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets4.14.12.92.42.42.22.52.22.12.12.13.03.23.03.02.93.23.13.23.53.83.74.14.54.94.96.16.96.35.86.05.35.45.15.35.05.15.05.3

Liabilities Current

us-gaap:LiabilitiesCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value93384512099018641455191514651349959101374514961949178815291227151511549161018142091011551363201397872092616451275111011081179867648107711
Percentage of LiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets6.35.99.07.06.811.516.112.711.98.59.47.114.418.417.915.712.915.912.710.311.415.610.613.816.123.412.39.211.720.717.015.115.015.511.99.315.420.217.2

Long Term Debt Current

Accounts Payable And Accrued Liabilities Current

us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value19030826520624430121719823028523316418526825919822628023822729539731131244245824122931636721517830943229131242300
Percentage of AccountsPayableAndAccruedLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.32.12.01.61.92.41.81.72.02.52.21.61.82.52.62.02.42.92.62.63.34.43.63.75.25.33.02.94.04.62.92.44.25.74.04.56.17.13.9

Taxes Payable Current

Other Liabilities Current

us-gaap:OtherLiabilitiesCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value54353747949449557854757353833633232239038144941037347145743749747240234342036536834837744648946837435736733330100
Percentage of OtherLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.73.73.63.83.94.64.65.04.73.03.13.13.83.64.54.23.94.95.04.95.65.24.74.15.04.24.64.54.75.66.56.45.14.75.04.84.34.86.1

Long Term Debt Noncurrent

Deferred Tax Liabilities Noncurrent

Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent

Other Liabilities Noncurrent

us-gaap:OtherLiabilitiesNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value5845881211751701721587410018117516915515824522823715516194181129684840394342394450746046756256443942700
Percentage of OtherLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets4.04.10.91.41.31.41.30.60.91.61.61.61.51.52.52.42.51.61.81.12.01.40.80.60.50.50.60.50.50.66.86.36.37.47.86.36.16.06.4

Stockholders Equity

us-gaap:StockholdersEquity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302009-09-30
Value6304612757505641550853484769475947214563389839013834369834633466334432723194323831393063308631163124266125802581254324242359235423602267225523352373222176
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets42.842.643.043.843.542.440.241.441.640.536.337.237.035.034.635.635.034.235.136.435.233.635.937.336.830.932.533.132.030.431.532.032.029.731.033.433.931.532.20.0

us-gaap:StatementEquityComponents

us-gaap:AccumulatedGainLossNetCashFlowHedgeParent



Period End2020-03-312019-12-312019-09-302019-03-312018-12-312018-09-30
Value-112-113-114-116-114-91
Percentage of StockholdersEquity-1.8-1.9-2.0-2.1-2.1-1.9
Percentage of Assets-0.8-0.8-0.9-0.9-0.9-0.8
Percentage of Assets us-gaap:AccumulatedGainLossNetCashFlowHedgeParent0.00.00.00.00.00.0

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-09-30
Value000000866676534334477675
Percentage of StockholdersEquity-0.00.00.00.00.0-0.00.20.10.10.20.20.20.10.10.10.10.10.10.20.20.20.20.20.2
Percentage of Assets-0.00.00.00.00.0-0.00.10.10.10.10.10.10.10.00.00.00.00.00.10.10.10.10.10.1
Percentage of Assets us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedOtherComprehensiveIncome



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-09-302012-09-302011-09-302010-09-302009-09-302008-09-30
Value-112-113-114-115-116-114-83-76-85-106-105-104-86-92-188-178-157-102-109-62-128-94-1238-47-48-23-20-35
Percentage of StockholdersEquity-1.8-1.9-2.0-2.1-2.1-2.1-1.8-1.6-1.8-2.3-2.7-2.7-2.3-2.5-5.4-5.1-4.7-3.1-3.4-1.9-4.1-3.1-0.41.5-2.0-2.1-1072.9-0.90.0
Percentage of Assets-0.8-0.8-0.9-0.9-0.9-0.9-0.7-0.7-0.7-0.9-1.0-1.0-0.8-0.9-1.9-1.8-1.6-1.1-1.2-0.7-1.4-1.0-0.10.5-0.6-0.7-345.50.00.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-09-302015-09-302014-09-302013-09-302012-09-302011-09-302010-09-302009-09-302008-09-30
Value39863979371235993485347629742964295129402536238822302180176517451732171417911744
Percentage of StockholdersEquity63.264.964.663.863.365.062.462.362.564.465.169.069.870.668.474.076.878700.282.30.0
Percentage of Assets27.127.727.827.927.527.625.125.826.026.123.623.924.525.422.223.323.825346.20.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-09-302015-09-302014-09-302013-09-302012-09-302011-09-302010-09-302009-09-302008-09-30
Value00000000000000000000
Percentage of StockholdersEquity0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.020.70.00.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.06.70.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-09-302015-09-302014-09-302013-09-302012-09-302011-09-302010-09-302009-09-302008-09-30
Value2430226121522157213819851878187118541729146712621073917775660570486405343
Percentage of StockholdersEquity38.536.937.438.238.837.139.439.339.337.937.636.533.629.730.028.025.322352.018.60.0
Percentage of Assets16.515.716.116.716.915.715.816.316.315.413.612.611.810.79.88.87.87198.70.00.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Common Stock Value

us-gaap:CommonStockValue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value612000.0611000.0597000.0591000.0585000.0584000.0556000.0556000.0555000.0555000.0531000.0530000.0526000.0526000.0520000.0519000.0511000.0510000.0507000.0507000.0505000.0504000.0502000.0502000.0501000.0455000.0453000.0453000.0453000.0453000.0451000.0451000.0450000.0448000.0451000.0451000.0452000.0453.0451.0
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Additional Paid In Capital Common Stock

us-gaap:AdditionalPaidInCapitalCommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value398639793712359934853476297429642951294025362525246424512388237122552242223022072192218121802172216317691765175717531750174517371728172517321730172811
Percentage of AdditionalPaidInCapitalCommonStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets27.127.727.827.927.527.625.125.826.026.123.624.123.823.223.924.423.623.524.524.824.623.925.426.025.520.522.222.522.022.023.323.623.522.623.824.724.723.925.3

Retained Earnings Accumulated Deficit

us-gaap:RetainedEarningsAccumulatedDeficit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value24302261215221572138198518781871185417291467148014561339126212731245113210731092107597591793292482877580079370966068468560757059963100
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets16.515.716.116.716.915.715.816.316.315.413.614.114.112.712.613.113.011.911.812.312.010.710.711.210.99.69.810.310.08.98.89.39.38.07.88.69.07.37.2

Accumulated Other Comprehensive Income Loss Net Of Tax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-112-113-114-115-116-114-83-76-85-106-105-104-86-92-188-178-157-102-109-62-128-94-121136633823-3-36-47-67-53-65-4851400
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-0.8-0.8-0.9-0.9-0.9-0.9-0.7-0.7-0.7-0.9-1.0-1.0-0.8-0.9-1.9-1.8-1.6-1.1-1.2-0.7-1.4-1.0-0.10.10.40.70.50.3-0.0-0.5-0.6-0.9-0.7-0.9-0.70.10.20.3-0.3

