Organization And Basis Of Presentation (Schedule Of Unbilled Revenues With Restricted Receivables) (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended	3 Months Ended										12 Months Ended
	Jul. 02, 2012	Dec. 31, 2012		Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011		Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2009
Stockholders' Equity Note [Abstract]
Stockholders' Equity Note, Stock Split, Conversion Ratio	0.333
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents		$ 1,424					$ 2,110					$ 1,424		$ 2,110		$ 1,670	$ 1,542
Restricted Cash [Abstract]
Restricted Cash		574					104					574		104
Energy Related Inventory [Abstract]
Materials and supplies		1,751					873					1,751		873
Coal held for electric generation		1,468					712					1,468		712
Natural gas		4					3					4		3
Inventory, Net, Total		3,223					1,588					3,223		1,588
Depreciation Rate [Abstract]
Weighted-average depreciation rate												2.90%		3.20%		3.20%
Unbilled Receivables [Abstract]
Unbilled Receivables, Current		920					674					920		674
Allowance For Doubtful Accounts [Abstract]
Receivables, allowance for doubtful accounts		34					35					34		35		34
Restricted receivables, allowance for doubtful accounts		44					40					44		40		34
Assets and Liabilities, Current [Abstract]
Collateral Already Posted, Aggregate Fair Value		163					36					163		36
Employee-related Liabilities, Current		725					407					725		407
Derivative, Collateral, Obligation to Return Cash		93					30					93		30
Income Amounts Attributable to Parent, Disclosures [Abstract]
Income (Loss) from Continuing Operations Attributable to Parent												1,732		1,705		1,317
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent												36		1		3
Net Income Attributable to Duke Energy Corporation		435		594	444	295	288		472	435	511	1,768		1,706		1,320
Excise Taxes [Abstract]
Excise taxes												466		293		300
Foreign Jurisdictions [Member]
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents		731										731
Duke Energy Carolinas [Member]
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents		19					289					19		289		153	394
Energy Related Inventory [Abstract]
Materials and supplies		574					505					574		505
Coal held for electric generation		488					412					488		412
Inventory, Net, Total		1,062					917					1,062		917
Depreciation Rate [Abstract]
Weighted-average depreciation rate												2.80%		2.60%		2.70%
Unbilled Receivables [Abstract]
Unbilled Receivables, Current		315					293					315		293
Allowance For Doubtful Accounts [Abstract]
Receivables, allowance for doubtful accounts		3					3					3		3		3
Restricted receivables, allowance for doubtful accounts		6					6					6		6		6
Assets and Liabilities, Current [Abstract]
Employee-related Liabilities, Current		203					163					203		163
Derivative, Collateral, Obligation to Return Cash		105	[1]				94	[1]				105	[1]	94	[1]
Excise Taxes [Abstract]
Excise taxes												161		153		156
Progress Energy [Member]
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents		231					230					231		230		611	725
Restricted Cash [Abstract]
Restricted Cash		11					35					11		35
Energy Related Inventory [Abstract]
Materials and supplies		768					747					768		747
Coal held for electric generation		673					681					673		681
Natural gas							1							1
Inventory, Net, Total		1,441					1,429					1,441		1,429
Depreciation Rate [Abstract]
Weighted-average depreciation rate												2.60%		2.30%		2.00%
Unbilled Receivables [Abstract]
Unbilled Receivables, Current		187					157					187		157
Allowance For Doubtful Accounts [Abstract]
Receivables, allowance for doubtful accounts		16					27					16		27		35
Assets and Liabilities, Current [Abstract]
Collateral Already Posted, Aggregate Fair Value		59					147					59		147
Employee-related Liabilities, Current		304	[1]				155	[1]				304	[1]	155	[1]
Derivative, Collateral, Obligation to Return Cash		1					3					1		3
Customer Deposits, Current		342					340					342		340
Derivative Liabilities, Current		221					382					221		382
Income Amounts Attributable to Parent, Disclosures [Abstract]
Income (Loss) from Continuing Operations Attributable to Parent												348		580		860
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent												52		(5)		(4)
Net Income Attributable to Duke Energy Corporation		32		155	63	150	(76)		291	176	184	400		575		856
Excise Taxes [Abstract]
