Commitments And Contingencies (Narrative) (Details) (USD $)	6 Months Ended		60 Months Ended
	Jun. 30, 2012		Dec. 31, 2016	Dec. 31, 2011
Estimated cost of installing synthetic caps and liners at exisitng and new CCP landfills			$ 259,000,000
Probable insurance recoveries	813,000,000	[1],[2]		813,000,000	[1],[2]
Reserves for legal matters	792,000,000	[3],[4]		810,000,000	[3],[4]
Duke Energy Carolinas [Member]
Estimated cost of installing synthetic caps and liners at exisitng and new CCP landfills			78,000,000
Federal Clean Coal Tax Credits	125,000,000
Probable insurance recoveries	813,000,000	[1],[2]		813,000,000	[1],[2]
Reserves for legal matters	776,000,000	[3],[4]		801,000,000	[3],[4]
Duke Energy Ohio [Member]
Reserve for remediation work at former MGP sites	22,000,000
Amount of deferred costs related to former MGP sites	75,000,000
Estimated cost of installing synthetic caps and liners at exisitng and new CCP landfills			63,000,000
Duke Energy Indiana [Member]
Estimated cost of installing synthetic caps and liners at exisitng and new CCP landfills			118,000,000
Federal Clean Coal Tax Credits	134,000,000
Reserves for legal matters	8,000,000	[3]		4,000,000	[3]
Paranapanema Lawsuit [Member]
Additional assessment under resolutions promulgated by ANEEL	59,000,000
Fines imposed by ANEEL due to DEIGP's refusal to pay additional assessments	9,000,000
Pre-tax charge recorded	33,000,000
Brazil Expansion Lawsuit [Member]
Obligation to expand installed generation capacity, percent	15.00%
Crescent Litigation [Member]
Amount of claim(s)	1,200,000,000
Asbestos Issue [Member] | Duke Energy Carolinas [Member]
Number of nonmalignant asbestos related claims	188
Cumulative relief sought for nonmalignant asbestos related claims	47,000,000
Number of malignant asbestos related claims	58
Cumulative relief sought for malignant asbestos related claims	21,000,000
Asbestos-related injuries and damages reserves	776,000,000			801,000,000
Asbestos related injuries and damages self insured retention	476,000,000
Policy limit for potential future insurance recoveries for indemnification and medical cost claim payments in excess of self insured limit	968,000,000
Probable insurance recoveries	(813,000,000)			(813,000,000)
Minimum [Member]
Estimated cost of complying with recently issued and proposed EPA regulations	4,500,000,000
Minimum [Member] | Alaskan Global Warming Lawsuit [Member]
Amount of claim(s)	95,000,000
Maximum [Member]
Estimated cost of complying with recently issued and proposed EPA regulations	5,000,000,000
Maximum [Member] | Alaskan Global Warming Lawsuit [Member]
Amount of claim(s)	$ 400,000,000

[1] Insurance recoveries are classified in the respective Condensed Consolidated Balance Sheets in Other within Investments and Other Assets and Receivables.

[2] Relates to recoveries associated with aforementioned asbestos-related injuries and damages claims.

[3] Reserves are classified in the respective Condensed Consolidated Balance Sheets in Other within Deferred Credits and Other Liabilities and Other within Current Liabilities.

[4] Includes reserves for aforementioned asbestos-related injuries and damages claims.