Variable Interest Entities (Schedule Of Non-Consolidated VIEs) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Variable Interest Entity [Line Items]
Investments in equity method unconsolidated affiliates	$ 478		$ 483
Other Assets	2,466		2,399
Intangibles	356		372
Other Current Liabilities	2,068		2,511
Deferred Credits and Other Liabilities	26,332		26,442
Long-term Debt	39,662	[1]	39,461	[1]
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Investments in equity method unconsolidated affiliates	293		292
Other Assets	2		11
Intangibles	102		104
Total Assets	397		407
Other Current Liabilities	1		3
Deferred Credits and Other Liabilities	16		336
Total Liabilities	17		339
Net Assets	380		68
DukeNet [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Investments in equity method unconsolidated affiliates	117		118
Total Assets	117		118
Net Assets	117		118
Renewables [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Investments in equity method unconsolidated affiliates	149		147
Total Assets	149		147
Net Assets	149		147
Other VIEs [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Investments in equity method unconsolidated affiliates	27		27
Other Assets	2		2
Intangibles	102		104
Total Assets	131		133
Other Current Liabilities	1		3
Deferred Credits and Other Liabilities	16		17
Total Liabilities	17		20
Net Assets	114		113
FPC Capital I Trust [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Other Assets			9	[2]
Total Assets			9
Deferred Credits and Other Liabilities			319	[2]
Total Liabilities			319
Net Assets			(310)
Duke Energy Carolinas [Member]
Variable Interest Entity [Line Items]
Other Assets	941		934
Other Current Liabilities	409		490
Deferred Credits and Other Liabilities	10,826		10,602
Long-term Debt	8,740	[3]	8,741	[3]
Progress Energy [Member]
Variable Interest Entity [Line Items]
Other Assets	531		530
Other Current Liabilities	924		1,118
Deferred Credits and Other Liabilities	9,586		9,755
Long-term Debt	14,224		14,428
Progress Energy [Member] | FPC Capital I Trust [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Other Assets			9
Deferred Credits and Other Liabilities			274
Duke Energy Progress [Member]
Variable Interest Entity [Line Items]
Other Assets	269		251
Other Current Liabilities	407		517
Deferred Credits and Other Liabilities	6,572		6,451
Long-term Debt	5,336		4,840
Duke Energy Florida [Member]
Variable Interest Entity [Line Items]
Other Assets	176		182
Other Current Liabilities	461		534
Deferred Credits and Other Liabilities	3,844		3,934
Long-term Debt	4,894		5,320
Duke Energy Ohio [Member]
Variable Interest Entity [Line Items]
Other Assets	53		75
Intangibles	124		129
Other Current Liabilities	117		126
Deferred Credits and Other Liabilities	2,475		2,473
Long-term Debt	1,994		1,997
Duke Energy Ohio [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Accounts Receivable, Net	115		97
Intangibles	102		104
Total Assets	217		201
Net Assets	217		201
Duke Energy Indiana [Member]
Variable Interest Entity [Line Items]
Other Assets	130		122
Intangibles	37		41
Other Current Liabilities	146		165
Deferred Credits and Other Liabilities	2,080		2,005
Long-term Debt	3,702		3,702
Duke Energy Indiana [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Accounts Receivable, Net	135		116
Total Assets	135		116
Net Assets	$ 135		$ 116

[1] Includes book value of Non-recourse long-term debt of variable interest entities of $1,255 million and $852 million March 31, 2013 and December 31, 2012, respectively.

[2] The entire balance of Investments and other assets and $274 million of the Deferred credits and other liabilities balance applies to Progress Energy.

[3] Includes book value of Non-recourse long-term debt of variable interest entities of $300 million at both March 31, 2013 and December 31, 2012, respectively.