Commitments and Contingencies (Narrative) (Details)							1 Months Ended	3 Months Ended	12 Months Ended
	Sep. 29, 2016 USD ($)	Sep. 23, 2016 USD ($)	Feb. 08, 2016 USD ($)	Apr. 22, 2015 USD ($)	Mar. 10, 2015 USD ($)	Feb. 20, 2015 USD ($)	Dec. 31, 2016 USD ($) plant Claims reactor	Dec. 31, 2016 USD ($) plant Claims reactor	Dec. 31, 2016 USD ($) plant Claims reactor	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Aug. 18, 2014 gal	Mar. 31, 2014 USD ($)	Feb. 28, 2014 gal T
Insurance [Abstract]
Insured public liability limit per nuclear incident							$ 13,400,000,000	$ 13,400,000,000	$ 13,400,000,000
Excess nuclear liability program coverage							13,000,000,000	13,000,000,000	13,000,000,000
Pro rata assessment for each reactor owned for each incident exceeding public liability insurance							$ 127,000,000	$ 127,000,000	$ 127,000,000
Number of licensed nuclear reactors | reactor							102	102	102
Annual payment limit to pro rata assessments							$ 19,000,000	$ 19,000,000	$ 19,000,000
Industry aggregate limit							3,200,000,000	3,200,000,000	3,200,000,000
Sublimit for non-nuclear terrorist events							$ 1,830,000,000	$ 1,830,000,000	$ 1,830,000,000
Insurance Coverage Percentage Initial Weeks							100.00%	100.00%	100.00%
Accidental Outage Insurance Coverage Initial Weeks									365 days
Insurance Coverage Percentage Additional Weeks							80.00%	80.00%	80.00%
Accidental Outage Insurance Coverage Additional Weeks									770 days
Weeks of Sublimits for Accidental Outage Coverage									728 days
Sublimit accidental outage recovery							$ 328,000,000	$ 328,000,000	$ 328,000,000
Maximum Magnitude of Retroactive Premiums							10	10	10
Maximum Period for Retroactive Premium Assessment									6 years
North Carolina Ash Basins [Member]
Valuation and Qualifying Accounts [Abstract]
Facilities with Ash Basins | plant							14	14	14
Progress Energy Merger Shareholder Litigation [Member]
Valuation and Qualifying Accounts [Abstract]
Litigation Settlement, Amount					$ 146,000,000
Payments for Legal Settlements				$ 25,000,000
Litigation Settlement Covered by Insurance				$ 121,000,000
Gain contingency, unrecorded amount							$ 27,000,000	$ 27,000,000	$ 27,000,000
NCDEQ State Enforcement Actions [Member]
Valuation and Qualifying Accounts [Abstract]
Number of Plants with No Disputed Facts | plant							7	7	7
Facilities with Ash Basins | plant							14	14	14
Potential Groundwater Claims [Member]
Valuation and Qualifying Accounts [Abstract]
Facilities with Ash Basins | plant							14	14	14
Goodwill Payment							$ 5,000	$ 5,000	$ 5,000
Water Bill Stipend Period									25 years
Ash Basins Fines and Restitution [Member] | USDOJ [Member]
Valuation and Qualifying Accounts [Abstract]
Litigation Settlement, Expense						$ 68,000,000
Ash Basins Community Service and Mitigation [Member] | USDOJ [Member]
Valuation and Qualifying Accounts [Abstract]
Litigation Settlement, Expense						$ 34,000,000
Duke Energy Carolinas [Member]
Insurance [Abstract]
Primary nuclear liability program coverage							375,000,000	375,000,000	$ 375,000,000
Primary Nuclear Liability Coverage after January 2017									450,000,000
Max Retroactive Premium Assessments									164,000,000
Duke Energy Carolinas [Member] | McGuire Nuclear Station [Member]
Insurance [Abstract]
Sublimit property damage losses							1,500,000,000	1,500,000,000	1,500,000,000
Additional nuclear accident limit							1,250,000,000	1,250,000,000	1,250,000,000
Accidental outage insurance coverage policy limit							490,000,000	490,000,000	490,000,000
Duke Energy Carolinas [Member] | Catawba Nuclear Station [Member]
Insurance [Abstract]
Sublimit property damage losses							1,500,000,000	1,500,000,000	1,500,000,000
Dedicated additional nuclear accident limit							1,250,000,000	1,250,000,000	1,250,000,000