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value461172159248396164892835781731211934351161701683857011817651327109139456343462968158376-15638143801311114830
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues47.219.736.051.136.218.820.150.547.419.526.136.844.015.025.126.734.07.818.125.733.32.214.114.823.22.726.52.912.327.030.2-1.48.19.627.70.016.914.60.00.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value-463002000.0-528235000.0-488259000.0-426980000.0-353128000.0-415293000.0-376342000.0-399080000.0-306772000.0-381372000.0-308951000.0-230685000.0-124533000.0-392137000.0-285351000.0-258036000.0-245700000.0-290645000.0-306153000.0-225612000.0-180938000.0-262052000.0-284356000.0-189307000.0-177479000.0-186434000.0-201517000.0-191300000.0-107639000.0-186620000.0-159527000.0-155474000.0-233730000.0-145458000.0-248074468.0-123532.0-179915000.0-129212000.0-233457688.0-117312.0
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-47.4-60.3-110.0-87.9-32.3-47.3-84.6-71.0-25.2-42.9-66.5-43.8-12.6-50.3-42.1-40.8-21.7-32.1-46.6-32.9-11.7-20.8-36.5-20.1-9.0-14.9-15.4-18.5-19.5-31.9-12.8-14.1-30.0-17.2-15.7-0.0-23.1-17.00.00.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value132520306116-15245527965-25523614461-30927296107-170270172-3-360316165-35-337280-204221769-25412418428-16900-32-1300
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues13.659.469.124.0-14.051.862.911.6-20.926.631.011.7-31.334.914.217.0-15.129.826.3-0.5-23.425.121.2-3.7-17.222.3-15.621.413.81.6-20.511.323.73.4-10.70.0-0.1-4.30.00.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value461172159248396164892835781731211934351161701683857011817651327109139456343462968158376-15638143801311114830
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues47.219.736.051.136.218.820.150.547.419.526.136.844.015.025.126.734.07.818.125.733.32.214.114.823.22.726.52.912.327.030.2-1.48.19.627.70.016.914.60.00.0

Net Income Loss

us-gaap:NetIncomeLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value239178588021415738711783143570164125347114110223561379723451338773811680731109681013201-31140
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues24.520.413.216.619.618.08.712.714.735.37.713.416.716.05.011.212.511.43.68.28.97.83.04.86.86.91.14.58.97.81.45.38.86.20.3-0.18.40.00.2-0.40.00.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ato:DistributionSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value18712993217211413351452491536
Percentage of NetIncomeLoss78.172.616.840.380.172.634.349.681.179.342.851.6
Percentage of Revenues19.114.82.26.715.713.03.06.311.928.03.36.9
Percentage of Revenues us-gaap:OperatingSegments ato:DistributionSegment20.015.72.47.316.313.63.36.612.128.93.57.4

us-gaap:OperatingSegments, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value524848484243253533652034
Percentage of NetIncomeLoss21.927.483.259.719.927.465.750.418.920.757.248.4
Percentage of Revenues5.45.610.99.93.94.95.76.42.87.34.46.5
Percentage of Revenues us-gaap:OperatingSegments ato:PipelineandStorageSegment36.033.032.932.231.532.219.228.127.951.417.429.2

us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-31
Value2391788021415771178314
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues24.520.416.619.618.012.714.735.3
Percentage of Revenues us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.0

Profit Loss

Depreciation Depletion And Amortization

us-gaap:DepreciationDepletionAndAmortization



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value105105100979696929089888480777776737171
Percentage of DepreciationDepletionAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Increase Decrease In Inventories

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value-463002000.0-528235000.0-488259000.0-426980000.0-353128000.0-415293000.0-376342000.0-399080000.0-306772000.0-381372000.0-308951000.0-230685000.0-124533000.0-392137000.0-285351000.0-258036000.0-245700000.0-290645000.0-306153000.0-225612000.0-180938000.0-262052000.0-284356000.0-189307000.0-177479000.0-186434000.0-201517000.0-191300000.0-107639000.0-186620000.0-159527000.0-155474000.0-233730000.0-145458000.0-248074468.0-123532.0-179915000.0-129212000.0-233457688.0-117312.0
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-47.4-60.3-110.0-87.9-32.3-47.3-84.6-71.0-25.2-42.9-66.5-43.8-12.6-50.3-42.1-40.8-21.7-32.1-46.6-32.9-11.7-20.8-36.5-20.1-9.0-14.9-15.4-18.5-19.5-31.9-12.8-14.1-30.0-17.2-15.7-0.0-23.1-17.00.00.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value132520306116-15245527965-25523614461-30927296107-170270172-3-360316165-35-337280-204221769-25412418428-16900-32-1300
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues13.659.469.124.0-14.051.862.911.6-20.926.631.011.7-31.334.914.217.0-15.129.826.3-0.5-23.425.121.2-3.7-17.222.3-15.621.413.81.6-20.511.323.73.4-10.70.0-0.1-4.30.00.0

Proceeds From Issuance Of Long Term Debt

us-gaap:ProceedsFromIssuanceOfLongTermDebt



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312012-09-302012-06-302011-09-302010-09-30
Value079900448596000007590125000000049300000000
Percentage of ProceedsFromIssuanceOfLongTermDebt0.0100.00.00.0100.0100.00.00.00.00.00.0100.00.0100.00.00.00.00.00.00.00.0100.00.00.00.00.00.00.0100.00.0

Repayments Of Long Term Debt

Payments Of Dividends Common Stock

us-gaap:PaymentsOfDividendsCommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value706963616158545454514847474744434343433838393737373332313131313130306203031620
Percentage of PaymentsOfDividendsCommonStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Payments For Repurchase Of Common Stock

Repayments Of Long Term Debt

Debt Instrument Interest Rate Stated Percentage

us-gaap:DebtInstrument

us-gaap:DebtInstrumentInterestRateStatedPercentage

ato:UnsecuredSeniorNotesDue2044



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-10-152014-09-30
Value0.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.041250.0
Percentage of DebtInstrumentInterestRateStatedPercentage100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations ato:UnsecuredSeniorNotesDue20440.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StatementScenario, us-gaap:DebtInstrument

srt:ScenarioForecast, ato:UnsecuredSeniorNotesInFiscal2021



Period End2021-09-30
Value0.0069
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations srt:ScenarioForecast ato:UnsecuredSeniorNotesInFiscal20210.0

srt:ScenarioForecast, ato:UnsecuredSeniorNotesInFiscal2022



Period End2021-09-30
Value0.0133
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations srt:ScenarioForecast ato:UnsecuredSeniorNotesInFiscal20220.0

Effective Income Tax Rate Continuing Operations

Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period

Share Based Compensation

Deferred Tax Liabilities

Deferred Tax Assets Net

Unrecognized Tax Benefits

Deferred Tax Assets Valuation Allowance

Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions

Operating Lease Right Of Use Asset

us-gaap:OperatingLeaseRightOfUseAsset



Period End2020-03-312019-12-31
Value222223
Percentage of OperatingLeaseRightOfUseAsset100.0100.0

Cash And Cash Equivalents Period Increase Decrease

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents



Period End2020-03-312019-12-312019-09-302019-03-312018-12-312018-09-30
Value3201892410821813
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0

