Variable Interest Entities (Fair Value Assumptions)(Details) - Variable Interest Entity, Not Primary Beneficiary [Member] - Cinergy Receivables [Member]	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016
Duke Energy Ohio [Member]
Variable Interest Entities [Line Items]
Anticipated credit loss ratio	0.50%	0.50%
Discount rate	2.00%	1.50%
Receivable turnover rate	13.40%	13.30%
Duke Energy Indiana [Member]
Variable Interest Entities [Line Items]
Anticipated credit loss ratio	0.30%	0.30%
Discount rate	2.00%	1.50%
Receivable turnover rate	10.70%	10.60%

The ratio of total receivables to total monthly billings, as related to total receivables.

No definition available.

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- Definition

Discount rate which is used to value residual cash flows generated by financial assets of a securitization, asset-backed financing arrangement, or similar transfer regardless of when the transfer occurred.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=82924980&loc=d3e107314-111719

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	na
Period Type:	duration

- Definition

Rate at which principal will not be repaid on securitized financial assets regardless of when the transfer occurred.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=82924980&loc=d3e107314-111719

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Details

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- Details

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- Details

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- Details

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