Additional Non Nuclear Accident Limit							750,000,000	750,000,000	750,000,000
Accidental outage insurance coverage policy limit							$ 490,000,000	$ 490,000,000	$ 490,000,000
Potential Obligation percentage							100.00%	100.00%	100.00%
Duke Energy Carolinas [Member] | Oconee Nuclear Station [Member]
Insurance [Abstract]
Sublimit property damage losses							$ 1,500,000,000	$ 1,500,000,000	$ 1,500,000,000
Additional nuclear accident limit							1,250,000,000	1,250,000,000	1,250,000,000
Additional Non Nuclear Accident Limit							750,000,000	750,000,000	750,000,000
Accidental outage insurance coverage policy limit							464,000,000	464,000,000	464,000,000
Duke Energy Carolinas [Member] | North Carolina Ash Basins [Member] | USDOJ [Member]
Valuation and Qualifying Accounts [Abstract]
Minimum Master Credit Facility Balance required							250,000,000	250,000,000	250,000,000
Duke Energy Carolinas [Member] | North Carolina Ash Basins [Member] | Dan River [Member]
Valuation and Qualifying Accounts [Abstract]
Litigation Settlement, Amount		$ (6,000,000)
Civil Penalty Assessed			$ 6,800,000
Duke Energy Carolinas [Member] | North Carolina Ash Basins [Member] | Dan River [Member] | Minimum [Member]
Valuation and Qualifying Accounts [Abstract]
Estimated amount of ash released, in tons | T														30,000
Estimated amount of ash basin water released, in gallons | gal														24,000,000
Duke Energy Carolinas [Member] | North Carolina Ash Basins [Member] | Dan River [Member] | Maximum [Member]
Valuation and Qualifying Accounts [Abstract]
Estimated amount of ash released, in tons | T														39,000
Estimated amount of ash basin water released, in gallons | gal														27,000,000
Duke Energy Carolinas [Member] | North Carolina Ash Basins [Member] | Operating Expense [Member] | USDOJ [Member]
Valuation and Qualifying Accounts [Abstract]
Litigation Settlement, Expense											$ 72,000,000
Duke Energy Carolinas [Member] | Groundwater Violation [Member]
Valuation and Qualifying Accounts [Abstract]
Charge for settlement agreement									1,000,000
Duke Energy Carolinas [Member] | Potential Groundwater Claims [Member]
Valuation and Qualifying Accounts [Abstract]
Settlement Offer Expense							18,000,000
Duke Energy Carolinas [Member] | Asbestos Issue [Member]
Valuation and Qualifying Accounts [Abstract]
Asbestos-related injuries and damages reserves							512,000,000	512,000,000	512,000,000	$ 536,000,000
Reinsurance retention policy, excess retention, amount reinsured									814,000,000
Probable insurance recoveries							$ 587,000,000	$ 587,000,000	$ 587,000,000	599,000,000
Duke Energy Carolinas [Member] | Asbestos Issue [Member] | Non Malignant Asbestos Claim [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, pending claims, number | Claims							121	121	121
Asbestos-related injuries and damages reserves							$ 32,000,000	$ 32,000,000	$ 32,000,000
Duke Energy Carolinas [Member] | Asbestos Issue [Member] | Malignant Asbestos Claim [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, pending claims, number | Claims							58	58	58
Asbestos-related injuries and damages reserves							$ 16,000,000	$ 16,000,000	$ 16,000,000
Duke Energy Progress [Member]
Insurance [Abstract]
Primary nuclear liability program coverage							375,000,000	375,000,000	375,000,000
Primary Nuclear Liability Coverage after January 2017									450,000,000
Max Retroactive Premium Assessments									104,000,000
Duke Energy Progress [Member] | Robinson Nuclear Station [Member]
Insurance [Abstract]
Sublimit property damage losses							1,500,000,000	1,500,000,000	1,500,000,000
Additional nuclear accident limit							1,250,000,000	1,250,000,000	1,250,000,000
Accidental outage insurance coverage policy limit							404,000,000	404,000,000	404,000,000
Duke Energy Progress [Member] | Brunswick Nuclear Station [Member]
