Commitments and Contingencies (Narrative) (Details) (USD $)		6 Months Ended		6 Months Ended	0 Months Ended		6 Months Ended						0 Months Ended	12 Months Ended						3 Months Ended
	Jun. 30, 2014	Jun. 30, 2014 Brazil Expansion Lawsuit [Member]	Jun. 30, 2014 Duke Energy Carolinas [Member]	Jun. 30, 2014 Duke Energy Carolinas [Member] North Carolina Ash Basins [Member] Dan River Steam Station [Member]	Feb. 21, 2014 Duke Energy Carolinas [Member] North Carolina Ash Basins [Member] Minimum [Member] Dan River Steam Station [Member] T gal	Feb. 21, 2014 Duke Energy Carolinas [Member] North Carolina Ash Basins [Member] Maximum [Member] Dan River Steam Station [Member] gal T	Jun. 30, 2014 Duke Energy Carolinas [Member] New Source Review Provisions Of Clean Air Act [Member]	Jun. 30, 2014 Duke Energy Carolinas [Member] Asbestos Issue [Member]	Dec. 31, 2013 Duke Energy Carolinas [Member] Asbestos Issue [Member]	Jun. 30, 2014 Duke Energy Carolinas [Member] Asbestos Issue [Member] Malignant Asbestos Claim [Member] Claims	Jun. 30, 2014 Duke Energy Carolinas [Member] Asbestos Issue [Member] Non Malignant Asbestos Claim [Member] Claims	Jun. 30, 2014 Progress Energy [Member]	Oct. 03, 2012 Progress Energy [Member] Synthetic Fuels [Member]	Dec. 31, 2009 Progress Energy [Member] Synthetic Fuels [Member]	Dec. 31, 2012 Progress Energy [Member] Synthetic Fuels [Member]	Jun. 30, 2014 Duke Energy Progress [Member]	Mar. 24, 2014 Duke Energy Progress [Member] Spent Nuclear Fuels [Member]	Jun. 30, 2014 Duke Energy Florida [Member]	Mar. 24, 2014 Duke Energy Florida [Member] Spent Nuclear Fuels [Member]	Mar. 31, 2014 Duke Energy Florida [Member] Westinghouse Electric Company Litigation [Member]	Mar. 28, 2014 Duke Energy Florida [Member] Westinghouse Electric Company Litigation [Member]	Jun. 30, 2014 Duke Energy Indiana [Member]	Dec. 11, 2012 Duke Energy Indiana [Member] Edwardsport IGCC Plant [Member]
Valuation and Qualifying Accounts [Abstract]
Coal ash released, in tons					30,000	39,000
Basin water released, in gallons					24,000,000	27,000,000
Environmental remediation expense				$ 20,000,000
Obligation to expand installed generation capacity, percent		15.00%
Maximum civil penalties per day for each violation							37,500
Loss contingency, pending claims, number										35	90
Asbestos-related injuries and damages reserves								600,000,000	616,000,000	12,000,000	19,000,000
Reinsurance retention policy, amount retained								476,000,000
Reinsurance retention policy, excess retention, amount reinsured								897,000,000
Probable insurance recoveries								649,000,000	649,000,000
Loss contingency, damages paid, value														154,000,000
Damages awarded to plaintiff													90,000,000
Gain recognized in period															63,000,000
Loss contingency, damages sought, value																				510,000,000
Loss contingency, range of possible loss, portion not acccrued	90,000,000		25,000,000									9,000,000				2,000,000		7,000,000				5,000,000
Gain contingency, unrecorded amount																	$ 83,000,000		$ 21,000,000		$ 54,000,000		$ 560,000,000