Derivatives and Hedging (Schedule of Offsetting Assets and Liabilities: Derivatives and Collateral Posted) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Derivative Assets Subject to Master Netting
Gross amounts recognized	$ 461	$ 264
Net amounts recognized on the Condensed Consolidated Balance Sheet	145	103
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	636	917
Net amounts recognized on the Condensed Consolidated Balance Sheet	321	756
Other Current Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	214	127
Gross amounts offset	(179)	(114)
Net amount subject to master netting	35	13
Amounts not subject to master netting		22
Net amounts recognized on the Condensed Consolidated Balance Sheet	35	35
Other Noncurrent Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	233	96
Gross amounts offset	(138)	(54)
Net amount subject to master netting	95	42
Amounts not subject to master netting	14	19
Net amounts recognized on the Condensed Consolidated Balance Sheet	109	61
Other Current Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	322	402
Gross amounts offset	(192)	(151)
Net amount subject to master netting	130	251
Amounts not subject to master netting	4	166
Net amounts recognized on the Condensed Consolidated Balance Sheet	134	417
Other Noncurrent Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	299	295
Gross amounts offset	(155)	(90)
Net amount subject to master netting	144	205
Amounts not subject to master netting	11	54
Net amounts recognized on the Condensed Consolidated Balance Sheet	155	259
Duke Energy Carolinas [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	2	12
Net amounts recognized on the Condensed Consolidated Balance Sheet	2	12
Duke Energy Carolinas [Member] | Other Current Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Amounts not subject to master netting	1	6
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	6
Duke Energy Carolinas [Member] | Other Noncurrent Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Amounts not subject to master netting	1	6
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	6
Progress Energy [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	20	11
Net amounts recognized on the Condensed Consolidated Balance Sheet	3	11
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	204	440
Net amounts recognized on the Condensed Consolidated Balance Sheet	187	440
Progress Energy [Member] | Other Current Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	15	3
Gross amounts offset	(13)
Net amount subject to master netting	2	3
Net amounts recognized on the Condensed Consolidated Balance Sheet	2	3
Progress Energy [Member] | Other Noncurrent Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	5	8
Gross amounts offset	(4)
Net amount subject to master netting	1	8
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	8
Progress Energy [Member] | Other Current Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	107	244
Gross amounts offset	(17)	(22)
Net amount subject to master netting	90	222
Net amounts recognized on the Condensed Consolidated Balance Sheet	90	222
Progress Energy [Member] | Other Noncurrent Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	93	192
Gross amounts offset	(10)	(36)
Net amount subject to master netting	83	156
Amounts not subject to master netting	4	4
Net amounts recognized on the Condensed Consolidated Balance Sheet	87	160
Duke Energy Progress [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	6	2
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	2
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	71	166
Net amounts recognized on the Condensed Consolidated Balance Sheet	66	166
Duke Energy Progress [Member] | Other Current Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	3	1
Gross amounts offset	(3)
Net amount subject to master netting		1
Net amounts recognized on the Condensed Consolidated Balance Sheet		1
Duke Energy Progress [Member] | Other Noncurrent Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	3	1
Gross amounts offset	(3)
Net amount subject to master netting		1
Net amounts recognized on the Condensed Consolidated Balance Sheet		1
Duke Energy Progress [Member] | Other Current Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	41	97
Gross amounts offset	(3)	(2)
Net amount subject to master netting	38	95
Net amounts recognized on the Condensed Consolidated Balance Sheet	38	95
Duke Energy Progress [Member] | Other Noncurrent Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	30	69
Gross amounts offset	(3)	(7)
Net amount subject to master netting	27	62
Net amounts recognized on the Condensed Consolidated Balance Sheet	27	62
Duke Energy Florida [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	14	9
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	9
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	129	270
Net amounts recognized on the Condensed Consolidated Balance Sheet	116	270
Duke Energy Florida [Member] | Other Current Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	12	2
Gross amounts offset	(10)
Net amount subject to master netting	2	2
Net amounts recognized on the Condensed Consolidated Balance Sheet	2	2
Duke Energy Florida [Member] | Other Noncurrent Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	2	7
Gross amounts offset	(2)
Net amount subject to master netting		7
Net amounts recognized on the Condensed Consolidated Balance Sheet		7
Duke Energy Florida [Member] | Other Current Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	66	147
Gross amounts offset	(15)	(20)
Net amount subject to master netting	51	127
Net amounts recognized on the Condensed Consolidated Balance Sheet	51	127
Duke Energy Florida [Member] | Other Noncurrent Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	63	123
Gross amounts offset	(7)	(29)
Net amount subject to master netting	56	94
Net amounts recognized on the Condensed Consolidated Balance Sheet	56	94
Duke Energy Ohio [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	391	220
Net amounts recognized on the Condensed Consolidated Balance Sheet	96	59
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	390	199
Net amounts recognized on the Condensed Consolidated Balance Sheet	95	38
Duke Energy Ohio [Member] | Other Current Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	186	137
Gross amounts offset	(165)	(110)
Net amount subject to master netting	21	27
Amounts not subject to master netting		2
Net amounts recognized on the Condensed Consolidated Balance Sheet	21	29
Duke Energy Ohio [Member] | Other Noncurrent Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	205	81
Gross amounts offset	(132)	(51)
Net amount subject to master netting	73	30
Net amounts recognized on the Condensed Consolidated Balance Sheet	73	30
Duke Energy Ohio [Member] | Other Current Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	199	136
Gross amounts offset	(173)	(125)
Net amount subject to master netting	26	11
Amounts not subject to master netting	1	1
Net amounts recognized on the Condensed Consolidated Balance Sheet	27	12
Duke Energy Ohio [Member] | Other Noncurrent Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	186	55
Gross amounts offset	(143)	(51)
Net amount subject to master netting	43	4
Amounts not subject to master netting	4	7
Net amounts recognized on the Condensed Consolidated Balance Sheet	47	11
Duke Energy Indiana [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	12	10
Net amounts recognized on the Condensed Consolidated Balance Sheet	12	10
Derivative Liabilities Subject to Master Netting
Gross amounts recognized		63
Net amounts recognized on the Condensed Consolidated Balance Sheet		63
Duke Energy Indiana [Member] | Other Current Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	12
Gross amounts offset	(1)
Net amount subject to master netting	11
Amounts not subject to master netting		10
Net amounts recognized on the Condensed Consolidated Balance Sheet	11	10
Duke Energy Indiana [Member] | Other Current Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Amounts not subject to master netting		63
Net amounts recognized on the Condensed Consolidated Balance Sheet		$ 63