v2.4.0.6

Severance (Narrative)(Details) (USD $) In Millions, unless otherwise specified | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2013 2011 Severance Plan [Member] | Mar. 31, 2012 2011 Severance Plan [Member] Employees | Mar. 31, 2013 Duke Energy Ohio Union 2012 Severance Plan [Member] Employees | Mar. 31, 2013 Crystal River Unit 3 2013 Severance Plan [Member] | Dec. 31, 2014 Crystal River Unit 3 2013 Severance Plan [Member] Employees
Restructuring Cost and Reserve [Line Items] |  |  |  |  |
Number of employees that accepted the termination benefits |  | 1,100 | 75 |  |
Number of eligible employees |  |  |  |  | 600
Estimated severance expense | $ 20 |  |  |  |
Deferred severance costs |  |  |  | $ 16 |

X
- Definition The deferral in the period for known and estimated costs of termination benefits provided to current employees that are involuntarily terminated under a benefit arrangement associated with exit from or disposal of business activities or restructurings pursuant to a duly authorized plan, excluding costs or losses pertaining to an entity newly acquired in a business combination or a discontinued operation as defined by generally accepted accounting principles and costs associated with one-time termination benefits. + References No definition available. + Details
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Namespace Prefix: | duk_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition An estimate of the change against earnings in future periods for known and estimated costs of termination benefits provided to current employees that are involuntarily terminated under a benefit arrangement associated with exit from or disposal of business activities or restructurings pursuant to a duly authorized plan, excluding costs or losses pertaining to an entity newly acquired in a business combination or a discontinued operation as defined by generally accepted accounting principles and costs associated with one-time termination benefits. + References No definition available. + Details
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Namespace Prefix: | duk_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of eligible employees + References No definition available. + Details
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Namespace Prefix: | duk_
Data Type: | xbrli:positiveIntegerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of employees accepted the Voluntary program + References No definition available. + Details
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Namespace Prefix: | duk_
Data Type: | xbrli:positiveIntegerItemType
Balance Type: | na
Period Type: | duration

X
- Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration