Dispositions (Plants in Disposal Group) (Details) (Duke Energy Ohio [Member])	3 Months Ended
	Mar. 31, 2014 MW
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant capacity, MW	9,469	[1]
Owned Plant capacity, MW	6,090	[1]
Miami Fort Units 7 and 8 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant capacity, MW	1,020	[1],[2]
Owned Plant capacity, MW	653	[1],[2]
Ownership share	64.00%	[2]
Stuart [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant capacity, MW	2,318	[1],[2],[3]
Owned Plant capacity, MW	904	[1],[2],[3]
Ownership share	39.00%	[2],[3]
Conesville [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant capacity, MW	780	[1],[2],[3]
Owned Plant capacity, MW	312	[1],[2],[3]
Ownership share	40.00%	[2],[3]
Zimmer [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant capacity, MW	1,338	[1],[2]
Owned Plant capacity, MW	622	[1],[2]
Ownership share	46.50%	[2]
Killen [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant capacity, MW	618	[1],[2],[3]
Owned Plant capacity, MW	204	[1],[2],[3]
Ownership share	33.00%	[2],[3]
Hanging Rock [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant capacity, MW	1,274	[1]
Owned Plant capacity, MW	1,274	[1]
Ownership share	100.00%
Washington [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant capacity, MW	637	[1]
Owned Plant capacity, MW	637	[1]
Ownership share	100.00%
Fayette [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant capacity, MW	640	[1]
Owned Plant capacity, MW	640	[1]
Ownership share	100.00%
Lee [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant capacity, MW	640	[1]
Owned Plant capacity, MW	640	[1]
Ownership share	100.00%
Dicks Creek [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant capacity, MW	136	[1]
Owned Plant capacity, MW	136	[1]
Ownership share	100.00%
Miami Fort [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant capacity, MW	68	[1]
Owned Plant capacity, MW	68	[1]
Ownership share	100.00%

[1] Average MW capacity is calculated as the average of winter capacity and summer capacity.

[2] Jointly owned with Ohio Power Company and/or The Dayton Power & Light Company.

[3] Station is not operated by Duke Energy Ohio.