Commitments and Contingencies (Narrative) (Details) (USD $)					3 Months Ended							3 Months Ended									3 Months Ended	12 Months Ended						3 Months Ended
	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2014 Minimum [Member]	Mar. 31, 2014 Maximum [Member]	Mar. 31, 2014 Brazil Expansion Lawsuit [Member]	Mar. 31, 2014 Duke Energy Carolinas [Member]		Dec. 31, 2013 Duke Energy Carolinas [Member]		Mar. 31, 2014 Duke Energy Carolinas [Member] North Carolina Ash Basins [Member] Dan River Steam Station [Member]	Mar. 31, 2014 Duke Energy Carolinas [Member] North Carolina Ash Basins [Member] Dan River Steam Station [Member] Minimum [Member] gal T	Mar. 31, 2014 Duke Energy Carolinas [Member] North Carolina Ash Basins [Member] Dan River Steam Station [Member] Maximum [Member] T gal	Mar. 31, 2014 Duke Energy Carolinas [Member] New Source Review Provisions Of Clean Air Act [Member]	Mar. 31, 2014 Duke Energy Carolinas [Member] Asbestos Issue [Member]	Dec. 31, 2013 Duke Energy Carolinas [Member] Asbestos Issue [Member]	Mar. 31, 2014 Duke Energy Carolinas [Member] Asbestos Issue [Member] Malignant Asbestos Claim [Member] Claims	Mar. 31, 2014 Duke Energy Carolinas [Member] Asbestos Issue [Member] Non Malignant Asbestos Claim [Member] Claims	Mar. 31, 2014 Progress Energy [Member]	Mar. 31, 2014 Progress Energy [Member] Synthetic Fuels [Member]	Dec. 31, 2009 Progress Energy [Member] Synthetic Fuels [Member]	Dec. 31, 2012 Progress Energy [Member] Synthetic Fuels [Member]	Mar. 31, 2014 Duke Energy Progress [Member]	Mar. 31, 2014 Duke Energy Progress [Member] Spent Nuclear Fuels [Member]	Mar. 31, 2014 Duke Energy Florida [Member]	Mar. 31, 2014 Duke Energy Florida [Member] Spent Nuclear Fuels [Member]	Mar. 31, 2014 Duke Energy Florida [Member] Westinghouse Electric Company Litigation [Member]	Mar. 31, 2014 Duke Energy Ohio [Member]	Mar. 31, 2014 Duke Energy Indiana [Member]	Mar. 31, 2014 Duke Energy Indiana [Member] Edwardsport IGCC Plant [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, range of possible loss, portion not acccrued	$ 75,000,000							$ 29,000,000												$ 5,000,000				$ 2,000,000		$ 3,000,000			$ 35,000,000	$ 6,000,000
Estimated cost of complying with recently issued and proposed EPA regulations					5,000,000,000	6,000,000,000
Loss contingency, damages sought, value																												510,000,000
Obligation to expand installed generation capacity, percent							15.00%
Maximum civil penalties per day for each violation															37,500
Loss contingency, pending claims, number																		29	112
Asbestos-related injuries and damages reserves																609,000,000	616,000,000	10,000,000	25,000,000
Reinsurance retention policy, amount retained																476,000,000
Reinsurance retention policy, excess retention, amount reinsured																897,000,000
Probable insurance recoveries	649,000,000	[1],[2]	649,000,000	[1],[2]				649,000,000	[1],[2]	649,000,000	[1],[2]
Loss contingency, damages paid, value																						154,000,000
Damages awarded to plaintiff																					90,000,000
Gain recognized in period																							63,000,000
Gain contingency, unrecorded amount																									83,000,000		21,000,000	54,000,000			560,000,000
Coal ash released, in tons													30,000	39,000
Basin water released, in gallons													24,000,000	27,000,000
Environmental remediation expense												$ 15,000,000

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

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