Proceeds From Repayments Of Short Term Debt

us-gaap:ProceedsFromRepaymentsOfShortTermDebt



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value199-464389740-575331115-207-110189-412-27011015943-13630520526-3283502002-689320-59925636042-222173215-3-12801300-760
Percentage of ProceedsFromRepaymentsOfShortTermDebt100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

ato:AlternativeRevenueProgramRevenues

us-gaap:OperatingSegments, ato:DistributionSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value29-6-5-8
Percentage of AlternativeRevenueProgramRevenues100.0100.0100.0100.0

us-gaap:OperatingSegments, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value-9-8-9-14
Percentage of AlternativeRevenueProgramRevenues-33.2133.2174.0167.5

ato:FinanceLeaseCost



Period End2020-03-31
Value105000.0
Percentage of FinanceLeaseCost100.0

ato:OtherComprehensiveIncomeReclassificationAdjustmentOnInterestRateAgreementsIncludedInNetIncomeNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value1111000000000000000000
Percentage of OtherComprehensiveIncomeReclassificationAdjustmentOnInterestRateAgreementsIncludedInNetIncomeNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ato:OtherComprehensiveIncomeUnrealizedGainLossOnInterestRateAgreementsArisingDuringPeriodNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value0000-3-2214721-1-2-18491-10-39-534-4054-32-52
Percentage of OtherComprehensiveIncomeUnrealizedGainLossOnInterestRateAgreementsArisingDuringPeriodNetOfTax0.00.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AmountOfDilutiveSecuritiesStockOptionsAndRestrictiveStockUnits



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value0.00.00.00.00.00.00.00.00.00.00.00.00.00.0-4000.00.02000.01000.00.02000.02000.0-1000.00.03000.01000.00.00.03000.02000.01000.00.0
Percentage of AmountOfDilutiveSecuritiesStockOptionsAndRestrictiveStockUnits0.00.00.00.00.00.00.00.00.00.00.00.00.00.0100.00.0100.0100.00.0100.0100.0100.00.0100.0100.00.00.0100.0100.0100.00.0

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect



Period End2020-03-312019-12-312019-03-312018-12-31
Value130164-109204
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect100.0100.0100.0100.0

us-gaap:CommonStockDividendsPerShareCashPaid



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value0.5750.5750.52500000000000010.5250.5250.5250.48499999999999990.4850.4850.4850.449999999999999960.450.450.450.419999999999999930.420.420.420.39000000000000010.390.390.390.36999999999999990.370.370.370.350.350.350.3450.3450.3450.3450.34000000000000010.340.340.340.33500000000000020.3350.3350.335
Percentage of CommonStockDividendsPerShareCashPaid100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType, us-gaap:VariableRate

us-gaap:DebtInstrumentBasisSpreadOnVariableRate1

ato:A200MillionTermLoanAgreement, us-gaap:SecuredDebt, us-gaap:SubsequentEvent, us-gaap:LondonInterbankOfferedRateLIBOR



Period End2020-04-09
Value0.0125
Percentage of DebtInstrumentBasisSpreadOnVariableRate1100.0

us-gaap:Range, us-gaap:CreditFacility, us-gaap:DebtInstrument, us-gaap:SubsequentEventType, us-gaap:VariableRate

srt:Maximum, us-gaap:RevolvingCreditFacility, ato:A600MillionRevolvingCreditFacility, us-gaap:SubsequentEvent, us-gaap:LondonInterbankOfferedRateLIBOR



Period End2020-04-23
Value0.0125
Percentage of DebtInstrumentBasisSpreadOnVariableRate10.0

srt:Minimum, us-gaap:RevolvingCreditFacility, ato:A600MillionRevolvingCreditFacility, us-gaap:SubsequentEvent, us-gaap:LondonInterbankOfferedRateLIBOR



Period End2020-04-23
Value0.0
Percentage of DebtInstrumentBasisSpreadOnVariableRate10.0

us-gaap:DeferredIncomeTaxExpenseBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value63461123564018236253383981672238735928337555393072476045-1618624010115010142440
Percentage of DeferredIncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value00222211110000
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value-310-1-1-10-3-3-30-4-4-4
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses-970.7380.530.3-78.5-78.6-78.66.8-188.5-190.5-190.90.3-601.7-601.0-601.0

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value43000.043000.043000.043000.044000.043000.03000.02000.03000.03000.0-411000.0-411000.0-411000.0-411000.0
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value-58000.0-58000.0-59000.0-57000.0-58000.0-58000.0-58000.0-57000.0-58000.0-58000.0-58000.0-57000.0-58000.0-58000.0
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit-134.9-134.9-137.2-132.6-131.8-134.9-1933.3-2850.0-1933.3-1933.314.113.914.114.1

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value22222222221111
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value77777766666666
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets269.7269.7266.9267.0266.9266.9345.6345.5345.6345.5389.4389.4389.2389.4

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanInterestCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value22222222222222
Percentage of DefinedBenefitPlanInterestCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value55166616661666
Percentage of DefinedBenefitPlanInterestCost220.2220.256.5229.7229.9229.654.7236.5235.9235.858.2235.9235.8235.8

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value33000022222222
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value62-2555-5897-3888
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost212.767.3-295.1530.0530.3530.2-261.0385.6447.8333.5-106.1304.0304.2304.0

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanServiceCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value33222233333333
Percentage of DefinedBenefitPlanServiceCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value44344434442555
Percentage of DefinedBenefitPlanServiceCost138.2138.2117.5149.7149.6149.7110.5158.7151.5151.079.1167.8167.8167.8

us-gaap:DepreciationAndAmortization



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value10510510097969692908988848077767673717170686867686361605857595859605959565705551530
Percentage of DepreciationAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ato:DistributionSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value767673706969676665656362
Percentage of DepreciationAndAmortization72.072.472.872.372.272.672.773.373.474.075.378.4

us-gaap:OperatingSegments, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value292827272626252423222017
Percentage of DepreciationAndAmortization28.027.627.227.727.827.427.326.726.626.024.721.6

us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation

us-gaap:DerivativeNonmonetaryNotionalAmountVolume

ato:GasPurchases, us-gaap:CommodityContract, us-gaap:Nondesignated



Period End2020-03-312019-12-31
Value-19880.119900.0
Percentage of DerivativeNonmonetaryNotionalAmountVolume100.0100.0

us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation, us-gaap:Position

ato:GasPurchases, us-gaap:CommodityContract, us-gaap:Nondesignated, us-gaap:Long



Period End2020-03-312019-12-31
Value-14525.4914530.0
Percentage of DerivativeNonmonetaryNotionalAmountVolume73.173.0

us-gaap:DividendsCommonStockCash



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-31
Value7069616158545451
Percentage of DividendsCommonStockCash100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-31
Value7069616158545451
Percentage of DividendsCommonStockCash100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:SubsidiarySaleOfStock

us-gaap:ForwardContractIndexedToIssuersEquityForwardRate

ato:ForwardSalesEquityAgreements



Period End2020-03-312019-12-31
Value3.6199999999999903106.51
Percentage of ForwardContractIndexedToIssuersEquityForwardRate100.0100.0

