Number of multi value projects approved by Midcontinent Independent System Operator, Inc.

No definition available.

Name:	duk_ApprovedMVPProposals
Namespace Prefix:	duk_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Approved Return on Equity Percentage Adder

+ References

No definition available.

+ Details

Name:	duk_ApprovedReturnonEquityPercentageAdder
Namespace Prefix:	duk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Coal-Fired Generation Capacity, in Megawatts

+ References

No definition available.

+ Details

Name:	duk_CoalFiredGenerationCapacityPotentialPlantsToBeRetiredInMegawatts
Namespace Prefix:	duk_
Data Type:	num:powerItemType
Balance Type:	na
Period Type:	duration

- Definition

Estimated Capital Cost Excluding AFUDC

+ References

No definition available.

+ Details

Name:	duk_EstimatedCapitalCostExcludingAFUDC
Namespace Prefix:	duk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Estimated capital cost of new utility plant including AFUDC.

+ References

No definition available.

+ Details

Name:	duk_EstimatedCapitalCostIncludingAfudc
Namespace Prefix:	duk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The estimated cash outflow associated with contributions to an equity method investment (EMI) to fund the EMI's development and construction of a new natural gas pipeline.

+ References

No definition available.

+ Details

Name:	duk_EstimatedContributions
Namespace Prefix:	duk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Estimated capital cost of new project

+ References

No definition available.

+ Details

Name:	duk_Estimatedcapitalcost
Namespace Prefix:	duk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

MISO's estimate of Duke Energy Ohio's exit obligation to MISO

+ References

No definition available.

+ Details

Name:	duk_ExitObligationEstimate
Namespace Prefix:	duk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Percent of federally mandated costs to be recovered through a periodic rate adjustment

+ References

No definition available.

+ Details

Name:	duk_FederalMandateCostsRecoveredThroughTrackerMechanism
Namespace Prefix:	duk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percent of federally mandated costs, including carrying costs, to be recovered in future rate case

+ References

No definition available.

+ Details

Name:	duk_FederallyMandatedCostsRecoveredInFutureRateCase
Namespace Prefix:	duk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Generation facilities to be retired, net

+ References

No definition available.

+ Details

Name:	duk_GenerationFacilitiesToBeRetiredNet
Namespace Prefix:	duk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage Recovered Through Future Rate Case

+ References

No definition available.

+ Details

Name:	duk_PercentageRecoveredThroughFutureRateCase
Namespace Prefix:	duk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of Costs Recovered through Existing Rider

+ References

No definition available.

+ Details

Name:	duk_PercentageofCostsRecoveredthroughExistingRider
Namespace Prefix:	duk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of regulatory costs not yet approved by the regulatory authority.

+ References

No definition available.

+ Details

Name:	us-gaap_AmountOfRegulatoryCostsNotYetApproved
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Revenue derived from the regulated (by a federal, state, or local government or agency) generation, transmission and distribution of electricity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1(b))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

Name:	us-gaap_ElectricDomesticRegulatedRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The proportionate share of interest (percent) in a jointly owned utility plant.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 360
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 10.C)
-URI http://asc.fasb.org/extlink&oid=6500719&loc=d3e659983-123033

+ Details

Name:	us-gaap_JointlyOwnedUtilityPlantProportionateOwnershipShare
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Period covered by the long-term purchase commitment, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_LongtermPurchaseCommitmentPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of public utility's approved rate increase (decrease) by regulatory agency.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesApprovedRateIncreaseDecreaseAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Percentage of public utility's approved return on equity.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesApprovedReturnOnEquityPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesGeneralDisclosuresLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Discloses the interest rate related to debt for plant construction for an electric utility using an intermediary for each period for which an income statement is presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 810
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 10.A)
-URI http://asc.fasb.org/extlink&oid=6501539&loc=d3e661063-123039

+ Details

Name:	us-gaap_PublicUtilitiesPropertyPlantAndEquipmentInterestRateOnIntermediaryDebtForElectricUtilityPlantConstruction
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Period end amount of total net PPE.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of public utility's amended requested rate increase (decrease) with regulatory agency.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesRequestedRateIncreaseDecreaseAmendedAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of public utility's requested rate increase (decrease) with regulatory agency.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesRequestedRateIncreaseDecreaseAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Percentage of public utility's requested return on equity.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesRequestedReturnOnEquityPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 340
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382

+ Details

Name:	us-gaap_RegulatoryAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB TOPIC 5.P.4(b))
-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

