Regulatory Matters (Regulatory Matters Narrative - Duke Energy Progress) (Details) - Duke Energy Progress customer in Thousands, $ in Millions							3 Months Ended
	Jan. 29, 2020 USD ($) MW	Oct. 30, 2019 USD ($)	May 21, 2019 USD ($)	Nov. 08, 2018 USD ($)	Nov. 22, 2017	Jun. 01, 2017 USD ($)	Mar. 31, 2020 USD ($)	Feb. 07, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($) customer	Mar. 28, 2016 USD ($)
2017 North Carolina Rate Case | NCUC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount						$ 477
Requested rate increase, percentage						14.90%
Requested rate increase (decrease), amended amount						$ 420
Requested rate increase (decrease) amended, percentage						13.00%
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
Hurricane Dorian storm damage
Public Utilities, General Disclosures [Line Items]
Estimated storm costs - O&M										$ 177
Estimated storm costs - capital investments										$ 4
Storm deferral - O&M								$ 22
South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount				$ 59
Requested rate increase, percentage				10.30%
Change in tax rate, deferred tax liability, income tax benefit			$ 17	$ 17
Measurement period adjustment, income tax expense (benefit)			$ 12	10
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%
Western Carolinas Modernization Plan | NCUC
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period							10 years
Estimated capital cost											$ 893
NORTH CAROLINA | Hurricane Dorian storm damage
Public Utilities, General Disclosures [Line Items]
Customers experiencing outages | customer										270
SOUTH CAROLINA | Hurricane Dorian storm damage
Public Utilities, General Disclosures [Line Items]
Customers experiencing outages | customer										30
Storm Costs [Member] | Hurricane Dorian storm damage
Public Utilities, General Disclosures [Line Items]
Regulatory assets							$ 151		$ 179
Asset retirement obligations - coal ash | South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
Regulatory assets			$ 4	$ 51
Recovery costs denied			$ 65
Regulatory asset, amortization period			5 years	5 years
Asset retirement obligations - unprotected EDIT, Property, Plant and Equipment | South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period			20 years
Asset retirement obligations - unprotected EDIT | South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period			5 years
Asset retirement obligations - deferred revenue | South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period			3 years
State and local jurisdiction | North Carolina Department of Revenue | South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
State and local taxes reduction amount			$ (12)	$ (12)
Asheville Plant
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	376
Generation facilities retired, net	$ 214