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value30623070104274200649724120855111259177531102211644390221156487421613653178125-36471721070-320600-51850
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ato:DistributionSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value237165124121814422471931492158
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments77.672.018.239.479.472.135.148.480.172.138.952.4

us-gaap:OperatingSegments, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value686457635656415048583353
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments22.428.081.860.620.627.964.951.619.927.961.147.6

us-gaap:IncreaseDecreaseInCommodityContractAssetsAndLiabilities



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-312017-06-302017-03-312016-12-312016-06-302016-03-312015-12-312015-06-302015-03-312014-12-312014-06-302014-03-312013-12-312013-03-312012-12-312012-06-302012-03-312011-12-31
Value2-41-2201-21-22-317-177-15820-2-6530-1528-7-8
Percentage of IncreaseDecreaseInCommodityContractAssetsAndLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInOperatingAssets



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-312017-06-302017-03-312016-12-312016-06-302016-03-312015-12-312015-06-302015-03-312014-12-312014-06-302014-03-312013-12-312013-03-312012-12-312012-06-302012-03-312011-12-312011-06-302011-03-312010-12-312010-06-302010-03-312009-12-31
Value-46161-43-26133-92-2461290-951506-751605-23417714-177160-107144-37-113180-48090-1110
Percentage of IncreaseDecreaseInOperatingAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncrementalCommonSharesAttributableToEquityForwardAgreements



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value81000.0246000.073000.0355000.0175000.032000.00.00.00.00.0
Percentage of IncrementalCommonSharesAttributableToEquityForwardAgreements100.0100.0100.0100.0100.0100.00.00.00.00.0

us-gaap:InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNet



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-06-30
Value-1-11-1000000000000000000-1-1-1-1-1000
Percentage of InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LeaseCost



Period End2020-03-31
Value10
Percentage of LeaseCost100.0

us-gaap:ContractWithCustomerDuration, us-gaap:SupplyCommitment

us-gaap:LongTermPurchaseCommitmentMinimumVolumeRequired

us-gaap:ShortTermContractWithCustomer, us-gaap:SupplyCommitment



Period End2020-03-312019-12-31
Value-25655.925700.0
Percentage of LongTermPurchaseCommitmentMinimumVolumeRequired100.0100.0

us-gaap:OperatingLeaseCost



Period End2020-03-31
Value10
Percentage of OperatingLeaseCost100.0

us-gaap:OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPortionAttributableToParent



Period End2020-03-312019-12-312019-03-312018-12-31
Value11-2-22
Percentage of OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPortionAttributableToParent100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-06-302012-03-31
Value000000000010101000-200-1000200002
Percentage of OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax



Period End2020-03-312019-12-312019-03-312018-12-312015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-03-312012-12-31
Value00-3-2256-41-81-24-23-2221308
Percentage of OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:AccumulatedGainLossNetCashFlowHedgeParent



Period End2020-03-312019-12-312019-03-312018-12-31
Value00-3-22
Percentage of OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax-0.0-0.0103.1100.0

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-03-312012-12-31
Value000000100010101000-200-1000210
Percentage of OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax100.0100.00.00.0-3.1-0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.2-2.31.30.8-3.60.110.95.0-4.6

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent



Period End2020-03-312019-03-31
Value1-2
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent100.0100.0

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTaxParent



Period End2020-03-312019-03-31
Value312000.0-825000.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTaxParent100.0100.0

us-gaap:OtherComprehensiveIncomeLossNetOfTax



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-03-312012-12-31
Value011-2-22821-1-4765-33-81-23-25-26243211
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:AccumulatedGainLossNetCashFlowHedgeParent



Period End2020-03-312019-12-312019-03-312018-12-31
Value11-2-22
Percentage of OtherComprehensiveIncomeLossNetOfTax118.3100.1103.6100.0

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-03-312012-12-31
Value000000000010101000-200-1000200
Percentage of OtherComprehensiveIncomeLossNetOfTax-18.3-0.10.08.2-3.6-0.00.03.6-4.410.10.00.00.00.00.00.00.00.05.1-0.3-2.81.31.3-1.51.09.9-0.6-3.2

us-gaap:AccumulatedOtherComprehensiveIncome



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value0111-2-2215821-10-17595-9-20-546-4765-33-81
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.00.0100.0100.0100.00.0100.0100.0100.00.00.00.00.00.00.00.00.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-06-302012-03-312011-12-31
Value0111-2-2215821-10-17595-9-20-546-4765-33-81-23-25-2624273211-1412-16
Percentage of OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value000000000000000000-100000010000010-100010
Percentage of OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax100.00.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherNoncashIncomeExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value-708-40-612-5-5-614-4-5-418-9-5-418-7-5-422-10-5-5-83-211254-145
Percentage of OtherNoncashIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherSellingGeneralAndAdministrativeExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value14715217716414913816314516112916012813212416413713312415713213311813912512411512111110611910711011610711211601121111170
Percentage of OtherSellingGeneralAndAdministrativeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidationItems

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value000000000000
Percentage of OtherSellingGeneralAndAdministrativeExpense-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.20.00.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ato:DistributionSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value11511413212311710511811113010311799
Percentage of OtherSellingGeneralAndAdministrativeExpense78.475.174.775.478.776.372.177.180.879.772.777.4

us-gaap:OperatingSegments, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value323845403233453329264329
Percentage of OtherSellingGeneralAndAdministrativeExpense21.825.125.424.821.523.928.023.118.220.227.322.6

us-gaap:PaymentsForProceedsFromInvestments



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-312017-06-302017-03-312016-12-312016-06-302016-03-312015-12-31
Value014-106105-110-202
Percentage of PaymentsForProceedsFromInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsForProceedsFromOtherInvestingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value-2-2-40-2-2-2-2-2-2-2-2-1-1-400-1-10001-40521002111100000
Percentage of PaymentsForProceedsFromOtherInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsOfDebtIssuanceCosts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value07004600000
Percentage of PaymentsOfDebtIssuanceCosts0.0100.00.0100.0100.0100.00.00.00.00.0100.0

us-gaap:PaymentsToAcquireProductiveAssets



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value46552949442136141637939431038332425226129729025724629130722518026128219317818019319919023518615615423214312301801292320
Percentage of PaymentsToAcquireProductiveAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ato:DistributionSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value373404361316293302276284224241213205
Percentage of PaymentsToAcquireProductiveAssets80.276.473.275.181.272.772.872.072.263.065.781.4

us-gaap:OperatingSegments, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value92124132104671131031108614111146
Percentage of PaymentsToAcquireProductiveAssets19.823.626.824.918.827.327.228.027.837.034.318.6

us-gaap:ProceedsFromIssuanceOfCommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-11-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302014-09-302014-06-302014-02-182014-02-182013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value025910099049400039539504904909800000039039000100000700080
Percentage of ProceedsFromIssuanceOfCommonStock100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.00.0100.00.0100.0100.0100.00.00.00.00.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:SubsidiarySaleOfStock

ato:AtTheMarket



Period End2020-03-312019-12-31
Value-1214
Percentage of ProceedsFromIssuanceOfCommonStock104.482.9

ato:ForwardSalesEquityAgreements



Period End2020-03-312019-12-31
Value044
Percentage of ProceedsFromIssuanceOfCommonStock-0.017.1

us-gaap:Range

us-gaap:PublicUtilitiesApprovedEquityCapitalStructurePercentage

srt:Maximum



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value0.00.60.00.00.00.6
Percentage of PublicUtilitiesApprovedEquityCapitalStructurePercentage0.0100.00.00.00.0100.0

srt:Minimum



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value0.00.50.00.00.00.5
Percentage of PublicUtilitiesApprovedEquityCapitalStructurePercentage0.083.30.00.00.083.3

us-gaap:ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax



Period End2020-03-312019-12-312019-03-312018-12-312015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-03-312012-12-31
Value-1-100-9-80023-2-2-3
Percentage of ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:AccumulatedGainLossNetCashFlowHedgeParent