Insurance [Abstract]
Sublimit property damage losses							1,500,000,000	1,500,000,000	1,500,000,000
Additional nuclear accident limit							1,250,000,000	1,250,000,000	1,250,000,000
Accidental outage insurance coverage policy limit							490,000,000	490,000,000	490,000,000
Duke Energy Progress [Member] | Shearon Harris Nuclear Station [Member]
Insurance [Abstract]
Sublimit property damage losses							1,500,000,000	1,500,000,000	1,500,000,000
Additional nuclear accident limit							1,250,000,000	1,250,000,000	1,250,000,000
Accidental outage insurance coverage policy limit							490,000,000	490,000,000	490,000,000
Duke Energy Progress [Member] | North Carolina Ash Basins [Member] | USDOJ [Member]
Valuation and Qualifying Accounts [Abstract]
Minimum Master Credit Facility Balance required							250,000,000	250,000,000	250,000,000
Duke Energy Progress [Member] | North Carolina Ash Basins [Member] | Operating Expense [Member] | USDOJ [Member]
Valuation and Qualifying Accounts [Abstract]
Litigation Settlement, Expense											$ 30,000,000
Duke Energy Progress [Member] | Groundwater Violation [Member]
Valuation and Qualifying Accounts [Abstract]
Charge for settlement agreement									6,000,000
Duke Energy Progress [Member] | Groundwater Violation [Member] | L V Sutton Plant [Member]
Valuation and Qualifying Accounts [Abstract]
Civil Penalty Assessed					$ 25,000,000
Duke Energy Progress [Member] | Potential Groundwater Claims [Member]
Valuation and Qualifying Accounts [Abstract]
Settlement Offer Expense							4,000,000
Duke Energy Progress [Member] | Spent Nuclear Fuels [Member]
Valuation and Qualifying Accounts [Abstract]
Gain contingency, unrecorded amount							48,000,000	48,000,000	48,000,000
Duke Energy Florida [Member]
Insurance [Abstract]
Primary nuclear liability program coverage							375,000,000	375,000,000	375,000,000
Primary Nuclear Liability Coverage after January 2017									450,000,000
Max Retroactive Premium Assessments									1,000,000
Duke Energy Florida [Member] | Crystal River Unit 3 [Member]
Insurance [Abstract]
Sublimit property damage losses							$ 50,000,000	$ 50,000,000	$ 50,000,000
Potential Obligation percentage							100.00%	100.00%	100.00%
Duke Energy Florida [Member] | Spent Nuclear Fuels [Member]
Valuation and Qualifying Accounts [Abstract]
Gain contingency, unrecorded amount							$ 25,000,000	$ 25,000,000	$ 25,000,000
Duke Energy Florida [Member] | Westinghouse Electric Company Litigation [Member]
Valuation and Qualifying Accounts [Abstract]
Gain contingency, unrecorded amount							54,000,000	54,000,000	54,000,000
Loss Contingency, Damages Sought, Original Amount							482,000,000	482,000,000	482,000,000				$ 510,000,000
Loss Contingency, Damages Awarded, Value	$ 30,000,000								30,000,000
Gain Contingency, Dismissed Amount	$ 54,000,000
Loss contingency, damages sought, value									424,000,000
Loss Contingency Damages Awarded and Interest, Value							$ 34,000,000
Duke Energy Florida [Member] | MGP Cost Recovery Action [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, damages sought, value									43,000,000
Duke Energy Ohio [Member] | Antitrust Lawsuit [Member]
Valuation and Qualifying Accounts [Abstract]
Litigation Settlement, Amount										81,000,000
Litigation Settlement, Expense										$ 81,000,000
Duke Energy Ohio [Member] | W.C. Beckjord Fuel Release [Member] | W.C. Beckjord Station [Member]
Valuation and Qualifying Accounts [Abstract]
Gallons of Fuel Released | gal												9,000
Environmental Fine								1,000,000
Required Charitable Contribution								$ 100,000
Remediation Expense Reimbursed									1,000,000
Duke Energy Indiana [Member] | Benton County Wind Farm Dispute [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, damages sought, value									$ 16,000,000