Regulatory Matters (Regulatory Matters Narrative - Duke Energy Progress) (Details) - Duke Energy Progress $ in Millions	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 ($)	Jul. 01, 2020 USD ($)	Jun. 30, 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 | Subsequent event | 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 | Subsequent event | NCUC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amended amount	$ 25
Request withdraw | Subsequent event | NCUC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amended amount	$ 500
Hurricane Dorian storm damage
Public Utilities, General Disclosures [Line Items]
Estimated storm costs - O&M														$ 165
Estimated storm costs - capital investments														$ 4
Hurricane Dorian storm damage | PSCSC
Public Utilities, General Disclosures [Line Items]
Storm deferral - O&M												$ 22
Hurricane Dorian storm damage | Subsequent event | PSCSC
Public Utilities, General Disclosures [Line Items]
Requested supplemental true-up										$ 17
Hurricane Dorian storm damage | Storm costs
Public Utilities, General Disclosures [Line Items]
Regulatory assets											$ 139		$ 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 | 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 | FERC
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage					11.00%