Variable Interest Entities (Schedule Of Non-Consolidated VIEs) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Investments in equity method unconsolidated affiliates	$ 450	$ 460
Intangibles	357	363
Other Current Liabilities	1,434	1,091
Deferred Credits and Other Liabilities	15,922	15,454
Duke Energy Carolinas [Member]
Other Current Liabilities	481	398
Deferred Credits and Other Liabilities	10,150	9,736
Duke Energy Ohio [Member]
Intangibles	136	143
Other Current Liabilities	117	122
Deferred Credits and Other Liabilities	2,507	2,490
Duke Energy Indiana [Member]
Intangibles	44	50
Other Current Liabilities	132	93
Deferred Credits and Other Liabilities	2,004	2,079
Non-Consolidated VIEs [Member]
Investments in equity method unconsolidated affiliates	226	235
Intangibles	108	111
Total Assets	334	346
Other Current Liabilities	3	3
Deferred Credits and Other Liabilities	17	18
Total Liabilities	20	21
Net Assets	314	325
Non-Consolidated VIEs [Member] | DukeNet [Member]
Investments in equity method unconsolidated affiliates	122	129
Total Assets	122	129
Net Assets	122	129
Non-Consolidated VIEs [Member] | Renewables [Member]
Investments in equity method unconsolidated affiliates	79	81
Total Assets	79	81
Net Assets	79	81
Non-Consolidated VIEs [Member] | Other VIEs [Member]
Investments in equity method unconsolidated affiliates	25	25
Intangibles	108	111
Total Assets	133	136
Other Current Liabilities	3	3
Deferred Credits and Other Liabilities	17	18
Total Liabilities	20	21
Net Assets	113	115
Non-Consolidated VIEs [Member] | Duke Energy Ohio [Member]
Accounts Receivable, Net	101	129
Intangibles	108	111
Total Assets	209	240
Net Assets	209	240
Non-Consolidated VIEs [Member] | Duke Energy Indiana [Member]
Accounts Receivable, Net	143	139
Total Assets	143	139
Net Assets	$ 143	$ 139