Period End2020-03-312019-12-312019-03-312018-12-31
Value-1-100
Percentage of ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax100.1100.0100.0100.0

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-03-312012-12-31
Value0000000000000000000000000010
Percentage of ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax-0.1-0.00.00.0-0.0-0.00.00.00.00.00.00.00.00.00.00.00.00.00.0-3.3-0.0-5.9-12.419.75.8-0.0-84.6-0.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:RegulatedOperatingRevenueOther

us-gaap:OperatingSegments, ato:DistributionSegment



Period End2020-03-312019-12-312019-03-312018-12-31
Value0000
Percentage of RegulatedOperatingRevenueOther100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodSharesNewIssues

us-gaap:CommonStock



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-31
Value02105004
Percentage of StockIssuedDuringPeriodSharesNewIssues100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:SubsidiarySaleOfStock

ato:AtTheMarket



Period End2020-03-312019-12-312018-12-31
Value020
Percentage of StockIssuedDuringPeriodSharesNewIssues0.081.00.0

ato:ForwardSalesEquityAgreements



Period End2020-03-312019-12-312019-03-312018-11-302018-12-31
Value00022
Percentage of StockIssuedDuringPeriodSharesNewIssues0.017.6-1635.849.10.0

us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodSharesShareBasedCompensation

us-gaap:CommonStock



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-31
Value7660.0164549.085966.028938.0184464.089813.021440.0235960.0
Percentage of StockIssuedDuringPeriodSharesShareBasedCompensation100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodValueNewIssues



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-31
Value3263103549836400
Percentage of StockIssuedDuringPeriodValueNewIssues100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-31
Value3263103549836400
Percentage of StockIssuedDuringPeriodValueNewIssues100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CommonStock



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-31
Value00000000
Percentage of StockIssuedDuringPeriodValueNewIssues0.00.00.00.00.00.00.00.0

us-gaap:StockIssuedDuringPeriodValueShareBasedCompensation



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-31
Value341032852
Percentage of StockIssuedDuringPeriodValueShareBasedCompensation100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-31
Value341032852
Percentage of StockIssuedDuringPeriodValueShareBasedCompensation100.0100.0100.0100.0100.0100.0100.099.9

us-gaap:CommonStock



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-31
Value00000000
Percentage of StockIssuedDuringPeriodValueShareBasedCompensation0.00.00.00.00.00.00.00.1

us-gaap:TaxesOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value74686169796455727362546265575059625150636949466360425054413646544332525403551590
Percentage of TaxesOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ato:DistributionSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value686052627156476464554656
Percentage of TaxesOther91.787.885.788.889.887.185.388.788.687.885.690.3

us-gaap:OperatingSegments, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value688788888776
Percentage of TaxesOther8.312.214.311.210.212.914.711.311.412.214.49.7

us-gaap:UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic



Period End2020-03-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value178000.0136000.064000.0170000.0135000.059000.0161000.0328000.051000.075000.0193000.0153000.050000.0108000.0231000.0172000.030000.0111000.0296000.0216000.044000.0106000.0334000.0232000.0
Percentage of UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ato:Debtandequitysecurities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value96104101102969299
Percentage of Debtandequitysecurities100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:FairValueInputsLevel1



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value61706769645864
Percentage of Debtandequitysecurities64.367.866.168.266.663.764.5

us-gaap:FairValueInputsLevel2



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value34333432323335
Percentage of Debtandequitysecurities35.732.233.931.833.436.335.5

ato:DerivativeAssetNetofContractNetting



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value0112131000333114
Percentage of DerivativeAssetNetofContractNetting100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ato:DerivativeLiabilityNetofContractNetting



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value1853087567686117112109117132284
Percentage of DerivativeLiabilityNetofContractNetting100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ato:LeaseLiability



Period End2020-03-312019-12-31
Value237233
Percentage of LeaseLiability100.0100.0

us-gaap:CreditFacility

ato:NumberofCreditFacilities

us-gaap:RevolvingCreditFacility



Period End2020-03-31
Value3.0
Percentage of NumberofCreditFacilities100.0

us-gaap:CreditFacility, us-gaap:SubsequentEventType

us-gaap:RevolvingCreditFacility, us-gaap:SubsequentEvent



Period End2020-04-23
Value4.0
Percentage of NumberofCreditFacilities0.0

ato:RegulatoryCostOfRemovalLiabilityNoncurrent



Period End2020-03-312019-12-312019-09-302019-03-312018-12-312018-09-302017-09-30
Value448451473462468466485
Percentage of RegulatoryCostOfRemovalLiabilityNoncurrent100.0100.0100.0100.0100.0100.0100.0

ato:TaxCutsandJobsActof2017ChangeinTaxRateDeferredTaxLiability



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-09-30
Value6946997057097127177397330
Percentage of TaxCutsandJobsActof2017ChangeinTaxRateDeferredTaxLiability100.0100.0100.0100.0100.0100.0100.0100.00.0

us-gaap:AssetsFairValueDisclosure



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-09-30
Value961051031049895101989491919285173136178147147127157133147178190205297244247203182158119
Percentage of AssetsFairValueDisclosure100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:FairValueInputsLevel1



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-09-30
Value6170676964586464565957554812591136101958411082948484671208511612012710812816399
Percentage of AssetsFairValueDisclosure63.766.965.066.565.561.463.566.059.564.962.759.656.572.566.776.569.264.666.270.062.264.147.244.533.140.435.047.259.370.168.10.00.083.1

us-gaap:FairValueInputsLevel2



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-09-30
Value353436353336363338323437371417889110118125140191264140167215270258250214211213232276115
Percentage of AssetsFairValueDisclosure36.333.135.033.534.538.636.534.040.535.137.340.443.581.757.149.874.980.398.489.1144.2178.578.688.0104.790.6105.7100.9105.4115.9134.40.00.096.3

us-gaap:AvailableForSaleDebtSecuritiesAmortizedCostBasis



Period End2020-03-312019-12-312019-09-30
Value323131
Percentage of AvailableForSaleDebtSecuritiesAmortizedCostBasis100.0100.0100.0

us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FinancialInstrument

us-gaap:AvailableForSaleSecuritiesDebtSecurities

us-gaap:FairValueInputsLevel2, us-gaap:DebtSecurities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value32323131293031
Percentage of AvailableForSaleSecuritiesDebtSecurities100.0100.0100.0100.0100.0100.0100.0

us-gaap:FinancialInstrument

us-gaap:DebtSecurities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value32323131293031
Percentage of AvailableForSaleSecuritiesDebtSecurities100.0100.0100.0100.0100.0100.0100.0

us-gaap:CapitalizationLongtermDebtAndEquity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value10633104529279917190368432726373777339763169656968614960135651567258005727565056935594551955425072508046175036503749984380431543114316447344614541418143
Percentage of CapitalizationLongtermDebtAndEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DebtInstrument

us-gaap:CommercialPaper

ato:FiveYearUnsecuredRevolvingCreditAgreement



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-09-30
Value1994647400575244447
Percentage of CommercialPaper100.0100.0100.00.00.0100.0100.0100.0

