Regulatory Matters (Regulatory Matters Narrative - Duke Energy Carolinas) (Details) $ in Millions						3 Months Ended		4 Months Ended	12 Months Ended							24 Months Ended
	Mar. 14, 2024 USD ($) numberOfCombustionTurbines MW	Jan. 04, 2024 USD ($)	Dec. 15, 2023	Aug. 22, 2023 USD ($)	Jan. 19, 2023	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2026 USD ($)	Dec. 14, 2027 USD ($)	Dec. 14, 2026 USD ($)	Aug. 31, 2026 USD ($)	Dec. 14, 2025 USD ($)	Aug. 31, 2025 USD ($)	Dec. 14, 2024 USD ($)	Aug. 31, 2024 USD ($)	Jan. 03, 2028 USD ($)	Jan. 03, 2026 USD ($)
Public Utilities, General Disclosures [Line Items]
Impairment of assets and other charges						$ 1	$ 8
Operation, maintenance and other						1,379	1,310
Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Impairment of assets and other charges						1	2
Operation, maintenance and other						$ 451	$ 440
2023 North Carolina Rate Case | NCUC | Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Proposed rate period (in years)					3 years
Settlement rate, amount				$ 19,500
Settlement rate, period (in years)				3 years
Approved return on equity percentage (as a percent)			10.10%
2023 North Carolina Rate Case | NCUC | Duke Energy Carolinas | Equity
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage (as a percent)			53.00%
2023 North Carolina Rate Case | NCUC | Duke Energy Carolinas | Forecast
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount								$ 823			$ 150		$ 172		$ 501
Requested rate increase (decrease) (as a percent)								15.70%
Approved rate increase (decrease), amount									$ 768	$ 158		$ 174		$ 436
2023 North Carolina Rate Case, Retail Allocated | NCUC | Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Settlement rate, amount				$ 4,600
2024 South Carolina Rate Case | PSCSC | Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount		$ 323
Requested rate increase (decrease) (as a percent)		15.50%
Requested return on equity (as a percent)		10.50%
2024 South Carolina Rate Case | PSCSC | Duke Energy Carolinas | Equity
Public Utilities, General Disclosures [Line Items]
Equity ratio (as a percent)		53.00%
2024 South Carolina Rate Case | PSCSC | Duke Energy Carolinas | Forecast
Public Utilities, General Disclosures [Line Items]
Requested rate increase, percentage, net of tax																4.10%	11.40%
Requested rate increase (decrease), amended amount																$ 84	$ 239
Marshall Combustion Turbines CPCN Proceedings | NCUC | Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount	$ 104
Requested rate increase (decrease) (as a percent)	2.20%
New combustion turbines (in megawatts) | MW	850
Hydrogen-capable CTs | numberOfCombustionTurbines	2