Commitments and Contingencies (Narrative) (Details) $ in Millions		12 Months Ended
	Jun. 18, 2018 USD ($)	Dec. 31, 2020 USD ($) reactor claim plant	Dec. 31, 2019 USD ($)
Insurance [Abstract]
Number of licensed nuclear reactors | reactor		97
Insured public liability limit per nuclear incident		$ 13,800.0
Excess nuclear liability program coverage		13,300.0
Pro rata assessment for each reactor owned for each incident exceeding public liability insurance		138.0
Annual payment limit to pro rata assessments		20.5
Industry aggregate limit		3,200.0
Sublimit for non-nuclear terrorist events		1,800.0
Sublimit property damage losses		1,500.0
Additional nuclear accident limit		$ 1,250.0
Accidental outage insurance coverage initial weeks		365 days
Accidental outage insurance coverage additional weeks		770 days
Weeks of sublimits for accidental outage coverage		728 days
Insurance coverage percentage initial weeks		100.00%
Insurance coverage percentage additional weeks		80.00%
Sublimit accidental outage recovery		$ 328.0
Maximum magnitude of retroactive premiums		10
Maximum period for retroactive premium assessment		6 years
Coal Ash Insurance Coverage Litigation
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Number of NC and SC plants with ash basins | plant		15
Duke Energy Carolinas
Insurance [Abstract]
Primary nuclear liability program coverage		$ 450.0
Max retroactive premium assessments		156.0
Duke Energy Carolinas | Asbestos Issue
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Asbestos-related injuries and damages reserves		572.0	$ 604.0
Reinsurance retention policy, excess retention, amount reinsured		714.0
Loss contingency, receivable, noncurrent		$ 704.0	$ 742.0
Duke Energy Carolinas | Asbestos Issue | Non Malignant Asbestos Claim
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Loss contingency, pending claims, number | claim		145
Asbestos-related injuries and damages reserves		$ 39.0
Duke Energy Carolinas | Asbestos Issue | Malignant Asbestos Claim
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Loss contingency, pending claims, number | claim		56
Asbestos-related injuries and damages reserves		$ 20.0
Duke Energy Carolinas | McGuire
Insurance [Abstract]
Number of licensed nuclear reactors | reactor		2
Accidental outage insurance coverage policy limit		$ 490.0
Duke Energy Carolinas | Catawba
Insurance [Abstract]
Number of licensed nuclear reactors | reactor		2
Dedicated additional nuclear accident limit		$ 1,250.0
Additional Non-nuclear accident limit		750.0
Accidental outage insurance coverage policy limit		$ 490.0
Potential obligation percentage		100.00%
Duke Energy Carolinas | Oconee
Insurance [Abstract]
Number of licensed nuclear reactors | reactor		3
Additional Non-nuclear accident limit		$ 750.0
Accidental outage insurance coverage policy limit		392.0
Duke Energy Progress
Insurance [Abstract]
Primary nuclear liability program coverage		450.0
Max retroactive premium assessments		$ 93.0
Duke Energy Progress | Spent Nuclear Fuel Matters
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Damages sought	$ 100.0
Duke Energy Progress | Robinson
Insurance [Abstract]
Number of licensed nuclear reactors | reactor		1
Accidental outage insurance coverage policy limit		$ 336.0
Duke Energy Progress | Harris
Insurance [Abstract]
Number of licensed nuclear reactors | reactor		1
Accidental outage insurance coverage policy limit		$ 434.0
Duke Energy Progress | Brunswick
Insurance [Abstract]
Number of licensed nuclear reactors | reactor		2
Accidental outage insurance coverage policy limit		$ 420.0
Duke Energy Florida
Insurance [Abstract]
Primary nuclear liability program coverage		100.0
Max retroactive premium assessments		1.0
Duke Energy Florida | Spent Nuclear Fuel Matters
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Damages sought	$ 200.0
Duke Energy Florida | Crystal River Unit 3
Insurance [Abstract]
Sublimit property damage losses		50.0
Duke Energy and Duke Energy Carolinas | ASU 2016-13
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Premium receivable, allowance for credit loss		$ 15.0