Derivatives and Hedging (Schedule of Offsetting Assets and Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	$ 411	$ 351
Net amounts recognized on the Condensed Consolidated Balance Sheet	52us-gaap_DerivativeAssets	110us-gaap_DerivativeAssets
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	984	909
Net amounts recognized on the Condensed Consolidated Balance Sheet	625us-gaap_DerivativeLiabilities	668us-gaap_DerivativeLiabilities
Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	261	210
Gross amounts offset	(227)	(153)
Net amount subject to master netting	34	57
Net amounts recognized on the Condensed Consolidated Balance Sheet	34	57
Investments And Other Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	150	136
Gross amounts offset	(131)	(88)
Net amount subject to master netting	19	48
Amounts not subject to master netting		5
Net amounts recognized on the Condensed Consolidated Balance Sheet	19	53
Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	607	573
Gross amounts offset	(293)	(213)
Net amounts subject to master netting	314	360
Amounts not subject to master netting		1
Net amounts recognized on the Condensed Consolidated Balance Sheet	314	361
Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	377	319
Gross amounts offset	(216)	(173)
Net amounts subject to master netting	161	146
Amounts not subject to master netting		16
Net amounts recognized on the Condensed Consolidated Balance Sheet	161	162
Duke Energy Carolinas [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	27	19
Net amounts recognized on the Condensed Consolidated Balance Sheet	27	19
Duke Energy Carolinas [Member] \| Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	19	14
Net amounts subject to master netting	19	14
Net amounts recognized on the Condensed Consolidated Balance Sheet	19	14
Duke Energy Carolinas [Member] \| Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	8	5
Net amounts subject to master netting	8	5
Net amounts recognized on the Condensed Consolidated Balance Sheet	8	5
Progress Energy [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	9	2
Net amounts recognized on the Condensed Consolidated Balance Sheet	6	4
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	398	371
Net amounts recognized on the Condensed Consolidated Balance Sheet	395	373
Progress Energy [Member] \| Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	6	2
Gross amounts offset	(1)	(2)
Net amount subject to master netting	5
Net amounts recognized on the Condensed Consolidated Balance Sheet	5
Progress Energy [Member] \| Investments And Other Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	3
Gross amounts offset	(2)
Net amount subject to master netting	1
Net amounts recognized on the Condensed Consolidated Balance Sheet	1
Progress Energy [Member] \| Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	289	289
Gross amounts offset	(32)	(17)
Net amounts subject to master netting	257	272
Net amounts recognized on the Condensed Consolidated Balance Sheet	257	272
Progress Energy [Member] \| Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	109	82
Gross amounts offset	(14)	(8)
Net amounts subject to master netting	95	74
Net amounts recognized on the Condensed Consolidated Balance Sheet	95	74
Duke Energy Progress [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	2
Net amounts recognized on the Condensed Consolidated Balance Sheet	2
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	131	132
Net amounts recognized on the Condensed Consolidated Balance Sheet	131	132
Duke Energy Progress [Member] \| Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	2
Net amount subject to master netting	2
Net amounts recognized on the Condensed Consolidated Balance Sheet	2
Duke Energy Progress [Member] \| Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	100	109
Gross amounts offset	(1)
Net amounts subject to master netting	99	109
Net amounts recognized on the Condensed Consolidated Balance Sheet	99	109
Duke Energy Progress [Member] \| Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	31	23
Net amounts subject to master netting	31	23
Net amounts recognized on the Condensed Consolidated Balance Sheet	31	23
Duke Energy Florida [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	7	2
Net amounts recognized on the Condensed Consolidated Balance Sheet	4	4
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	267	239
Net amounts recognized on the Condensed Consolidated Balance Sheet	264	241
Duke Energy Florida [Member] \| Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	4	2
Gross amounts offset	(1)	(2)
Net amount subject to master netting	3
Net amounts recognized on the Condensed Consolidated Balance Sheet	3
Duke Energy Florida [Member] \| Investments And Other Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	3
Gross amounts offset	(2)
Net amount subject to master netting	1
Net amounts recognized on the Condensed Consolidated Balance Sheet	1
Duke Energy Florida [Member] \| Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	189	180
Gross amounts offset	(31)	(17)
Net amounts subject to master netting	158	163
Net amounts recognized on the Condensed Consolidated Balance Sheet	158	163
Duke Energy Florida [Member] \| Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	78	59
Gross amounts offset	(14)	(8)
Net amounts subject to master netting	64	51
Net amounts recognized on the Condensed Consolidated Balance Sheet	64	51
Duke Energy Ohio [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	455	341
Net amounts recognized on the Condensed Consolidated Balance Sheet	44	49
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	545	473
Net amounts recognized on the Condensed Consolidated Balance Sheet	134	181
Duke Energy Ohio [Member] \| Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	284	204
Gross amounts offset	(265)	(179)
Net amount subject to master netting	19	25
Net amounts recognized on the Condensed Consolidated Balance Sheet	19	25
Duke Energy Ohio [Member] \| Investments And Other Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	171	137
Gross amounts offset	(145)	(114)
Net amount subject to master netting	26	23
Net amounts recognized on the Condensed Consolidated Balance Sheet	26	23
Duke Energy Ohio [Member] \| Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	309	257
Gross amounts offset	(300)	(222)
Net amounts subject to master netting	9	35
Net amounts recognized on the Condensed Consolidated Balance Sheet	9	35
Duke Energy Ohio [Member] \| Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	236	216
Gross amounts offset	(218)	(193)
Net amounts subject to master netting	18	23
Net amounts recognized on the Condensed Consolidated Balance Sheet	18	23
Duke Energy Indiana [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	3	14
Net amounts recognized on the Condensed Consolidated Balance Sheet	3	14
Duke Energy Indiana [Member] \| Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	3	14
Net amount subject to master netting	3	14
Net amounts recognized on the Condensed Consolidated Balance Sheet	$ 3	$ 14

Fair value of liability associated with financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset.

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