Regulatory Matters (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended					3 Months Ended	9 Months Ended		0 Months Ended					3 Months Ended		9 Months Ended			0 Months Ended			3 Months Ended			3 Months Ended		9 Months Ended			3 Months Ended	9 Months Ended					3 Months Ended	9 Months Ended		3 Months Ended				3 Months Ended		9 Months Ended			0 Months Ended		12 Months Ended								9 Months Ended			9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Sep. 30, 2014 Atlantic Coast Pipeline [Member]	Sep. 30, 2014 Atlantic Coast Pipeline [Member] Dominion Resources [Member]	Sep. 30, 2014 Duke Energy Carolinas [Member]	Sep. 30, 2014 Duke Energy Carolinas [Member]	Dec. 31, 2013 Duke Energy Carolinas [Member]	Sep. 24, 2013 Duke Energy Carolinas [Member] Rate Case [Member] NCUC [Member]	Sep. 24, 2013 Duke Energy Carolinas [Member] Rate Case Step One [Member] NCUC [Member]	Sep. 24, 2013 Duke Energy Carolinas [Member] Rate Case Step Two [Member] NCUC [Member]	Sep. 30, 2014 Duke Energy Carolinas [Member] William State Lee III Nuclear Station [Member]	Sep. 30, 2014 Duke Energy Carolinas [Member] William State Lee III Nuclear Station [Member] NCEMC [Member]	Sep. 30, 2014 Duke Energy Progress [Member]	Sep. 30, 2013 Duke Energy Progress [Member]	Sep. 30, 2014 Duke Energy Progress [Member]	Sep. 30, 2013 Duke Energy Progress [Member]	Dec. 31, 2013 Duke Energy Progress [Member]	May 30, 2013 Duke Energy Progress [Member] Rate Case [Member] NCUC [Member]	May 30, 2013 Duke Energy Progress [Member] Rate Case Step One [Member] NCUC [Member]	May 30, 2013 Duke Energy Progress [Member] Rate Case Step Two [Member] NCUC [Member]	Sep. 30, 2014 Duke Energy Progress [Member] FERC Mitigation [Member]	Sep. 30, 2013 Duke Energy Progress [Member] Shearon Harris Nuclear Station [Member]	Sep. 30, 2014 Duke Energy Progress [Member] Shearon Harris Nuclear Station [Member]	Sep. 30, 2014 Duke Energy Florida [Member]	Sep. 30, 2013 Duke Energy Florida [Member]	Sep. 30, 2014 Duke Energy Florida [Member]	Sep. 30, 2013 Duke Energy Florida [Member]	Dec. 31, 2013 Duke Energy Florida [Member]	Sep. 30, 2013 Duke Energy Florida [Member] Removal Costs [Member]	Sep. 30, 2013 Duke Energy Florida [Member] Removal Costs [Member]	Sep. 30, 2014 Duke Energy Florida [Member] 2013 FPSC Settlement Agreement [Member] New Generation Needs [Member]	Sep. 30, 2014 Duke Energy Florida [Member] Crystal River Unit 3 [Member]	Sep. 30, 2014 Duke Energy Florida [Member] Crystal River Unit 3 [Member] Amount Subject To Cost Cap [Member]	Sep. 30, 2014 Duke Energy Florida [Member] Crystal River Unit 3 [Member] Uprate and ISFSI Projects [Member]	Sep. 30, 2013 Duke Energy Florida [Member] Crystal River Unit 3 [Member] 2013 FPSC Settlement Agreement [Member]	Sep. 30, 2014 Duke Energy Florida [Member] Crystal River Unit 3 [Member] 2013 FPSC Settlement Agreement [Member]	Sep. 30, 2014 Duke Energy Florida [Member] Levy Nuclear Station [Member]	Sep. 30, 2013 Duke Energy Florida [Member] Levy Nuclear Station [Member] 2013 FPSC Settlement Agreement [Member]	Sep. 30, 2014 Duke Energy Florida [Member] Citrus County Station [Member]	Sep. 30, 2014 Duke Energy Florida [Member] Suwannee Station [Member]	Sep. 30, 2014 Duke Energy Florida [Member] Hines Energy Complex [Member]	Sep. 30, 2014 Duke Energy Ohio [Member]	Sep. 30, 2013 Duke Energy Ohio [Member]	Sep. 30, 2014 Duke Energy Ohio [Member]	Sep. 30, 2013 Duke Energy Ohio [Member]	Dec. 31, 2013 Duke Energy Ohio [Member]	Nov. 13, 2013 Duke Energy Ohio [Member] MGP Remediation [Member] PUCO [Member]	Nov. 13, 2013 Duke Energy Ohio [Member] Natural Gas Rate Case [Member] PUCO [Member]	Dec. 31, 2012 Duke Energy Ohio [Member] RTO Realignment [Member]	Sep. 30, 2014 Duke Energy Ohio [Member] RTO Realignment [Member]	Dec. 31, 2013 Duke Energy Ohio [Member] RTO Realignment [Member]	Sep. 30, 2014 Duke Energy Ohio [Member] Regional Transmission