Allowed Storm Reserve

No definition available.

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

- Definition

Asset Impairment Charge Reversal

+ References

No definition available.

+ Details

Name:	duk_AssetImpairmentChargeReversal
Namespace Prefix:	duk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Customers Experiencing Outages

+ References

No definition available.

+ Details

Name:	duk_CustomersExperiencingOutages
Namespace Prefix:	duk_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Estimated Capital Cost Including Afudc

+ References

No definition available.

+ Details

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

- Definition

Estimated Storm Costs - Capital and Operation Maintenance

+ References

No definition available.

+ Details

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

- Definition

Increase (Decrease) In Storm Reserve

+ References

No definition available.

+ Details

Name:	duk_IncreaseDecreaseInStormReserve
Namespace Prefix:	duk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Plant Capacity

+ References

No definition available.

+ Details

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

- Definition

Public Utilities, Regulatory Asset, Amount Of Recovery Costs Sought

+ References

No definition available.

+ Details

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

- Definition

Tax Act Annual Tax Savings requested rate decrease as a result of the 2017 Federal Tax Cut and Jobs Act

+ References

No definition available.

+ Details

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

- Definition

Tax Act Excess Deferred Tax Amortization requested rate decrease as a result of the 2017 Federal Tax Cut and Jobs Act

+ References

No definition available.

+ Details

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

- Definition

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2420-110228

+ Details

Name:	us-gaap_AssetImpairmentCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(14))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(8))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(13))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- 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

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

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 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

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://fasb.org/us-gaap/role/ref/legacyRef
-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

The amount of operating expenses for the period that are associated with the utility's normal revenue producing operation; including selling, general, and administrative expenses, costs incurred for routine plant repairs and maintenance, and operations.

+ References

No definition available.

+ Details

Name:	us-gaap_UtilitiesOperatingExpenseMaintenanceOperationsAndOtherCostsAndExpenses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_PublicUtilityAxis=duk_CrystalRiverUnits3and4Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=duk_SecondRevisedAndRestatedStipulationAndSettlementAgreement2017Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_RegulatoryAssetAxis=us-gaap_StormCostsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Regulatory Matters (Duke Energy Florida Narrative) (Details) customer in Thousands, $ in Millions						1 Months Ended	3 Months Ended			12 Months Ended
	Jun. 13, 2019 USD ($)	Mar. 25, 2019 USD ($)	Dec. 27, 2018 USD ($)	Jul. 31, 2018 USD ($)	May 31, 2018 USD ($)	Jan. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2018 USD ($) MW	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Nov. 22, 2019 USD ($)	Jan. 29, 2019 USD ($)	Oct. 31, 2018 customer	Sep. 30, 2017 customer	Oct. 31, 2015 USD ($)
Public Utilities, General Disclosures [Line Items]
Net property, plant and equipment							$ 102,127		$ 91,694	$ 102,127	$ 91,694
Operation, maintenance and other										6,066	6,463	$ 5,944
Regulatory assets							15,018		15,622	15,018	15,622
Remaining net book value							102,127		91,694	102,127	91,694
Impairment charges										(8)	402	282
Reduction of prior year impairment							(14)	$ 25		11
Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Net property, plant and equipment							15,221		13,824	15,221	13,824
Operation, maintenance and other										1,034	1,025	853
Regulatory assets							2,613		2,888	2,613	2,888
Remaining net book value							15,221		13,824	15,221	13,824
Impairment charges										(36)	54	$ 138
Storm Restoration Cost Recovery \| Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Customers experiencing outages \| customer																1,000
Estimated storm costs, capital and operation maintenance														$ 508
Allowed storm reserve					$ 132
Net property, plant and equipment	$ 18
Operation, maintenance and other	6
Increase (decrease) in storm reserve	$ (24)
Hurricane Michael Storm Damage \| Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Customers experiencing outages \| customer															72
Estimated storm costs, capital and operation maintenance							311			311
Amount of recovery costs sought													$ 191
Net property, plant and equipment							107		$ 35	107	35
Hurricane Dorian Storm Damage \| Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Estimated storm costs, capital and operation maintenance							167			167
FPSC \| Storm Restoration Cost Recovery \| Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Estimated storm costs, capital and operation maintenance					510
FPSC \| Federal Tax Act Impacts \| Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Amount of tax act annual tax savings requested rate decrease			$ 4		134
Amount of tax act excess deferred tax amortization requested rate decrease			71		67
FPSC \| Federal Tax Act Impacts Revenue Requirement \| Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease)					201
Crystal River Units 3 and 4 \| FPSC \| Federal Tax Act Impacts Revenue Requirement \| Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Remaining net book value					50
Citrus County Combined Cycle Facility \| Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Plant capacity \| MW									1,640
Estimated capital cost including Afudc							1,500		$ 1,600	1,500	1,600						$ 1,500
Impairment charges									60
Reduction of prior year impairment										36
Hamilton Project \| FPSC \| Second Revised And Restated Stipulation And Settlement Agreement 2017 \| Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Approved rate increase (decrease) amount by state commission						$ (15)
Columbia Project \| FPSC \| Second Revised And Restated Stipulation And Settlement Agreement 2017 \| Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease)				$ (14)
Trenton Generation Project \| FPSC \| Second Revised And Restated Stipulation And Settlement Agreement 2017 \| Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease)		$ 13
Lake Placid Generation Project \| FPSC \| Second Revised And Restated Stipulation And Settlement Agreement 2017 \| Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease)		8
DeBary Solar Project \| FPSC \| Second Revised And Restated Stipulation And Settlement Agreement 2017 \| Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease)		$ 11
Storm cost deferrals
Public Utilities, General Disclosures [Line Items]
Regulatory assets							1,399		1,117	1,399	1,117
Storm cost deferrals \| Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Regulatory assets							413		382	413	382
Storm cost deferrals \| Storm Restoration Cost Recovery \| Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Regulatory assets							43		217	43	217
Storm cost deferrals \| Hurricane Michael Storm Damage \| Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Regulatory assets							$ 204		$ 165	$ 204	$ 165
Storm cost deferrals \| FPSC \| Federal Tax Act Impacts Revenue Requirement \| Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Regulatory assets			$ 155		$ 151