us-gaap:DebtInstrumentCarryingAmount



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-09-30
Value4360436035603685368536853085308530853085308530852585258524602460246024602460246024602460246024602460246024602460246019601960221022102210221222122172
Percentage of DebtInstrumentCarryingAmount100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DebtInstrument

ato:Unsecured2.625SeniorNotesdue2029



Period End2020-03-312019-12-312019-09-30
Value3003000
Percentage of DebtInstrumentCarryingAmount6.96.90.0

ato:Unsecured3.375SeniorNotesdue2049



Period End2020-03-312019-12-312019-09-30
Value5005000
Percentage of DebtInstrumentCarryingAmount11.511.50.0

ato:Unsecured4.125SeniorNotesdue2049



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312019-03-042018-09-30
Value4504504504504504500
Percentage of DebtInstrumentCarryingAmount10.310.312.612.212.20.00.0

ato:Unsecured4.30SeniorNotesdue2048



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-10-042018-09-30
Value6006006006006006006000
Percentage of DebtInstrumentCarryingAmount13.813.816.916.316.316.30.00.0

ato:UnsecuredSeniorNotesDue2027



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-09-30
Value5005005005005005005005005005005005000
Percentage of DebtInstrumentCarryingAmount11.511.514.013.613.613.616.216.216.216.216.216.20.0

ato:UnsecuredSeniorNotesDue2041



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-09-30
Value4004004004004004004004004004004004004004004004004004004004004004004004004004004004004004004004004004004004000
Percentage of DebtInstrumentCarryingAmount9.29.211.210.910.910.913.013.013.013.013.013.015.515.516.316.316.316.316.316.316.316.316.316.316.316.316.316.316.320.420.418.118.118.118.118.10.0

ato:UnsecuredSeniorNotesDue2043



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-09-30
Value5005005005005005005005005005005005005005005005005005005005005005005005005005005005005000
Percentage of DebtInstrumentCarryingAmount11.511.514.013.613.613.616.216.216.216.216.216.219.319.320.320.320.320.320.320.320.320.320.320.320.320.320.320.320.30.0

ato:UnsecuredSeniorNotesDue2044



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-10-152014-09-30
Value7507507507507507507507507507507507505005005005005005005005005005005000
Percentage of DebtInstrumentCarryingAmount17.217.221.120.420.420.424.324.324.324.324.324.319.319.320.320.320.320.320.320.320.320.30.00.0

us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType

us-gaap:DebtInstrumentFaceAmount

ato:A200MillionTermLoanAgreement, us-gaap:SecuredDebt, us-gaap:SubsequentEvent



Period End2020-04-09
Value200
Percentage of DebtInstrumentFaceAmount100.0

us-gaap:DebtInstrumentUnamortizedDiscountPremiumNet



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-09-30
Value00000-1-4-4-4-4-4-44
Percentage of DebtInstrumentUnamortizedDiscountPremiumNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredFinanceCostsNet



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-09-30
Value37373030312620212121222216161617
Percentage of DeferredFinanceCostsNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredIncomeTaxLiabilitiesNet



Period End2020-03-312019-12-312019-09-30
Value142113521300
Percentage of DeferredIncomeTaxLiabilitiesNet100.0100.0100.0

us-gaap:Range, us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsRemainderOfFiscalYear

srt:Maximum, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-31
Value20
Percentage of DefinedBenefitPlanExpectedFutureEmployerContributionsRemainderOfFiscalYear100.0

srt:Minimum, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-31
Value10
Percentage of DefinedBenefitPlanExpectedFutureEmployerContributionsRemainderOfFiscalYear50.0

us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement

us-gaap:FairValueInputsLevel1



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value00000000000000000000000
Percentage of DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0100.0100.0100.0

us-gaap:FairValueInputsLevel2



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value01121310003331094456728592106158229105
Percentage of DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.02264928.61638914.3420552.0

us-gaap:DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value00000000000009432476466829314121146
Percentage of DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset0.00.00.00.00.00.00.00.00.00.00.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeAssets



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value011213100033314119719912161858
Percentage of DerivativeAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeCollateralRightToReclaimCash



Period End2020-03-312019-09-302018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-30
Value00000000036188101617227891014121623
Percentage of DerivativeCollateralRightToReclaimCash0.00.00.00.00.00.00.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation

us-gaap:DerivativeFairValueOfDerivativeAsset

us-gaap:OtherCurrentAssets, us-gaap:CommodityContract, us-gaap:Nondesignated



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value01121310002238921
Percentage of DerivativeFairValueOfDerivativeAsset100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherNoncurrentAssets, us-gaap:CommodityContract, us-gaap:Nondesignated



Period End2020-03-312019-12-312019-09-302019-06-302018-12-312018-09-302018-06-302017-12-312017-09-302016-09-30
Value0000000001
Percentage of DerivativeFairValueOfDerivativeAsset0.213.014.26.28.818.312.441.733.08.6

us-gaap:HedgingDesignation

us-gaap:Nondesignated



Period End2020-03-312019-12-312019-09-302019-06-302018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value01123100033310935
Percentage of DerivativeFairValueOfDerivativeAsset100.2113.0114.2106.2108.8118.3112.4100.0141.7133.0109.1100.0122.1166.9

us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation

us-gaap:DerivativeFairValueOfDerivativeLiability

us-gaap:OtherCurrentLiabilities, us-gaap:CommodityContract, us-gaap:Nondesignated



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value18430100020007118
Percentage of DerivativeFairValueOfDerivativeLiability100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherNoncurrentLiabilities, us-gaap:CommodityContract, us-gaap:Nondesignated



Period End2020-03-312019-12-312019-09-302019-06-302018-12-312018-09-302018-06-302017-12-312017-09-302016-09-30
Value0010000000
Percentage of DerivativeFairValueOfDerivativeLiability0.05.227.415.30.043.80.09.60.00.0

us-gaap:HedgingDesignation

us-gaap:Nondesignated



Period End2020-03-312019-12-312019-09-302019-06-302018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value1853100030008831
Percentage of DerivativeFairValueOfDerivativeLiability100.0105.2127.4115.3100.0143.8100.0100.0109.6100.0222.6100.0123.2167.5

us-gaap:DerivativeLiabilities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value1853087567686117112109117122240233185110120521389521
Percentage of DerivativeLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeLiabilityFairValueGrossAssetAndRightToReclaimCashOffset



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value000000000000010782869010512512419425472
Percentage of DerivativeLiabilityFairValueGrossAssetAndRightToReclaimCashOffset0.00.00.00.00.00.00.00.00.00.00.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement

us-gaap:FairValueInputsLevel1



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value00000000000000000000000
Percentage of DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0100.0100.0100.0

us-gaap:FairValueInputsLevel2



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value185308756768611711210911723032331927621524617633235093
Percentage of DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.04748500.02695353.8782500.0

us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation

us-gaap:DerivativeNonmonetaryNotionalAmountPercentOfRequiredNeedCoverage

ato:GasPurchases, us-gaap:CommodityContract, us-gaap:Nondesignated



Period End2020-03-312019-12-312019-09-30
Value0.490.490.33
Percentage of DerivativeNonmonetaryNotionalAmountPercentOfRequiredNeedCoverage100.0100.0100.0

us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation, us-gaap:SubsequentEventType

us-gaap:DerivativeNotionalAmount

ato:ForwardInterestRateSwap1, us-gaap:DesignatedAsHedgingInstrument, us-gaap:SubsequentEvent



