Defined Benefit Plan, Maximum years of participation

No definition available.

Name:	duk_DefinedBenefitPlanMaximumyearsofparticipation
Namespace Prefix:	duk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of eligible pay per period contributed to an employee's 401(k) account in lieu of participation in Duke Energy's defined pension plans.

+ References

No definition available.

+ Details

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

- Definition

The interest rate used to adjust for the time value of money for the plan.

+ References

+ Details

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

- Definition

The increase in the fair value of plan assets from contributions made by the employer.

+ References

+ Details

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

- Details

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

- Definition

The assumed health care cost trend rate for the next year used to measure the expected cost of benefits covered by the plan (gross eligible charges). This is based upon the annual rate of change in the cost of health care benefits currently provided by the postretirement benefit plan, due to factors other than changes in the composition of the plan population by age and dependency status.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (l)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Health Care Cost Trend Rate

-URI http://asc.fasb.org/extlink&oid=6514820

+ Details

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

- Definition

The ultimate trend rate for health care costs.

+ References

+ Details

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

- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

+ Details

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

- Definition

Percentage employer matches of the employee's percentage contribution matched.

+ References

No definition available.

+ Details

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

Employee Benefit Plans (Narrative) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended			3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Sep. 30, 2014 Duke Energy Florida [Member]	Sep. 30, 2014 Duke Energy Florida [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate			4.70%
Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year		8.50%
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate		5.00%
Defined Benefit Plan, Maximum years of participation	35 years
Additional savings plan account contribution percentage for employees not participating in defined pension plans	4.00%
Eligible pay percentage	6.00%
Matching contribution percentage	100.00%
Contributions by employer				$ 27	$ 27