Goodwill and Intangible Assets (Goodwill By Reportable Operating Segment) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Goodwill [Line Items]
Goodwill	$ 17,192us-gaap_GoodwillGross	$ 17,211us-gaap_GoodwillGross
Accumulated impairment charges	(871)	(871)
Goodwill as adjusted for accumulated impairment charges	16,321us-gaap_Goodwill	16,340us-gaap_Goodwill
Foreign exchange and other changes	(19)
Regulated Utilities [Member]
Goodwill [Line Items]
Goodwill	15,950	15,950
Goodwill as adjusted for accumulated impairment charges	15,950	15,950
Commercial Power [Member]
Goodwill [Line Items]
Goodwill	935	935
Accumulated impairment charges	(871)	(871)
Goodwill as adjusted for accumulated impairment charges	64	64
International [Member]
Goodwill [Line Items]
Goodwill	307	326
Goodwill as adjusted for accumulated impairment charges	307	326
Foreign exchange and other changes	(19)
Progress Energy [Member]
Goodwill [Line Items]
Goodwill as adjusted for accumulated impairment charges	3,655	3,655
Duke Energy Ohio [Member]
Goodwill [Line Items]
Goodwill	2,324	2,324
Accumulated impairment charges	(1,404)	(1,404)
Goodwill as adjusted for accumulated impairment charges	920	920
Duke Energy Ohio [Member] \| Regulated Utilities [Member]
Goodwill [Line Items]
Goodwill	1,136	1,136
Accumulated impairment charges	(216)	(216)
Goodwill as adjusted for accumulated impairment charges	920	920
Duke Energy Ohio [Member] \| DEO Commercial Power [Member]
Goodwill [Line Items]
Goodwill	1,188	1,188
Accumulated impairment charges	$ (1,188)	$ (1,188)

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

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Amount before accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (a,h)

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

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Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase (decrease) from foreign currency translation adjustments and purchase accounting adjustments of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

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