Stock-Based Compensation (Schedule of Stock-Based Compensation Expense) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	$ 38	$ 38	$ 52
Pretax stock-based compensation expense	61	61	85
Tax benefit associated with stock-based compensation expense	23	23	33
Stock-based compensation costs capitalized	3	4	3
Restricted Stock Units Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pretax stock-based compensation expense	38	39	49
Performance Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pretax stock-based compensation expense	23	22	34
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pretax stock-based compensation expense			2
Duke Energy Carolinas [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	14	12	13
Progress Energy [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	14	14	23
Duke Energy Progress [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	9	9	14
Duke Energy Florida [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	5	5	9
Duke Energy Ohio [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	2	5	4
Duke Energy Indiana [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	$ 4	$ 3	$ 4

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 14.F)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 14
-Section F

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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-Paragraph 2
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