Employee Benefit Plans (Information For Plans with Accumulated Benefit Obligation in Excess of Plan Assets) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Qualified Pension Plans [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	$ 702
Accumulated benefit obligation	672
Fair value of plan assets	652
Qualified Pension Plans [Member] \| Duke Energy Ohio [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	315
Accumulated benefit obligation	306
Fair value of plan assets	302
Non-Qualified Pension Plans [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	337	304
Accumulated benefit obligation	333	302
Non-Qualified Pension Plans [Member] \| Duke Energy Carolinas [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	16	15
Accumulated benefit obligation	15	15
Non-Qualified Pension Plans [Member] \| Progress Energy [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	116	140
Accumulated benefit obligation	116	140
Non-Qualified Pension Plans [Member] \| Duke Energy Progress [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	35	34
Accumulated benefit obligation	35	34
Non-Qualified Pension Plans [Member] \| Duke Energy Florida [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	61	39
Accumulated benefit obligation	61	39
Non-Qualified Pension Plans [Member] \| Duke Energy Ohio [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	4	3
Accumulated benefit obligation	4	3
Non-Qualified Pension Plans [Member] \| Duke Energy Indiana [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	5	5
Accumulated benefit obligation	$ 5	$ 5

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If aggregate disclosures are presented, the aggregate pension accumulated benefit obligation for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 55

-Paragraph 17

-URI http://asc.fasb.org/extlink&oid=34716465&loc=d3e4179-114921

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e2417-114920

+ Details

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- Definition

If aggregate disclosures are presented, the aggregate fair value of plan assets for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References

+ Details

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- Definition

If aggregate disclosures are presented, the aggregate projected benefit obligation for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References

+ Details

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