Regulatory Matters (Schedule of MISO Exit fees)(Details) (Duke Energy Ohio [Member], RTO Realignment [Member], USD $) In Millions, unless otherwise specified	6 Months Ended
Jun. 30, 2014
Duke Energy Ohio [Member] \| RTO Realignment [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period	$ 95
Provision / Adjustments	1
Cash Reductions	(2)
Balance, end of period	$ 94

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

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-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

-Section 45

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Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

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

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-SubTopic 10

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Amount of any reversal and other adjustment made during the period to the amount of a previously accrued liability for a specified type of restructuring cost, excluding adjustments for costs incurred during the period, costs settled during the period, and foreign currency translation adjustments.

+ References

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

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