Period End2020-04-01
Value500
Percentage of DerivativeNotionalAmount100.0

ato:ForwardInterestRateSwap2, us-gaap:DesignatedAsHedgingInstrument, us-gaap:SubsequentEvent



Period End2020-04-01
Value450
Percentage of DerivativeNotionalAmount90.0

us-gaap:EnergyRelatedInventoryGasStoredUnderground



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value68115130106781461651268916318415112016323324419023623621314327727820712428624420919727425623922132528925622800
Percentage of EnergyRelatedInventoryGasStoredUnderground100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FinancialInstrument

us-gaap:EquitySecuritiesFvNi

us-gaap:FairValueInputsLevel1, us-gaap:EquitySecurities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value35444143423742
Percentage of EquitySecuritiesFvNi100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueInputsLevel1, us-gaap:FixedIncomeFunds



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value25262525212121
Percentage of EquitySecuritiesFvNi72.358.862.758.951.757.850.4

us-gaap:FairValueInputsLevel2, us-gaap:MoneyMarketFunds



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value1121233
Percentage of EquitySecuritiesFvNi5.13.36.33.15.88.99.0

us-gaap:FinancialInstrument

us-gaap:EquitySecurities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value35444143423742
Percentage of EquitySecuritiesFvNi100.0100.0100.0100.0100.0100.0100.0

us-gaap:FixedIncomeFunds



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value25262525212121
Percentage of EquitySecuritiesFvNi72.358.862.758.951.757.850.4

us-gaap:MoneyMarketFunds



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value1121233
Percentage of EquitySecuritiesFvNi5.13.36.33.15.88.99.0

us-gaap:FinanceLeaseLiability



Period End2020-03-312019-12-312019-09-30
Value620
Percentage of FinanceLeaseLiability100.0100.00.0

us-gaap:FinanceLeaseLiabilityCurrent



Period End2020-03-312019-12-31
Value131000.050000.0
Percentage of FinanceLeaseLiabilityCurrent100.0100.0

us-gaap:FinanceLeaseLiabilityNoncurrent



Period End2020-03-312019-12-31
Value62
Percentage of FinanceLeaseLiabilityNoncurrent100.0100.0

us-gaap:ForwardContractIndexedToIssuersEquitySettlementAlternativesCashAtFairValue



Period End2020-03-312019-06-302019-03-312018-12-312018-09-30
Value4184094032450
Percentage of ForwardContractIndexedToIssuersEquitySettlementAlternativesCashAtFairValue100.0100.0100.0100.00.0

us-gaap:ForwardContractIndexedToIssuersEquityType

ato:ForwardSalesEquityAgreementIssuedQuarterendedDecember312019



Period End2020-03-31
Value36
Percentage of ForwardContractIndexedToIssuersEquitySettlementAlternativesCashAtFairValue8.7

ato:ForwardSalesEquityAgreementIssuedQuarterendedJune302019



Period End2020-03-31
Value48
Percentage of ForwardContractIndexedToIssuersEquitySettlementAlternativesCashAtFairValue11.7

ato:ForwardSalesEquityAgreementIssuedQuarterendedMarch312020



Period End2020-03-31
Value180
Percentage of ForwardContractIndexedToIssuersEquitySettlementAlternativesCashAtFairValue43.0

ato:ForwardSalesEquityAgreementIssuedQuarterendedSeptember302019



Period End2020-03-31
Value153
Percentage of ForwardContractIndexedToIssuersEquitySettlementAlternativesCashAtFairValue36.7

us-gaap:SubsidiarySaleOfStock

ato:AtTheMarket



Period End2020-03-312019-12-312019-09-30
Value21936425
Percentage of ForwardContractIndexedToIssuersEquitySettlementAlternativesCashAtFairValue52.50.00.0

ato:ForwardSalesEquityAgreements



Period End2020-03-312019-12-312019-09-302018-12-312018-11-30
Value418239463247247
Percentage of ForwardContractIndexedToIssuersEquitySettlementAlternativesCashAtFairValue100.00.00.0100.90.0

us-gaap:ForwardContractIndexedToIssuersEquitySettlementAlternativesSharesAtFairValue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value3244420
Percentage of ForwardContractIndexedToIssuersEquitySettlementAlternativesSharesAtFairValue100.0100.0100.0100.0100.0100.00.0

us-gaap:ForwardContractIndexedToIssuersEquityType

ato:ForwardSalesEquityAgreementIssuedQuarterendedDecember312019



Period End2020-03-31
Value0
Percentage of ForwardContractIndexedToIssuersEquitySettlementAlternativesSharesAtFairValue8.9

ato:ForwardSalesEquityAgreementIssuedQuarterendedJune302019



Period End2020-03-31
Value0
Percentage of ForwardContractIndexedToIssuersEquitySettlementAlternativesSharesAtFairValue12.8

ato:ForwardSalesEquityAgreementIssuedQuarterendedMarch312020



Period End2020-03-31
Value1
Percentage of ForwardContractIndexedToIssuersEquitySettlementAlternativesSharesAtFairValue40.8

ato:ForwardSalesEquityAgreementIssuedQuarterendedSeptember302019



Period End2020-03-31
Value1
Percentage of ForwardContractIndexedToIssuersEquitySettlementAlternativesSharesAtFairValue37.5

us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-12-312013-09-302012-12-31
Value15001500150015001500150015001500150015001500150015001600130013001300130013001300130013001000100010001000950
Percentage of LineOfCreditFacilityMaximumBorrowingCapacity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CreditFacility, us-gaap:DebtInstrument, us-gaap:SubsequentEventType

us-gaap:CommercialPaper, ato:FiveYearUnsecuredRevolvingCreditAgreement, us-gaap:SubsequentEvent



Period End2020-04-30
Value1500
Percentage of LineOfCreditFacilityMaximumBorrowingCapacity0.0

us-gaap:LineOfCredit, ato:A50MillionBankLoanAgreement, us-gaap:SubsequentEvent



Period End2020-04-01
Value50
Percentage of LineOfCreditFacilityMaximumBorrowingCapacity0.0

us-gaap:RevolvingCreditFacility, ato:A50MillionRevolvingCreditFacility, us-gaap:SubsequentEvent



Period End2020-04-30
Value50
Percentage of LineOfCreditFacilityMaximumBorrowingCapacity0.0

us-gaap:RevolvingCreditFacility, ato:A600MillionRevolvingCreditFacility, us-gaap:SubsequentEvent



Period End2020-04-23
Value600
Percentage of LineOfCreditFacilityMaximumBorrowingCapacity0.0

us-gaap:CreditFacility, us-gaap:SubsequentEventType

us-gaap:RevolvingCreditFacility, us-gaap:SubsequentEvent



Period End2020-04-30
Value2200
Percentage of LineOfCreditFacilityMaximumBorrowingCapacity0.0

us-gaap:LongTermDebtAndCapitalLeaseObligations



Period End2020-03-312019-12-312019-09-30
Value432843243529
Percentage of LongTermDebtAndCapitalLeaseObligations100.0100.0100.0

us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent



Period End2020-03-312019-12-312019-09-30
Value131000.050000.00.0
Percentage of LongTermDebtAndCapitalLeaseObligationsCurrent100.0100.00.0

us-gaap:LongTermDebtAndCapitalLeaseObligationsIncludingCurrentMaturities



Period End2020-03-312019-12-312019-09-30
Value436643623560
Percentage of LongTermDebtAndCapitalLeaseObligationsIncludingCurrentMaturities100.0100.0100.0

us-gaap:LongTermDebtFairValue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-09-30
Value486349274216414439653161
Percentage of LongTermDebtFairValue100.0100.0100.0100.0100.0100.0

us-gaap:OperatingLeaseLiability



Period End2020-03-312019-12-31
Value231231
Percentage of OperatingLeaseLiability100.0100.0

us-gaap:OperatingLeaseLiabilityCurrent



Period End2020-03-312019-12-31
Value3130
Percentage of OperatingLeaseLiabilityCurrent100.0100.0

us-gaap:OperatingLeaseLiabilityNoncurrent



Period End2020-03-312019-12-31
Value199200
Percentage of OperatingLeaseLiabilityNoncurrent100.0100.0

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-09-30
Value24962441239223472300225021962188214220902042202819871939189019181882184918091721
Percentage of PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentNet



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-09-30
Value1254812250117871134010971106981037110071976195189259892487388552828080537839765374306725
Percentage of PublicUtilitiesPropertyPlantAndEquipmentNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ato:DistributionSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-09-30
Value936490838737840481267889764474276849
Percentage of PublicUtilitiesPropertyPlantAndEquipmentNet74.674.274.174.174.173.773.773.774.0

us-gaap:OperatingSegments, ato:PipelineandStorageSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-09-30
Value318331663050293628442808272626442409
Percentage of PublicUtilitiesPropertyPlantAndEquipmentNet25.425.825.925.925.926.326.326.326.0

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentPlantInService



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-09-30
Value15044146911418013687132721294812567122601190311609113011095210725104921017199729722950292408447
Percentage of PublicUtilitiesPropertyPlantAndEquipmentPlantInService100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RegulatoryAssets



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-09-302011-06-302010-09-30
Value266242284164158142143129121134176216237237263184201205192202230267250250277272286327337366368290294312271277
Percentage of RegulatoryAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RegulatoryAsset

ato:InfrastructureMechanisms



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-09-30
Value1421081311111078596776554463861494231534332244526
Percentage of RegulatoryAssets53.345.046.467.567.959.867.359.653.640.726.317.825.920.716.216.826.721.117.112.019.610.8

ato:RateCaseCosts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-09-30
Value2111112333221111111112345566654444454
Percentage of RegulatoryAssets0.80.40.50.91.01.31.92.32.52.41.51.10.60.60.60.90.90.80.80.70.50.91.51.81.82.12.21.91.91.61.31.51.50.01.62.01.6

us-gaap:DeferredFuelCosts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-09-30
Value01023731110018651691845311691220
Percentage of RegulatoryAssets0.04.38.44.42.28.21.30.30.013.837.27.64.07.717.11.80.67.95.10.71.18.0

us-gaap:DeferredProjectCosts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-09-30
Value2727262523222016141211109873
Percentage of RegulatoryAssets10.411.39.315.415.115.514.213.112.09.76.64.83.83.42.81.6

us-gaap:LossOnReacquiredDebt



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-09-30
Value56677889910111112131314151516161718
Percentage of RegulatoryAssets2.12.52.34.34.75.76.17.28.27.96.35.55.35.55.27.87.57.68.58.47.67.5

us-gaap:OtherRegulatoryAssetsLiabilities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-09-30
Value74846665891091313132016119464
Percentage of RegulatoryAssets2.91.83.02.74.24.54.74.06.67.25.74.65.65.55.111.38.15.85.12.42.81.9

us-gaap:PensionAndOtherPostretirementPlansCosts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-09-30
Value808386877617202426122125128132110113116121149153162
Percentage of RegulatoryAssets30.434.630.34.94.95.04.513.517.218.315.256.452.954.350.259.756.356.763.073.766.465.0

us-gaap:RegulatoryLiabilities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-09-302011-06-302010-09-30
Value1458139513861489153915121510149914931308555529559517514535570529524581646571545521528489453464485464488490492486457430
Percentage of RegulatoryLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:BalanceSheetLocation, us-gaap:RegulatoryLiability

us-gaap:OtherCurrentLiabilities, us-gaap:DeferredIncomeTaxCharges



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value21212121242354
Percentage of RegulatoryLiabilities1.51.61.51.51.61.50.30.3

us-gaap:RegulatoryLiability

ato:RegulatoryClauseRevenuesOverRecovered



Period End2020-03-312019-12-312019-09-302019-03-312018-12-312018-09-302017-09-30
Value6872784844350
Percentage of RegulatoryLiabilities4.75.25.73.23.02.30.0

ato:RegulatoryCostofServiceReserve



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-09-30
Value34566192230290
Percentage of RegulatoryLiabilities0.30.30.40.40.41.31.52.11.90.0

us-gaap:AssetRetirementObligationCosts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-09-30
Value1717171212121212121212131313139999489490441425425427426433459449463469464429381
Percentage of RegulatoryLiabilities1.21.21.20.90.80.90.90.90.91.02.32.52.42.62.61.71.61.71.785.589.984.780.486.894.391.889.494.191.794.20.095.493.888.5

us-gaap:DeferredFuelCosts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-09-30
Value1154214661248594159167191516491720346832288113535
Percentage of RegulatoryLiabilities7.93.01.04.48.15.76.310.611.21.52.83.28.93.43.96.412.16.25.414.020.96.4

us-gaap:DeferredIncomeTaxCharges



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value7157217267317367407447377377460
Percentage of RegulatoryLiabilities49.151.752.449.147.849.049.349.249.457.00.0

us-gaap:OtherRegulatoryAssetsLiabilities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-09-30
Value17171631614991475610645533121314
Percentage of RegulatoryLiabilities1.21.31.20.21.10.90.60.71.00.61.11.31.91.30.81.00.90.60.72.22.12.7

us-gaap:RemovalCosts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-09-30
Value521519528526524523522528526520521492486479476486486482483486489490
Percentage of RegulatoryLiabilities35.737.238.235.334.034.634.635.335.339.893.893.086.892.792.690.985.391.192.283.775.689.9

us-gaap:ShortTermBorrowings



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value19904647400575244129336447258670940829670626763457251224550196006893671412328305702131733892060000
Percentage of ShortTermBorrowings100.00.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0

Line plots across dimensions of each concept

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments


us-gaap:Revenues us-gaap:StatementBusinessSegments


us-gaap:Revenues us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments


us-gaap:CostOfRevenue us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments


us-gaap:CostOfRevenue us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments


us-gaap:InterestExpense us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments


us-gaap:OperatingIncomeLoss us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments


us-gaap:InterestExpense us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments


us-gaap:OtherNonoperatingIncomeExpense us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments


us-gaap:IncomeTaxExpenseBenefit us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments


us-gaap:NetIncomeLoss us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments


us-gaap:Assets us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments


us-gaap:StockholdersEquity us-gaap:StatementEquityComponents


us-gaap:StockholdersEquity us-gaap:StatementEquityComponents


us-gaap:NetIncomeLoss us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments


us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:StatementScenario, us-gaap:DebtInstrument