Regulatory Matters (Regulatory Matters Narrative - Duke Energy Progress) (Details) - Duke Energy Progress $ in Millions	Oct. 26, 2020 USD ($)	Oct. 16, 2020	Jul. 31, 2020 USD ($)	Jun. 17, 2020 USD ($)	Jan. 29, 2020 USD ($) MW	Oct. 30, 2019 USD ($)	Oct. 11, 2019	May 21, 2019 USD ($)	Nov. 08, 2018 USD ($)	Nov. 22, 2017	Jun. 01, 2017 USD ($)	Sep. 30, 2020 USD ($)	Jul. 27, 2020 MW	Jul. 01, 2020 USD ($)	Feb. 07, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)
2017 North Carolina Rate Case | NCUC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount											$ 477
Requested rate increase (decrease), amended amount											$ 420
Requested return on equity, percent										9.90%
Public utilities, requested equity capital structure, percentage										52.00%
Public utilities, requested debt capital structure, percentage										48.00%
2019 North Carolina Rate Case | NCUC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount						$ 464
Requested rate increase, percentage						12.30%
Requested rate increase (decrease), gross amount						$ 586
Rider reduction						122
Requested rate increase (decrease), rider reduction						$ 120
2019 North Carolina Rate Case, additional Agreement and Stipulation of Partial Settlement | NCUC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amended amount			$ 500
Requested return on equity, percent			9.60%
Public utilities, requested equity capital structure, percentage			52.00%
Public utilities, requested debt capital structure, percentage			48.00%
Regulatory asset, amortization period			5 years
Annual revenue requirement | NCUC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amended amount			$ 25
Annual revenue requirement | Subsequent event | NCUC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amended amount	$ 842
Hurricane Dorian storm damage
Public Utilities, General Disclosures [Line Items]
Estimated storm costs - O&M																	$ 168
Estimated storm costs - capital investments																	$ 4
Hurricane Dorian storm damage | PSCSC
Public Utilities, General Disclosures [Line Items]
Storm deferral - O&M															$ 22
Requested supplemental true-up														$ 17
Hurricane Dorian storm damage | Storm costs
Public Utilities, General Disclosures [Line Items]
Regulatory assets												$ 145				$ 179
South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount									$ 59
Approved return on equity percentage								9.50%
Public utilities, approved equity capital structure, percentage								53.00%
Public utilities, approved debt capital structure, percentage								47.00%
Change in tax rate, deferred tax liability, income tax benefit								$ 17
Measurement period adjustment, income tax expense (benefit)								12
South Carolina Rate Case 2018 | State and local jurisdiction | North Carolina Department of Revenue | PSCSC
Public Utilities, General Disclosures [Line Items]
State and local taxes increase amount								12
South Carolina Rate Case 2018 | Asset retirement obligations - coal ash | PSCSC
Public Utilities, General Disclosures [Line Items]
Regulatory assets								4
Recovery costs denied								$ 65
Regulatory asset, amortization period								5 years
South Carolina Rate Case 2018 | Asset retirement obligations - unprotected EDIT, Property, Plant and Equipment | PSCSC
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period								20 years
South Carolina Rate Case 2018 | Asset retirement obligations - unprotected EDIT | PSCSC
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period								5 years
South Carolina Rate Case 2018 | Asset retirement obligations - deferred revenue | PSCSC
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period								3 years
Western Carolinas Modernization Plan
Public Utilities, General Disclosures [Line Items]
Generation capacity (MW) | MW													5
Western Carolinas Modernization Plan | Asheville Plant
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW					376
Generation facilities retired, net					$ 214
Western Carolinas Modernization Plan | Depreciation expense, property taxes, incremental O&M and carrying costs | PSCSC
Public Utilities, General Disclosures [Line Items]
Approved annual rate increase (decrease), amount				$ 8
FERC Return on Equity Complaint, NCEMPA | FERC
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage							11.00%
FERC Return on Equity Complaint, NCEMC | Subsequent event | FERC
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage		11.00%