Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2012

Dec. 31, 2011

Asset Retirement Obligation [Line Items]

Schedule of Change in Asset Retirement Obligation

		Year Ended December 31, 2012
				Duke				Progress		Progress		Duke		Duke
		Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)		Energy		Carolinas		Energy		Carolinas		Florida		Ohio		Indiana
Balance as of January 1,	$	1,936	$	1,846	$	1,265	$	896	$	369	$	27	$	43
Acquisitions(a)		3,062		―		―		―		―		―		―
Accretion expense(b)		173		118		86		64		22		1		1
Liabilities settled		(15)		(3)		(2)		(2)		―		―		(10)
Revisions in estimates of cash flows(c)		(4)		(2)		234		―		234		―		(1)
Liabilities incurred in the current year(d)		24		―		837		698		139		―		4
Balance as of December 31(e)	$	5,176	$	1,959	$	2,420	$	1,656	$	764	$	28	$	37

			Year Ended December 31, 2011
					Duke				Progress		Progress		Duke		Duke
			Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)			Energy		Carolinas		Energy		Carolinas		Florida		Ohio		Indiana
Balance as of January 1,		$	1,816	$	1,728	$	1,200	$	849	$	351	$	27	$	46
Accretion expense(b)			111		105		67		49		18		2		2
Liabilities settled			(3)		(1)		―		―		―		(2)		―
Revisions in estimates of cash flows			1		9		(2)		(2)		―		―		(9)
Liabilities incurred in the current year			11		5		―		―		―		―		4
Balance as of December 31		$	1,936	$	1,846	$	1,265	$	896	$	369	$	27	$	43
(a)	Represents asset retirement obligations resulting from the merger with Progress Energy. See Note 2 for additional information.
(b)	Substantially all of the accretion expense for the years ended December 31, 2012 and 2011 relates to Duke Energy’s regulated electric operations and has been deferred in accordance with regulatory accounting treatment, as discussed above.
(c)	For Progress Energy and Progress Energy Florida, the amounts relate to the retirement of Crystal River Unit 3.
(d)	For Progress Energy, Progress Energy Carolinas and Progress Energy Florida, the amounts primarily relate to spent nuclear fuel disposal recorded in the third quarter of 2012 to conform to Duke Energy's assumptions for the types of estimated costs in the asset retirement obligations.
(e)	Includes $7 million reported in Other current liabilities on the Consolidated Balance Sheets at Duke Energy, Progress Energy and Progress Energy Carolinas.

Schedule of nuclear operating licenses expiration [Table Text Block]

Unit	Year of Expiration
Duke Energy Carolinas
Catawba Unit 1	2043
Catawba Unit 2	2043
McGuire Unit 1	2041
McGuire Unit 2	2043
Oconee Unit 1	2033
Oconee Unit 2	2033
Oconee Unit 3	2034
Progress Energy Carolinas
Brunswick Unit 1	2036
Brunswick Unit 2	2034
Harris	2046
Robinson	2030
Progress Energy Florida
Crystal River Unit 3	2016