Derivatives and Hedging (Schedule of Offsetting Assets and Liabilities: Derivatives and Collateral Posted) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Derivative Assets
Gross amounts recognized	$ 797	$ 461
Net amounts recognized on the Condensed Consolidated Balance Sheet	133	145
Derivative Liabilities
Gross amounts recognized	1,171	636
Net amounts recognized on the Condensed Consolidated Balance Sheet	507	321
Other Current Assets [Member]
Derivative Assets
Gross amounts recognized	506	214
Gross amounts offset	(504)	(179)
Net amount subject to master netting	2	35
Amounts not subject to master netting
Net amounts recognized on the Condensed Consolidated Balance Sheet	2	35
Other Noncurrent Assets [Member]
Derivative Assets
Gross amounts recognized	282	233
Gross amounts offset	(277)	(138)
Net amount subject to master netting	5	95
Amounts not subject to master netting	9	14
Net amounts recognized on the Condensed Consolidated Balance Sheet	14	109
Other Current Liabilities [Member]
Derivative Liabilities
Gross amounts recognized	715	322
Gross amounts offset	(576)	(192)
Net amount subject to master netting	139	130
Amounts not subject to master netting	6	4
Net amounts recognized on the Condensed Consolidated Balance Sheet	145	134
Other Noncurrent Liabilities [Member]
Derivative Liabilities
Gross amounts recognized	442	299
Gross amounts offset	(366)	(155)
Net amount subject to master netting	76	144
Amounts not subject to master netting	8	11
Net amounts recognized on the Condensed Consolidated Balance Sheet	84	155
Progress Energy [Member]
Derivative Assets
Gross amounts recognized	28	20
Net amounts recognized on the Condensed Consolidated Balance Sheet	3	3
Derivative Liabilities
Gross amounts recognized	172	204
Net amounts recognized on the Condensed Consolidated Balance Sheet	147	187
Progress Energy [Member] | Other Current Assets [Member]
Derivative Assets
Gross amounts recognized	21	15
Gross amounts offset	(20)	(13)
Net amount subject to master netting		2
Amounts not subject to master netting
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	2
Progress Energy [Member] | Other Noncurrent Assets [Member]
Derivative Assets
Gross amounts recognized	7	5
Gross amounts offset	(5)	(4)
Net amount subject to master netting		1
Amounts not subject to master netting
Net amounts recognized on the Condensed Consolidated Balance Sheet	2	1
Progress Energy [Member] | Other Current Liabilities [Member]
Derivative Liabilities
Gross amounts recognized	125	107
Gross amounts offset	(21)	(17)
Net amount subject to master netting		90
Amounts not subject to master netting
Net amounts recognized on the Condensed Consolidated Balance Sheet	104	90
Progress Energy [Member] | Other Noncurrent Liabilities [Member]
Derivative Liabilities
Gross amounts recognized	47	93
Gross amounts offset	(6)	(10)
Net amount subject to master netting		83
Amounts not subject to master netting		4
Net amounts recognized on the Condensed Consolidated Balance Sheet	41	87
Duke Energy Progress [Member]
Derivative Assets
Gross amounts recognized	13	6
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	1
Derivative Liabilities
Gross amounts recognized	74	71
Net amounts recognized on the Condensed Consolidated Balance Sheet	62	66
Duke Energy Progress [Member] | Other Current Assets [Member]
Derivative Assets
Gross amounts recognized	11	3
Gross amounts offset	(11)	(3)
Net amounts recognized on the Condensed Consolidated Balance Sheet
Duke Energy Progress [Member] | Other Noncurrent Assets [Member]
Derivative Assets
Gross amounts recognized	2	3
Gross amounts offset	(1)	(3)
Net amounts recognized on the Condensed Consolidated Balance Sheet	1
Duke Energy Progress [Member] | Other Current Liabilities [Member]
Derivative Liabilities
Gross amounts recognized	57	41
Gross amounts offset	(11)	(3)
Net amounts recognized on the Condensed Consolidated Balance Sheet	46	38
Duke Energy Progress [Member] | Other Noncurrent Liabilities [Member]
Derivative Liabilities
Gross amounts recognized	17	30
Gross amounts offset	(1)	(3)
Net amounts recognized on the Condensed Consolidated Balance Sheet	16	27
Duke Energy Florida [Member]
Derivative Assets
Gross amounts recognized	15	14
Net amounts recognized on the Condensed Consolidated Balance Sheet	2	1
Derivative Liabilities
Gross amounts recognized	98	129
Net amounts recognized on the Condensed Consolidated Balance Sheet	85	116
Duke Energy Florida [Member] | Other Current Assets [Member]
Derivative Assets
Gross amounts recognized	10	12
Gross amounts offset	(9)	(10)
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	2
Duke Energy Florida [Member] | Other Noncurrent Assets [Member]
Derivative Assets
Gross amounts recognized	5	2
Gross amounts offset	(4)	(2)
Net amounts recognized on the Condensed Consolidated Balance Sheet	1
Duke Energy Florida [Member] | Other Current Liabilities [Member]
Derivative Liabilities
Gross amounts recognized	68	66
Gross amounts offset	(10)	(15)
Net amounts recognized on the Condensed Consolidated Balance Sheet	58	51
Duke Energy Florida [Member] | Other Noncurrent Liabilities [Member]
Derivative Liabilities
Gross amounts recognized	30	63
Gross amounts offset	(5)	(7)
Net amounts recognized on the Condensed Consolidated Balance Sheet	25	56
Duke Energy Ohio [Member]
Derivative Assets
Gross amounts recognized	841	391
Net amounts recognized on the Condensed Consolidated Balance Sheet	18	96
Derivative Liabilities
Gross amounts recognized	1,117	390
Net amounts recognized on the Condensed Consolidated Balance Sheet	294	95
Duke Energy Ohio [Member] | Other Current Assets [Member]
Derivative Assets
Gross amounts recognized	513	186
Gross amounts offset	(504)	(165)
Net amount subject to master netting		21
Amounts not subject to master netting
Net amounts recognized on the Condensed Consolidated Balance Sheet	9	21
Duke Energy Ohio [Member] | Other Noncurrent Assets [Member]
Derivative Assets
Gross amounts recognized	328	205
Gross amounts offset	(322)	(132)
Net amount subject to master netting		73
Amounts not subject to master netting
Net amounts recognized on the Condensed Consolidated Balance Sheet	6	73
Duke Energy Ohio [Member] | Other Current Liabilities [Member]
Derivative Liabilities
Gross amounts recognized	637	199
Gross amounts offset	(574)	(173)
Net amount subject to master netting		26
Amounts not subject to master netting		1
Net amounts recognized on the Condensed Consolidated Balance Sheet	63	27
Duke Energy Ohio [Member] | Other Noncurrent Liabilities [Member]
Derivative Liabilities
Gross amounts recognized	480	186
Gross amounts offset	(410)	(143)
Net amount subject to master netting		43
Amounts not subject to master netting		4
Net amounts recognized on the Condensed Consolidated Balance Sheet	$ 70	$ 47