Property, Plant And Equipment (Schedule Of Property, Plant And Equipment) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010
Land	$ 745		$ 743
Nuclear fuel	1,213		1,176
Equipment	863	[1]	718	[2]
Construction in process	7,664	[1]	7,015	[2]
Other	2,477	[1]	2,354	[2]
Total property, plant and equipment	61,450		58,539
Total net property, plant and equipment	42,661		40,344
Capitalized leases	444		414
Accumulated amortization on capitalized leases	28		31
Variable Interest Entity [Member]
Total accumulated depreciation	62		45
Regulated Operation [Member]
Total accumulated depreciation	(16,630)	[3],[4]	(16,273)	[5],[6]
Unregulated Operation [Member]
Total accumulated depreciation	(2,159)	[4],[7]	(1,922)	[6],[8]
Electric [Member] | Regulated Operation [Member]
Plant - transmission and distribution	38,330	[1]	36,744	[2]
Electric [Member] | Unregulated Operation [Member]
Plant - transmission and distribution	5,464	[1]	5,256	[2]
Natural Gas [Member] | Regulated Operation [Member]
Plant - transmission and distribution	1,927	[1]	1,815	[2]
Other Buildings And Improvements [Member] | Regulated Operation [Member]
Other	672	[1]	610	[2]
Other Buildings And Improvements [Member] | Unregulated Operation [Member]
Other	2,095	[1]	2,108	[2]
Nuclear Fuel [Member]
Total accumulated depreciation	$ (578)		$ 667
Minimum [Member]
Equipment, estimated useful life, years	3		3
Other, estimated useful life, in years	5		5
Minimum [Member] | Electric [Member] | Regulated Operation [Member]
Plant - transmission and distribution, estimated useful life, in years	8		8
Minimum [Member] | Electric [Member] | Unregulated Operation [Member]
Plant - transmission and distribution, estimated useful life, in years	8		8
Minimum [Member] | Natural Gas [Member] | Regulated Operation [Member]
Plant - transmission and distribution, estimated useful life, in years	12		12
Minimum [Member] | Other Buildings And Improvements [Member] | Regulated Operation [Member]
Other, estimated useful life, in years	25		25
Minimum [Member] | Other Buildings And Improvements [Member] | Unregulated Operation [Member]
Other, estimated useful life, in years	18		20
Maximum [Member]
Equipment, estimated useful life, years	33		33
Other, estimated useful life, in years	33		33
Maximum [Member] | Electric [Member] | Regulated Operation [Member]
Plant - transmission and distribution, estimated useful life, in years	125		125
Maximum [Member] | Electric [Member] | Unregulated Operation [Member]
Plant - transmission and distribution, estimated useful life, in years	100		100
Maximum [Member] | Natural Gas [Member] | Regulated Operation [Member]
Plant - transmission and distribution, estimated useful life, in years	60		60
Maximum [Member] | Other Buildings And Improvements [Member] | Regulated Operation [Member]
Other, estimated useful life, in years	100		100
Maximum [Member] | Other Buildings And Improvements [Member] | Unregulated Operation [Member]
Other, estimated useful life, in years	40		90

[1] Includes capitalized leases of $444 million, $53 million, $82 million, and $33 million at Duke Energy, Duke Energy Carolinas, Duke Energy Ohio, and Duke Energy Indiana, respectively.

[2] Includes capitalized leases of $414 million, $134 million, and $53 million at Duke Energy, Duke Energy Ohio, and Duke Energy Indiana, respectively.

[3] Includes $578 million of accumulated amortization of nuclear fuel at Duke Energy and Duke Energy Carolinas.

[4] Includes accumulated amortization of capitalized leases of $28 million, an insignificant amount, $11 million and $6 million at Duke Energy, Duke Energy Carolinas, Duke Energy Ohio, and Duke Energy Indiana, respectively.

[5] Includes $667 million of accumulated amortization of nuclear fuel at Duke Energy and Duke Energy Carolinas.

[6] Includes accumulated amortization of capitalized leases of $31 million, $17 million and $10 million at Duke Energy, Duke Energy Ohio, and Duke Energy Indiana, respectively.

[7] Includes accumulated depreciation of VIEs of $62 million at December 31, 2011 at Duke Energy.

[8] Includes accumulated depreciation of VIEs of $45 million at December 31, 2010 at Duke Energy.