Variable Interest Entities (Schedule Of Non-Consolidated VIEs) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Investments in equity method unconsolidated affiliates	$ 542	$ 460
Intangibles	359	363
Total Assets	9
Other Current Liabilities	2,206	1,091
Deferred Credits and Other Liabilities	26,255	15,454
Duke Energy Carolinas [Member]
Other Current Liabilities	519	398
Deferred Credits and Other Liabilities	10,428	9,736
Duke Energy Ohio [Member]
Intangibles	132	143
Other Current Liabilities	105	122
Deferred Credits and Other Liabilities	2,507	2,490
Duke Energy Indiana [Member]
Intangibles	43	50
Other Current Liabilities	170	93
Deferred Credits and Other Liabilities	1,934	2,079
Non-Consolidated VIEs [Member]
Investments in equity method unconsolidated affiliates	310	235
Intangibles	106	111
Total Assets	416	346
Other Current Liabilities	2	3
Deferred Credits and Other Liabilities	337	18
Total Liabilities	339	21
Net Assets	77	325
Non-Consolidated VIEs [Member] | DukeNet [Member]
Investments in equity method unconsolidated affiliates	120	129
Total Assets	120	129
Net Assets	120	129
Non-Consolidated VIEs [Member] | Renewables [Member]
Investments in equity method unconsolidated affiliates	154	81
Total Assets	154	81
Net Assets	154	81
Non-Consolidated VIEs [Member] | Other VIEs [Member]
Investments in equity method unconsolidated affiliates	27	25
Intangibles	106	111
Total Assets	133	136
Other Current Liabilities	2	3
Deferred Credits and Other Liabilities	17	18
Total Liabilities	19	21
Net Assets	114	115
Non-Consolidated VIEs [Member] | FPC Capital I Trust [Member]
Investments in equity method unconsolidated affiliates	9
Deferred Credits and Other Liabilities	320
Total Liabilities	320
Net Assets	(311)
Non-Consolidated VIEs [Member] | Duke Energy Ohio [Member]
Accounts Receivable, Net	85	129
Intangibles	106	111
Total Assets	191	240
Net Assets	191	240
Non-Consolidated VIEs [Member] | Duke Energy Indiana [Member]
Accounts Receivable, Net	118	139
Total Assets	118	139
Net Assets	$ 118	$ 139