+ Details

Name:	us-gaap_RestructuringReserve
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=duk_GenerationFacilitiesToBeRetiredMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_JointlyOwnedUtilityPlantAxis=duk_AtlanticCoastPipelineACPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_JointlyOwnedUtilityPlantAxis=duk_SabalTrailTransmissionPipelineMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_JointlyOwnedUtilityPlantAxis=duk_ConstitutionPipelineMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=duk_DominionResourcesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=duk_SouthernCompanyGasMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=duk_SpectraEnergyPartnersLPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=duk_NextEraMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=duk_WilliamsPartnersL.P.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=duk_DukeEnergyCarolinasMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilityAxis=duk_WilliamStatesLeeCombinedCycleFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_JointlyOwnedUtilityPlantAxis=duk_NCEMCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=duk_ProgressEnergyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=duk_DukeEnergyProgressMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilityAxis=duk_AshevillePlantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=duk_DukeEnergyFloridaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=duk_DukeEnergyOhioMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilityAxis=duk_RegionalTransmissionOrganizationRealignmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=duk_DukeEnergyIndianaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=duk_PiedmontNaturalGasMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_StormCostDeferralsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RegulatoryAgencyAxis=duk_NCUCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_WesternCarolinasModernizationPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_HinesChillerUprateProjectMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RegulatoryAgencyAxis=duk_FPSCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_LevyNuclearProjectMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_EastBendCoalAshBasinFilingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RegulatoryAgencyAxis=duk_KPSCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_A2017BaseRateCaseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RegulatoryAgencyAxis=duk_PublicUtilitiesCommissionOfOhioMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_NaturalGasPipelineExtensionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_AdvancedMeteringInfrastructureProjectMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_AcceleratedNaturalGasServiceLineReplacementRiderMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_EnergyEfficiencyandPeakDemandReductionProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_MGPRemediationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_CoalCombustionResidualPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RegulatoryAgencyAxis=duk_IURCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_FERCTransmissionRatesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RegulatoryAgencyAxis=duk_FederalEnergyRegulatoryCommissionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_FERCComplaintMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_FERCComplaint1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_FERCComplaint2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_NCUCIMRPetitionFiledOctober2016Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_NCUCIMRPetitionFiledMay2017Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_TPUCPetitionFiledIMRNovember2016Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RegulatoryAgencyAxis=duk_TPUCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Regulatory Matters (Narrative) (Details) $ in Millions		1 Months Ended	3 Months Ended
Regulatory Matters (Narrative) (Details) $ in Millions	May 01, 2017 USD ($)	Dec. 31, 2015 USD ($)	Mar. 31, 2017 USD ($) MW	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)
Public Utilities, General Disclosures [Line Items]
Public Utilities, Property, Plant and Equipment, Net			$ 83,516.0		$ 82,520.0
Generation Facilities To Be Retired Net			508.0		529.0
Electric Domestic Regulated Revenue			$ 4,913.0	$ 5,053.0
Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) \| MW			1,738
Public Utilities, Property, Plant and Equipment, Net			$ 419.0
Atlantic Coast Pipeline (ACP) [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage			47.00%
Long-term Purchase Commitment, Period			20 years
Sabal Trail Transmission Pipeline [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage			7.50%
Estimated capital cost			$ 3,200.0
Long-term Purchase Commitment, Period			25 years
Constitution Pipeline [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage			24.00%
Estimated Contributions			$ 229.0
Minimum [Member] \| Atlantic Coast Pipeline (ACP) [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost			5,000.0
Maximum [Member] \| Atlantic Coast Pipeline (ACP) [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost			$ 5,500.0
Dominion Resources [Member] \| Atlantic Coast Pipeline (ACP) [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage			48.00%
Southern Company Gas [Member] \| Atlantic Coast Pipeline (ACP) [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage			5.00%
Spectra Energy [Member] \| Sabal Trail Transmission Pipeline [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage			50.00%
NextEra [Member] \| Sabal Trail Transmission Pipeline [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage			42.50%
Williams Partners L.P. [Member] \| Constitution Pipeline [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage			41.00%
