Commitments and Contingencies (Narrative) (Details)	1 Months Ended	2 Months Ended	12 Months Ended
	Jul. 31, 2018 USD ($)	Feb. 28, 2019 USD ($)	Dec. 31, 2018 USD ($) plant reactor claim T	Dec. 31, 2017 USD ($)	Mar. 31, 2014 USD ($)
Insurance [Abstract]
Insured public liability limit per nuclear incident			$ 14,100,000,000
Excess nuclear liability program coverage			13,600,000,000
Pro rata assessment for each reactor owned for each incident exceeding public liability insurance			$ 138,000,000
Number of licensed nuclear reactors | reactor			99
Annual payment limit to pro rata assessments			$ 20,500,000
Industry aggregate limit			3,200,000,000
Sublimit for non-nuclear terrorist events			$ 1,800,000,000
Insurance Coverage Percentage Initial Weeks			100.00%
Accidental Outage Insurance Coverage Initial Weeks			365 days
Insurance Coverage Percentage Additional Weeks			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
Maximum Magnitude of Retroactive Premiums			10
Maximum Period for Retroactive Premium Assessment			6 years
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Reserves for legal matters			$ 65,000,000	$ 88,000,000
Coal Ash Insurance Coverage Litigation [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Number of NC and SC Plants with Ash Basins | plant			15
NCDEQ State Enforcement Actions [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Facilities with Ash Basins | plant			14
Number of Plants with No Disputed Facts | plant			7
Number of Plants with Disputed Facts | plant			7
Groundwater Contamination Claims [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Goodwill Payment			$ 5,000
Water Bill Stipend Period			25 years
Duke Energy Carolinas [Member]
Insurance [Abstract]
Primary nuclear liability program coverage			$ 450,000,000
Max Retroactive Premium Assessments			159,000,000
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Reserves for legal matters			9,000,000	30,000,000
Duke Energy Carolinas [Member] | McGuire Nuclear Station [Member]
Insurance [Abstract]
Accidental outage insurance coverage policy limit			490,000,000
Duke Energy Carolinas [Member] | Catawba Nuclear Station [Member]
Insurance [Abstract]
Dedicated additional nuclear accident limit			1,250,000,000
Additional Non Nuclear Accident Limit			750,000,000
Accidental outage insurance coverage policy limit			$ 490,000,000
Potential Obligation percentage			100.00%
Duke Energy Carolinas [Member] | Oconee Nuclear Station [Member]
Insurance [Abstract]
Additional nuclear accident limit			$ 1,250,000,000
Additional Non Nuclear Accident Limit			750,000,000
Accidental outage insurance coverage policy limit			462,000,000
Duke Energy Carolinas [Member] | Harris Nuclear Plant [Member]
Insurance [Abstract]
Accidental outage insurance coverage policy limit			490,000,000
Duke Energy Carolinas [Member] | Asbestos Issue [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Asbestos-related injuries and damages reserves			630,000,000	489,000,000
Reinsurance retention policy, excess retention, amount reinsured			764,000,000
Loss contingency, receivable, noncurrent			$ 739,000,000	585,000,000
Duke Energy Carolinas [Member] | Asbestos Issue [Member] | Non Malignant Asbestos Claim [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Loss contingency, pending claims, number | claim			164
Asbestos-related injuries and damages reserves			$ 42,000,000
Duke Energy Carolinas [Member] | Asbestos Issue [Member] | Malignant Asbestos Claim [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Loss contingency, pending claims, number | claim			87
Asbestos-related injuries and damages reserves			$ 21,000,000
Progress Energy [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Reserves for legal matters			54,000,000	55,000,000
Duke Energy Progress [Member]
Insurance [Abstract]
Primary nuclear liability program coverage			450,000,000
Max Retroactive Premium Assessments			97,000,000
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Reserves for legal matters			12,000,000	13,000,000
Duke Energy Progress [Member] | Robinson Nuclear Station [Member]
Insurance [Abstract]
Sublimit property damage losses			1,500,000,000
Accidental outage insurance coverage policy limit			392,000,000
Duke Energy Progress [Member] | Brunswick Nuclear Station [Member]
Insurance [Abstract]
Accidental outage insurance coverage policy limit			476,000,000
Duke Energy Progress [Member] | Spent Nuclear Fuels [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Gain contingency, unrecorded amount			48,000,000
Litigation settlement, amount award from other party			$ 48,000,000
Duke Energy Progress [Member] | Gypsum Supply Agreements [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Minimum Amount of Gypsum To Be Supplied | T			50,000
Estimate of possible losses			$ 90,000,000
Settlement period			10 years
Loss contingency, damages paid, value			$ 3,000,000
Duke Energy Florida [Member]
Insurance [Abstract]
Primary nuclear liability program coverage			100,000,000
Max Retroactive Premium Assessments			1,000,000
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Reserves for legal matters			24,000,000	24,000,000
Duke Energy Florida [Member] | Crystal River Unit 3 [Member]
Insurance [Abstract]
Sublimit property damage losses			50,000,000
Duke Energy Florida [Member] | Spent Nuclear Fuels [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Gain contingency, unrecorded amount			25,000,000
Litigation settlement, amount award from other party			21,000,000
Duke Energy Florida [Member] | Westinghouse Electric Company Litigation [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Gain contingency, unrecorded amount			54,000,000
Damages sough, original amount					$ 510,000,000
Damages awarded, value			30,000,000
Gain contingency, dismissed amount			54,000,000
Loss contingency, damages awarded and interest, value			34,000,000
Loss contingency, damages paid, value	$ 34,000,000
Duke Energy Florida [Member] | MGP Cost Recovery Action [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Loss contingency, damages sought, value			43,000,000
Piedmont Natural Gas [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Reserves for legal matters			1,000,000	$ 2,000,000
Accounts Payable [Member] | Duke Energy Progress [Member] | Gypsum Supply Agreements [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Reserves for legal matters			9,000,000
Other Noncurrent Liabilities [Member] | Duke Energy Progress [Member] | Gypsum Supply Agreements [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Reserves for legal matters			$ 63,000,000
Measurement Input, Discount Rate [Member] | Duke Energy Progress [Member] | Gypsum Supply Agreements [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Loss contingency, measurement input			0.04
Subsequent Event [Member] | Duke Energy Florida [Member] | Fluor Contract Litigation [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Loss contingency, damages sought, value		$ 110,000,000
Fluor Letter Of Credit [Member] | Subsequent Event [Member] | Duke Energy Florida [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Drawings on credit facility		$ 67,000,000