Excise taxes												317		315		345
Progress Energy Carolinas [Member]
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents		18					20					18		20		230	35
Energy Related Inventory [Abstract]
Materials and supplies		499					446					499		446
Coal held for electric generation		329					323					329		323
Natural gas							1							1
Inventory, Net, Total		828					770					828		770
Depreciation Rate [Abstract]
Weighted-average depreciation rate												2.70%		2.10%		2.10%
Unbilled Receivables [Abstract]
Unbilled Receivables, Current		112					102					112		102
Allowance For Doubtful Accounts [Abstract]
Receivables, allowance for doubtful accounts		9					9					9		9		10
Assets and Liabilities, Current [Abstract]
Collateral Already Posted, Aggregate Fair Value		9					24					9		24
Employee-related Liabilities, Current		160	[1]				82	[1]				160	[1]	82	[1]
Customer Deposits, Current		120					116					120		116
Derivative Liabilities, Current		94	[2]				123	[2]				94	[2]	123	[2]
Income Amounts Attributable to Parent, Disclosures [Abstract]
Net Income Attributable to Duke Energy Corporation												272		516		603
Excise Taxes [Abstract]
Excise taxes												113		110		119
Progress Energy Florida [Member]
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents		131					16					131		16		249	17
Energy Related Inventory [Abstract]
Materials and supplies		269					301					269		301
Coal held for electric generation		344					358					344		358
Inventory, Net, Total		613					659					613		659
Depreciation Rate [Abstract]
Weighted-average depreciation rate												2.50%		2.40%		1.90%
Unbilled Receivables [Abstract]
Unbilled Receivables, Current		74					55					74		55
Allowance For Doubtful Accounts [Abstract]
Receivables, allowance for doubtful accounts		7					18					7		18		25
Assets and Liabilities, Current [Abstract]
Collateral Already Posted, Aggregate Fair Value		50					123					50		123
Employee-related Liabilities, Current		95	[1]				49	[1]				95	[1]	49	[1]
Derivative, Collateral, Obligation to Return Cash		1					3					1		3
Customer Deposits, Current		222					224					222		224
Derivative Liabilities, Current		127					220					127		220
Excise Taxes [Abstract]
Excise taxes												205		205		226
Duke Energy Ohio [Member]
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents		31					99					31		99		228	127
Restricted Cash [Abstract]
Restricted Cash		0					30					0		30
Energy Related Inventory [Abstract]
Materials and supplies		142					150					142		150
Coal held for electric generation		82					90					82		90
Natural gas		3					3					3		3
Inventory, Net, Total		227					243					227		243
Depreciation Rate [Abstract]
Weighted-average depreciation rate												3.20%		3.50%		4.10%
Unbilled Receivables [Abstract]
Unbilled Receivables, Current		47					50					47		50
Unbilled revenues sold to CRC		90					89					90		89
Allowance For Doubtful Accounts [Abstract]
Receivables, allowance for doubtful accounts		2					16					2		16		18
Assets and Liabilities, Current [Abstract]
Collateral Already Posted, Aggregate Fair Value		104					35					104		35
Derivative, Collateral, Obligation to Return Cash		92					28					92		28
Excise Taxes [Abstract]
Excise taxes												102		109		115
Duke Energy Ohio [Member] | Current Collateral Assets [Member]
Assets and Liabilities, Current [Abstract]
Collateral Already Posted, Aggregate Fair Value		99	[1]				31	[1]				99	[1]	31	[1]
Duke Energy Indiana [Member]
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents		36					16					36		16		54	20
Energy Related Inventory [Abstract]
Materials and supplies		164					134					164		134
Coal held for electric generation		216					196					216		196
Inventory, Net, Total		380					330					380		330
Depreciation Rate [Abstract]
Weighted-average depreciation rate												3.30%		3.40%		3.50%
Unbilled Receivables [Abstract]
Unbilled Receivables, Current		3					2					3		2
Unbilled revenues sold to CRC		132					115					132		115
Allowance For Doubtful Accounts [Abstract]
Receivables, allowance for doubtful accounts		1					1					1		1		1
Assets and Liabilities, Current [Abstract]
Derivative Liabilities, Current		63	[1]				1	[1]				63	[1]	1	[1]
Excise Taxes [Abstract]
Excise taxes												$ 33		$ 31		$ 29

[1] Does not exceed 5% of Total current assets or Total current liabilities at December 31, 2011.

[2] Does not exceed 5% of Total current assets or Total current liabilities at December 31, 2012.