Duke Energy Carolinas [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Property, Plant and Equipment, Net			$ 26,951.0		26,762.0
Duke Energy Carolinas [Member] \| William States Lee Combined Cycle Facility [Member] \| NCEMC [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost of new utility plant, including AFUDC			$ 600.0
Joint owner ownership percentage			13.00%
Progress Energy [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Property, Plant and Equipment, Net			$ 30,792.0		30,181.0
Generation Facilities To Be Retired Net			508.0		529.0
Duke Energy Progress [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Property, Plant and Equipment, Net			18,561.0		18,387.0
Generation Facilities To Be Retired Net			$ 508.0		529.0
Duke Energy Progress [Member] \| Asheville Plant [Member] \| Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) \| MW			376
Generation Facilities To Be Retired Net			$ 471.0		492.0
Duke Energy Florida [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Property, Plant and Equipment, Net			12,228.0		11,790.0
Duke Energy Ohio [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Property, Plant and Equipment, Net			5,625.0		5,547.0
Electric Domestic Regulated Revenue			337.0	$ 340.0
Duke Energy Ohio [Member] \| Regional Transmission Organization Realignment [Member]
Public Utilities, General Disclosures [Line Items]
Exit obligation			90.0		90.0
Regulatory Assets			$ 71.0		71.0
Approved MVP Proposals			17
MISO estimate of Duke Energy Ohio's MVP obligation			$ 2,700.0
Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Property, Plant and Equipment, Net			9,985.0		9,924.0
Piedmont Natural Gas [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Property, Plant and Equipment, Net			4,907.0		$ 4,814.0
Storm Cost Deferrals [Member] \| NCUC [Member] \| Duke Energy Progress [Member]
Public Utilities, General Disclosures [Line Items]
Amount of Regulatory Costs Not yet Approved			116.0
Western Carolinas Modernization Plan [Member] \| NCUC [Member] \| Duke Energy Progress [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost			893.0
Hines Chiller Uprate Project [Member] \| Duke Energy Florida [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost			150.0
Hines Chiller Uprate Project [Member] \| FPSC [Member] \| Duke Energy Florida [Member]
Public Utilities, General Disclosures [Line Items]
Approved Rate Increase (Decrease), Amount			19.0
Levy Nuclear Project [Member] \| FPSC [Member] \| Duke Energy Florida [Member]
Public Utilities, General Disclosures [Line Items]
Requested Rate Increase (Decrease), Amount			82.0
East Bend Coal Ash Basin Filing [Member] \| KPSC [Member] \| Duke Energy Ohio [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost			93.0
2017 Base Rate Case [Member] \| PUCO [Member] \| Duke Energy Ohio [Member]
Public Utilities, General Disclosures [Line Items]
Requested Rate Increase (Decrease), Amount			$ 15.0
Requested Return on Equity, Percentage			10.40%
Natural Gas Pipeline Extension [Member] \| PUCO [Member] \| Duke Energy Ohio [Member] \| Minimum [Member]
Public Utilities, General Disclosures [Line Items]
Estimated Capital Cost Excluding AFUDC			$ 86.0
Natural Gas Pipeline Extension [Member] \| PUCO [Member] \| Duke Energy Ohio [Member] \| Maximum [Member]
Public Utilities, General Disclosures [Line Items]
Estimated Capital Cost Excluding AFUDC			110.0
Advanced Metering Infrastructure Project [Member] \| KPSC [Member] \| Duke Energy Ohio [Member]
Public Utilities, General Disclosures [Line Items]
Amount of Regulatory Costs Not yet Approved			10.0
Estimated capital cost			49.0
Accelerated Natural Gas Service Line Replacement Rider [Member] \| PUCO [Member] \| Duke Energy Ohio [Member]
Public Utilities, General Disclosures [Line Items]
Amount of Regulatory Costs Not yet Approved			240.0
Energy Efficiency and Peak Demand Reduction Program [Member] \| PUCO [Member] \| Duke Energy Ohio [Member]
Public Utilities, General Disclosures [Line Items]
Electric Domestic Regulated Revenue		$ 20.0
MGP Remediation [Member] \| PUCO [Member] \| Duke Energy Ohio [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets			100.0
Coal Combustion Residual Plan [Member] \| IURC [Member] \| Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Requested Rate Increase (Decrease), Amount			$ 380.0
Federal Mandate Costs Recovered Through Tracker Mechanism			80.00%
Federally Mandated Costs Recovered In Future Rate Case			20.00%
Percentage of Costs Recovered through Existing Rider			60.00%
Percentage Recovered Through Future Rate Case			40.00%
Interest Rate on Intermediary Debt for Electric Utility Plant Construction			4.73%
Requested Rate Increase (Decrease), Amended, Amount			$ 365.0
FERC Transmission Rates [Member] \| Federal Energy Regulatory Commission [Member] \| Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage			12.38%
Approved Return on Equity Percentage Adder			0.50%
FERC Complaint [Member] \| Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Requested Return on Equity, Percentage			8.67%
FERC Complaint 1 [Member] \| Federal Energy Regulatory Commission [Member] \| Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage			10.32%
FERC Complaint 2 [Member] \| Federal Energy Regulatory Commission [Member] \| Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Requested Return on Equity, Percentage			9.70%
NCUC IMR Petition Filed October 2016 [Member] \| NCUC [Member] \| Piedmont Natural Gas [Member]
Public Utilities, General Disclosures [Line Items]
Approved Rate Increase (Decrease), Amount			$ 8.0
NCUC IMR Petition Filed May 2017 [Member] \| NCUC [Member] \| Piedmont Natural Gas [Member] \| Subsequent Event [Member]
Public Utilities, General Disclosures [Line Items]
Requested Rate Increase (Decrease), Amount	$ 11.6
TPUC Petition Filed IMR November 2016 [Member] \| TPUC [Member] \| Piedmont Natural Gas [Member]
Public Utilities, General Disclosures [Line Items]
Approved Rate Increase (Decrease), Amount			$ 1.7