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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 |

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