Regulatory Matters (Duke Energy Progress Narrative) (Details) $ in Millions															3 Months Ended	12 Months Ended
	Oct. 26, 2020 USD ($)	Oct. 16, 2020	Jul. 31, 2020 USD ($)	Jun. 17, 2020 USD ($)	Oct. 30, 2019 USD ($)	Oct. 11, 2019	Sep. 30, 2019 USD ($)	May 21, 2019 USD ($)	Nov. 08, 2018 USD ($)	Jun. 22, 2018 USD ($)	Feb. 28, 2018	Nov. 22, 2017	Aug. 25, 2017 USD ($)	Jun. 01, 2017 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jul. 27, 2020 MW	Jul. 01, 2020 USD ($)	Feb. 07, 2020 USD ($)	Jan. 29, 2020 USD ($) MW
Public Utilities, General Disclosures [Line Items]
Impairment charges																$ 984	$ (8)	$ 402
Regulatory assets																14,062	15,018
Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Impairment charges																499	12	33
Regulatory assets																4,468	4,678
Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Impairment charges																476	17	$ 192
Regulatory assets																3,469	3,910
North Carolina Utilities Commission | Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amended, amount	$ 920
North Carolina Utilities Commission | Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amended, amount	$ 287
2017 North Carolina Rate Case | NCUC | Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease)														$ 477
Requested rate increase (decrease), amended, amount														$ 420
Requested return on equity, percentage												9.90%
Requested capital structure, percentage												52.00%
Requested debt structure, percentage												48.00%
Impairment charges															$ 68
2017 North Carolina Rate Case | NCUC | Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease)													$ 647
Requested return on equity, percentage											9.90%
Requested capital structure, percentage											52.00%
Requested debt structure, percentage											48.00%
Impairment charges										$ 150					$ 14
2019 North Carolina Rate Case | NCUC | Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease)					$ 464
Requested rate increase (decrease), percent					12.30%
Requested gross rate case revenue increase					$ 586
Requested rate increase (decrease), rider reduction, tax cuts and jobs act and return deferred revenue					122
Requested EDIT rider decrease					$ 120
2019 North Carolina Rate Case | NCUC | Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease)							$ 291
Requested rate increase (decrease), percent							6.00%
Requested gross rate case revenue increase							$ 445
Requested EDIT rider decrease							154
2019 North Carolina Rate Case, Additional Agreement and Stipulation of Partial Settlement | North Carolina Utilities Commission | Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amended, amount			$ 500
Requested return on equity, percentage			9.60%
Requested capital structure, percentage			52.00%
Requested debt structure, percentage			48.00%
2019 North Carolina Rate Case, Additional Agreement and Stipulation of Partial Settlement | North Carolina Utilities Commission | Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amended, amount			$ 800
Requested return on equity, percentage			9.60%
Requested capital structure, percentage			52.00%
Requested debt structure, percentage			48.00%
Hurricane Dorian Storm Damage | Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Estimated storm costs - operation maintenance							168
Estimated storm costs - capital investments							$ 4
Hurricane Dorian Storm Damage | PSCSC | Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Storm deferral - operation maintenance																					$ 22
Storm deferral - requested supplemental true-up																				$ 17
2018 South Carolina Rate Case | PSCSC | Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease)									$ 59
Approved return on equity, percentage								9.50%
Approved capital structure, percentage								53.00%
Approved debt structure, percentage								47.00%
Tax benefit from change in enacted tax rates								$ (17)
Measurement period adjustment								$ (12)
2018 South Carolina Rate Case | PSCSC | Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease)									$ 168
Approved return on equity, percentage								9.50%
Approved capital structure, percentage								53.00%
Approved debt structure, percentage								47.00%
Tax benefit from change in enacted tax rates								$ (66)
Measurement period adjustment								(45)
Western Carolinas Modernization Plan | Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Solar generation capacity plants (in MW) | MW																			5
FERC Return on Equity Complaint, North Carolina Eastern Municipal Power Agency | FERC | Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Approved return on equity, percentage						11.00%
FERC Return on Equity Complaint, North Carolina Electric Membership Corporation | FERC | Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Approved return on equity, percentage		11.00%
2019 North Carolina Rate Case, Additional Agreement and Stipulation of Partial Settlement, Estimated Annual Revenue Requirement | North Carolina Utilities Commission | Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amended, amount			$ 25
2019 North Carolina Rate Case, Additional Agreement and Stipulation of Partial Settlement, Estimated Annual Revenue Requirement | North Carolina Utilities Commission | Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amended, amount			$ 45
Storm cost deferrals
Public Utilities, General Disclosures [Line Items]
Regulatory assets																1,102	1,399
Storm cost deferrals | Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Regulatory assets																785	801
Storm cost deferrals | Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Regulatory assets																205	178
Storm cost deferrals | Hurricane Dorian Storm Damage | Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Regulatory assets																145	179
AROs – coal ash
Public Utilities, General Disclosures [Line Items]
Regulatory assets																3,408	4,084
AROs – coal ash | Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Regulatory assets																1,347	1,834
AROs – coal ash | Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Regulatory assets																$ 1,414	$ 1,696
AROs – coal ash | 2018 South Carolina Rate Case | PSCSC | Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Regulatory assets								4
Denied recovery costs								65
AROs – coal ash | 2018 South Carolina Rate Case | PSCSC | Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Regulatory assets								96
Denied recovery costs								115
Ashville Depreciation Expense, Property Taxes, Incremental O&M and Carrying Costs | Western Carolinas Modernization Plan | PSCSC | Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Public utilities, approved annual rate increase (decrease), amount				$ 8
State | North Carolina DOR | 2018 South Carolina Rate Case | PSCSC | Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Approved increase (decrease) through EDIT Rider								12
State | North Carolina DOR | 2018 South Carolina Rate Case | PSCSC | Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Approved increase (decrease) through EDIT Rider								$ (17)
Asheville Plant | Western Carolinas Modernization Plan | Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Capacity of retired plant | MW																						376
Generation facilities retired net																						$ 214