Organization [Member]	Aug. 18, 2014 Duke Energy Ohio [Member] W.C. Beckjord Station [Member] gal	Sep. 30, 2014 Duke Energy Indiana [Member]	Dec. 31, 2013 Duke Energy Indiana [Member]	Sep. 30, 2014 Duke Energy Indiana [Member] Grid Infrastructure Improvement Plan [Member]	Sep. 30, 2014 Duke Energy Indiana [Member] Edwardsport IGCC Plant [Member]	Sep. 30, 2014 Duke Energy Indiana [Member] Edwardsport IGCC Plant [Member] Edwardsport Event November 20, 2007 [Member]	Sep. 30, 2014 Duke Energy Indiana [Member] Edwardsport IGCC Plant [Member] Edwardsport Event December 27, 2012 [Member]	Sep. 30, 2014 Duke Energy Indiana [Member] Edwardsport IGCC Plant [Member] Edwardsport Event September 8, 2014 [Member]
Public Utilities, General Disclosures [Line Items]
Approved rate increase amount by state commission												$ 204,000,000	$ 30,000,000									$ 147,000,000	$ 31,000,000																											$ 56,000,000
Approved percentage rate increase by state commission												4.50%	0.60%									4.50%	1.00%
Approved return on equity percentage amount by state commission											10.20%										10.20%													10.50%					7.35%												9.84%
Rate increase begin date											Sep. 25, 2013										Jun. 01, 2013
Approved equity capital structure, percentage											53.00%										53.00%
Joint owner ownership percentage						40.00%	45.00%								13.00%
Impairment charges	1,000,000	2,000,000	81,000,000	388,000,000					3,000,000									(18,000,000)	22,000,000					(18,000,000)	22,000,000		1,000,000	1,000,000	2,000,000	346,000,000								295,000,000			65,000,000						94,000,000
Regulatory assets, noncurrent	10,252,000,000		10,252,000,000		9,191,000,000			1,986,000,000	1,986,000,000	1,527,000,000						2,187,000,000		2,187,000,000		1,384,000,000						48,000,000	2,631,000,000		2,631,000,000		2,729,000,000					1,373,000,000	268,000,000			54,000,000					480,000,000		480,000,000		471,000,000						74,000,000		670,000,000	717,000,000
Regulatory assets, current	1,232,000,000		1,232,000,000		895,000,000			388,000,000	388,000,000	295,000,000						325,000,000		325,000,000		127,000,000							241,000,000		241,000,000		221,000,000									33,000,000					67,000,000		67,000,000		57,000,000								134,000,000	118,000,000
Amount of reduction to carrying amount of regulatory liabilities																																22,000,000	95,000,000
Gallons of Fuel Released																																																								9,000
Decommissioning cost study estimate																																			1,180,000,000
Acceleration of cash recovery through fuel clause																																							130,000,000
Cost Cap for customers																																							1,466,000,000																							2,595,000,000
Percent of AFUDC Allowed																																																												85.00%
Net unrecovered investment																																								207,000,000
Restructuring Reserve																																								25,000,000													95,000,000	95,000,000
Net property, plant and equipment	69,595,000,000		69,595,000,000		69,490,000,000			25,126,000,000	25,126,000,000	23,012,000,000						14,580,000,000		14,580,000,000		13,650,000,000							9,815,000,000		9,815,000,000		9,611,000,000									120,000,000					4,905,000,000		4,905,000,000		8,235,000,000								8,780,000,000	8,576,000,000
MISO estimate of Duke Energy Ohio's MVP obligation																																																				2,700,000,000
Estimated capital cost of new utility plant, including AFUDC														600,000,000																												1,500,000,000	197,000,000	160,000,000																	1,985,000,000
Allowance for Funds Used During Construction, Capitalized Interest																																																															61,000,000
Estimated capital cost																																																											$ 1,900,000,000