Derivatives and Hedging (Schedule of Offsetting Assets and Liabilities: Derivatives and Collateral Posted) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Derivative Assets Subject to Master Netting
Gross amounts recognized	$ 803		$ 461
Net amounts recognized on the Condensed Consolidated Balance Sheet	125		145
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	1,012		636
Net amounts recognized on the Condensed Consolidated Balance Sheet	334		321
Other Current Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	454		214
Gross amounts offset	(436)		(179)
Net amount subject to master netting	18		35
Net amounts recognized on the Condensed Consolidated Balance Sheet	18	[1]	35	[1]
Other Noncurrent Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	338		233
Gross amounts offset	(265)		(138)
Net amount subject to master netting	73		95
Amounts not subject to master netting	11		14
Net amounts recognized on the Condensed Consolidated Balance Sheet	84	[2]	109	[2]
Other Current Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	606		322
Gross amounts offset	(473)		(192)
Net amount subject to master netting	133		130
Amounts not subject to master netting	1		4
Net amounts recognized on the Condensed Consolidated Balance Sheet	134	[3]	134	[3]
Other Noncurrent Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	399		299
Gross amounts offset	(267)		(155)
Net amount subject to master netting	132		144
Amounts not subject to master netting	6		11
Net amounts recognized on the Condensed Consolidated Balance Sheet	138	[4]	155	[4]
Duke Energy Carolinas [Member]
Derivative Liabilities Subject to Master Netting
Net amounts recognized on the Condensed Consolidated Balance Sheet	4		(2)
Progress Energy [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	36		20
Net amounts recognized on the Condensed Consolidated Balance Sheet	4		3
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	190		204
Net amounts recognized on the Condensed Consolidated Balance Sheet	158		187
Progress Energy [Member] | Other Current Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	32		15
Gross amounts offset	(28)		(13)
Net amount subject to master netting			2
Net amounts recognized on the Condensed Consolidated Balance Sheet	4	[5]	2	[5]
Progress Energy [Member] | Other Noncurrent Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	4		5
Gross amounts offset	(4)		(4)
Net amount subject to master netting			1
Net amounts recognized on the Condensed Consolidated Balance Sheet			1	[6]
Progress Energy [Member] | Other Current Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	108		107
Gross amounts offset	(34)		(17)
Net amount subject to master netting			90
Net amounts recognized on the Condensed Consolidated Balance Sheet	74	[7]	90	[7]
Progress Energy [Member] | Other Noncurrent Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	82		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	76	[8]	87	[8]
Duke Energy Progress [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	15		6
Net amounts recognized on the Condensed Consolidated Balance Sheet	1		1
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	72		71
Net amounts recognized on the Condensed Consolidated Balance Sheet	58		66
Duke Energy Progress [Member] | Other Current Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	13		3
Gross amounts offset	(11)		(3)
Net amounts recognized on the Condensed Consolidated Balance Sheet	2
Duke Energy Progress [Member] | Other Noncurrent Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	2		3
Gross amounts offset	(2)		(3)
Duke Energy Progress [Member] | Other Current Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	48		41
Gross amounts offset	(11)		(3)
Net amounts recognized on the Condensed Consolidated Balance Sheet	37	[7]	38	[7]
Duke Energy Progress [Member] | Other Noncurrent Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	24		30
Gross amounts offset	(2)		(3)
Net amounts recognized on the Condensed Consolidated Balance Sheet	22	[8]	27	[8]
Duke Energy Florida [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	21		14
Net amounts recognized on the Condensed Consolidated Balance Sheet	3		1
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	117		129
Net amounts recognized on the Condensed Consolidated Balance Sheet	99		116
Duke Energy Florida [Member] | Other Current Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	19		12
Gross amounts offset	(16)		(10)
Net amounts recognized on the Condensed Consolidated Balance Sheet	3	[9]	2	[9]
Duke Energy Florida [Member] | Other Noncurrent Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	2		2
Gross amounts offset	(2)		(2)
Duke Energy Florida [Member] | Other Current Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	59		66
Gross amounts offset	(20)		(15)
Net amounts recognized on the Condensed Consolidated Balance Sheet	39	[10]	51	[10]
Duke Energy Florida [Member] | Other Noncurrent Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	58		63
Gross amounts offset	(6)		(7)
Net amounts recognized on the Condensed Consolidated Balance Sheet	52	[11]	56	[11]
Duke Energy Ohio [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	732		391
Net amounts recognized on the Condensed Consolidated Balance Sheet	63		96
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	778		390
Net amounts recognized on the Condensed Consolidated Balance Sheet	113		95
Duke Energy Ohio [Member] | Other Current Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	413		186
Gross amounts offset	(407)		(165)
Net amount subject to master netting			21
Net amounts recognized on the Condensed Consolidated Balance Sheet	6	[12]	21	[12]
Duke Energy Ohio [Member] | Other Noncurrent Assets [Member]
Derivative Assets Subject to Master Netting
Gross amounts recognized	319		205
Gross amounts offset	(260)		(132)
Net amount subject to master netting			73
Net amounts recognized on the Condensed Consolidated Balance Sheet	59	[13]	73	[13]
Duke Energy Ohio [Member] | Other Current Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	482		199
Gross amounts offset	(438)		(173)
Net amount subject to master netting			26
Amounts not subject to master netting			1
Net amounts recognized on the Condensed Consolidated Balance Sheet	44	[14]	27	[14]
Duke Energy Ohio [Member] | Other Noncurrent Liabilities [Member]
Derivative Liabilities Subject to Master Netting
Gross amounts recognized	296		186
Gross amounts offset	(260)		(143)
Net amount subject to master netting			43
Amounts not subject to master netting			4
Net amounts recognized on the Condensed Consolidated Balance Sheet	36	[15]	47	[15]
Duke Energy Indiana [Member]
Derivative Assets Subject to Master Netting
Net amounts recognized on the Condensed Consolidated Balance Sheet	$ 8		$ 12

[1] Included in Other and Assets Held for Sale within Current Assets on the Condensed Consolidated Balance Sheet.

[2] Included in Other and Assets Held for Sale within Investments and Other Assets on the Condensed Consolidated Balance Sheet.

[3] Included in Other and Liabilities Associated with Assets Held for Sale within Current Liabilities on the Condensed Consolidated Balance Sheet.

[4] Included in Other and Liabilities Associated with Assets Held for Sale within Deferred Credits and Other Liabilities on the Condensed Consolidated Balance Sheet.

[5] Included in Other within Current Assets on the Condensed Consolidated Balance Sheet.

[6] Included in Other within Investments and Other Assets on the Condensed Consolidated Balance Sheet.

[7] Included in Other within Current Liabilities on the Condensed Consolidated Balance Sheet.

[8] Included in Other within Deferred Credits and Other Liabilities on the Condensed Consolidated Balance Sheet.

[9] Included in Other within Current Assets on the Condensed Balance Sheet.

[10] Included in Other within Current Liabilities on the Condensed Balance Sheet.

[11] Included in Other within Deferred Credits and Other Liabilities on the Condensed Balance Sheet.

[12] Included in Assets Held for Sale within Current Assets on the Condensed Consolidated Balance Sheet.

[13] Included in Assets Held for Sale within Investments and Other Assets on the Condensed Consolidated Balance Sheet.

[14] Included in Liabilities Associated with Assets Held for Sale within Current Liabilities on the Condensed Consolidated Balance Sheet.

[15] Included in Liabilities Associated with Assets Held for Sale within Deferred Credits and Other Liabilities on the Condensed Consolidated Balance Sheet.