Regulatory Matters (Narrative) (Details) (USD $)	3 Months Ended		6 Months Ended			3 Months Ended	6 Months Ended		0 Months Ended					3 Months Ended		6 Months Ended			0 Months Ended			3 Months Ended			3 Months Ended		6 Months Ended			3 Months Ended	6 Months Ended					3 Months Ended	6 Months Ended		3 Months Ended				3 Months Ended		6 Months Ended			0 Months Ended		12 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013	Jun. 30, 2014 Duke Energy Carolinas [Member]	Jun. 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]	Jun. 30, 2014 Duke Energy Carolinas [Member] William State Lee III Nuclear Station [Member]	Jun. 30, 2014 Duke Energy Carolinas [Member] William State Lee III Nuclear Station [Member] NCEMC [Member]	Jun. 30, 2014 Duke Energy Progress [Member]	Jun. 30, 2013 Duke Energy Progress [Member]	Jun. 30, 2014 Duke Energy Progress [Member]	Jun. 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]	Jun. 30, 2014 Duke Energy Progress [Member] FERC Mitigation [Member]	Jun. 30, 2013 Duke Energy Progress [Member] Shearon Harris Nuclear Station [Member]	Jun. 30, 2014 Duke Energy Progress [Member] Shearon Harris Nuclear Station [Member]	Jun. 30, 2014 Duke Energy Florida [Member]	Jun. 30, 2013 Duke Energy Florida [Member]	Jun. 30, 2014 Duke Energy Florida [Member]	Jun. 30, 2013 Duke Energy Florida [Member]	Dec. 31, 2013 Duke Energy Florida [Member]	Jun. 30, 2013 Duke Energy Florida [Member] Removal Costs [Member]	Jun. 30, 2013 Duke Energy Florida [Member] Removal Costs [Member]	Jun. 30, 2014 Duke Energy Florida [Member] 2013 FPSC Settlement Agreement [Member] New Generation Needs [Member]	Jun. 30, 2014 Duke Energy Florida [Member] Crystal River Unit 3 [Member]	Jun. 30, 2014 Duke Energy Florida [Member] Crystal River Unit 3 [Member] Amount Subject To Cost Cap [Member]	Jun. 30, 2014 Duke Energy Florida [Member] Crystal River Unit 3 [Member] Uprate and ISFSI Projects [Member]	Jun. 30, 2013 Duke Energy Florida [Member] Crystal River Unit 3 [Member] 2013 FPSC Settlement Agreement [Member]	Jun. 30, 2014 Duke Energy Florida [Member] Crystal River Unit 3 [Member] 2013 FPSC Settlement Agreement [Member]	Jun. 30, 2014 Duke Energy Florida [Member] Levy Nuclear Station [Member]	Jun. 30, 2013 Duke Energy Florida [Member] Levy Nuclear Station [Member] 2013 FPSC Settlement Agreement [Member]	Jun. 30, 2014 Duke Energy Florida [Member] Citrus County Station [Member]	Jun. 30, 2014 Duke Energy Florida [Member] Suwannee Station [Member]	Jun. 30, 2014 Duke Energy Florida [Member] Hines Energy Complex [Member]	Jun. 30, 2014 Duke Energy Ohio [Member]	Jun. 30, 2013 Duke Energy Ohio [Member]	Jun. 30, 2014 Duke Energy Ohio [Member]	Jun. 30, 2013 Duke Energy Ohio [Member]	Dec. 31, 2013 Duke Energy Ohio [Member]	Nov. 13, 2013 Duke Energy Ohio [Member] MGP Remidiation [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]	Jun. 30, 2014 Duke Energy Ohio [Member] RTO Realignment [Member]	Dec. 31, 2013 Duke Energy Ohio [Member] RTO Realignment [Member]	Jun. 30, 2014 Duke Energy Ohio [Member] Regional Transmission Organization [Member]	Jun. 30, 2014 Duke Energy Indiana [Member]	Dec. 31, 2013 Duke Energy Indiana [Member]	Jun. 30, 2014 Duke Energy Indiana [Member] Edwardsport IGCC Plant [Member] Edwardsport Event November 20, 2007 [Member]	Jun. 30, 2014 Duke Energy Indiana [Member] Edwardsport IGCC Plant [Member] Edwardsport Event December 27, 2012 [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													13.00%
Impairment charges	6,000,000	386,000,000	1,388,000,000	386,000,000		3,000,000	3,000,000							(18,000,000)	22,000,000	(18,000,000)	22,000,000					(18,000,000)	22,000,000			345,000,000	1,000,000	345,000,000								295,000,000			65,000,000				21,000,000		1,438,000,000
Regulatory assets, non current	9,009,000,000		9,009,000,000		9,191,000,000	1,509,000,000	1,509,000,000	1,527,000,000						1,428,000,000		1,428,000,000		1,384,000,000						48,000,000	2,609,000,000		2,609,000,000		2,729,000,000					1,337,000,000	281,000,000			18,000,000					461,000,000		461,000,000		471,000,000						74,000,000	669,000,000	717,000,000
Regulatory assets, current	1,349,000,000		1,349,000,000		895,000,000	388,000,000	388,000,000	295,000,000						369,000,000		369,000,000		127,000,000							273,000,000		273,000,000		221,000,000									95,000,000					71,000,000		71,000,000		57,000,000							173,000,000	118,000,000
Amount of reduction to carrying amount of regulatory liabilities																														17,000,000	73,000,000
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
Net unrecovered investment																																						233,000,000
Restructuring Reserve																																						25,000,000													94,000,000	95,000,000
Net property, plant and equipment	66,908,000,000		66,908,000,000		69,490,000,000	23,341,000,000	23,341,000,000	23,012,000,000						13,810,000,000		13,810,000,000		13,650,000,000							9,722,000,000		9,722,000,000		9,611,000,000									120,000,000					4,868,000,000		4,868,000,000		8,235,000,000							8,668,000,000	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