No definition available.

Name:	duk_AmountsRecognizedInRegulatoryAssetsAndLiabilitiesAbstract
Namespace Prefix:	duk_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The after tax amount of amortization of prior year actuarial gains and losses that are not yet recognized as a component of net periodic benefit cost, and that are recognized as increases or decreases in other comprehensive income as they arise.

+ References

No definition available.

+ Details

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

- Definition

The increase (decrease) during the reporting period in the value of other assets that are created when regulatory agencies permits public utilities to defer costs to the balance sheet.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

+ Details

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

- Definition

The increase (decrease) during the reporting period in regulated liabilities. Regulated liabilities are created when regulatory agency permits an entity to defer revenues to the balance sheet.

+ References

+ Details

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

- Definition

Amount, before tax, of cost (credit) of benefit change attributable to participants' prior service from plan amendment or plan initiation of defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (j)
-URI http://asc.fasb.org/extlink&oid=84228862&loc=SL7669646-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e637-108580

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Amount, after tax, of reclassification adjustment from accumulated other comprehensive (income) loss for prior service cost (credit) of defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e689-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e637-108580

+ Details

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

- Definition

Amount, after tax and reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan.

+ References

+ Details

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

- Definition

Amount, before tax, of gain (loss) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e637-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=84228862&loc=SL7669646-108580

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

+ Details

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

- Definition

Amount, after reclassification adjustment, of tax (expense) benefit for (increase) decrease in accumulated other comprehensive income of defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e640-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 19
-URI http://asc.fasb.org/extlink&oid=96868048&loc=SL4569616-111683

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (i-k)
-URI http://asc.fasb.org/extlink&oid=84228862&loc=SL7669646-108580

+ Details

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

- Details

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

- Details

Name:	us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanTaxStatusAxis=us-gaap_QualifiedPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanTaxStatusAxis=us-gaap_NonqualifiedPlanMember
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:	dei_LegalEntityAxis=duk_DukeEnergyProgressMember
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:	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_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Employee Benefit Plans (Amounts Recognized in Accumulated Other Comprehensive Income and Regulatory Assets and Liabilities) (Details) - USD ($) $ in Millions	2 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Oct. 31, 2016	Dec. 31, 2015	Oct. 31, 2015
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Net amount recognized in accumulated other comprehensive (income) loss		$ (3)	$ 11		$ 13
Progress Energy [Member]
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Net amount recognized in accumulated other comprehensive (income) loss		(4)	(1)		$ 10
Pension Plan [Member] \| Qualified Plan [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)		(212)	214
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Deferred income tax expense (benefit)			4
Prior year service cost (credit) arising during the year		1	(2)
Amortization of prior year actuarial gains (losses)		(7)	(7)
Net amount recognized in accumulated other comprehensive (income) loss		(6)	(5)
Pension Plan [Member] \| Nonqualified Plan [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)		5	(3)
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Deferred income tax expense (benefit)		(1)
Actuarial (gains) losses arising during the year		2	1
Prior year service cost (credit) arising during the year			(1)
Net amount recognized in accumulated other comprehensive (income) loss		1
Pension Plan [Member] \| Duke Energy Carolinas [Member] \| Qualified Plan [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)		(70)	4
Pension Plan [Member] \| Duke Energy Carolinas [Member] \| Nonqualified Plan [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)		(1)	(2)
Pension Plan [Member] \| Progress Energy [Member] \| Qualified Plan [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)		(49)	34
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Deferred income tax expense (benefit)		3
Amortization of prior year actuarial gains (losses)		(7)	(1)
Net amount recognized in accumulated other comprehensive (income) loss		(4)	(1)
Pension Plan [Member] \| Progress Energy [Member] \| Nonqualified Plan [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)		3	2
Pension Plan [Member] \| Duke Energy Progress [Member] \| Qualified Plan [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)		(37)	18
Pension Plan [Member] \| Duke Energy Progress [Member] \| Nonqualified Plan [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)		1	1
Pension Plan [Member] \| Duke Energy Florida [Member] \| Qualified Plan [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)		(11)	16
Pension Plan [Member] \| Duke Energy Florida [Member] \| Nonqualified Plan [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)		2	1
Pension Plan [Member] \| Duke Energy Ohio [Member] \| Qualified Plan [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)		9	2
Pension Plan [Member] \| Duke Energy Indiana [Member] \| Qualified Plan [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)		(19)	9
Pension Plan [Member] \| Duke Energy Indiana [Member] \| Nonqualified Plan [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)			(1)
Pension Plan [Member] \| Piedmont Natural Gas [Member] \| Qualified Plan [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	$ 34	(64)		$ 35		$ 20
Other Post-Retirement Benefit Plans [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)		71	53
Regulatory liabilities, net increase (decrease)		(27)	(114)
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Deferred income tax expense (benefit)		(1)	(2)
Actuarial (gains) losses arising during the year			3
Amortization of prior year prior service credit		3	1
Net amount recognized in accumulated other comprehensive (income) loss		2	2
Other Post-Retirement Benefit Plans [Member] \| Duke Energy Carolinas [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory liabilities, net increase (decrease)		(2)	(22)
Other Post-Retirement Benefit Plans [Member] \| Progress Energy [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)		81	47
Regulatory liabilities, net increase (decrease)			(51)
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Amortization of prior year prior service credit			1
Net amount recognized in accumulated other comprehensive (income) loss			1
Other Post-Retirement Benefit Plans [Member] \| Duke Energy Progress [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)		42	38
Regulatory liabilities, net increase (decrease)			(25)
Other Post-Retirement Benefit Plans [Member] \| Duke Energy Florida [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)		39	9
Regulatory liabilities, net increase (decrease)			(26)
Other Post-Retirement Benefit Plans [Member] \| Duke Energy Ohio [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory liabilities, net increase (decrease)		(3)	(2)
Other Post-Retirement Benefit Plans [Member] \| Duke Energy Indiana [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)		(5)	(6)
Regulatory liabilities, net increase (decrease)		(7)	$ (12)
Other Post-Retirement Benefit Plans [Member] \| Piedmont Natural Gas [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	$ (1)	$ (11)		$ 2		$ 1