Regulatory Matters (Regulatory Matters Narrative - Duke Energy Carolinas) (Details) - Duke Energy Carolinas - USD ($) $ in Millions			4 Months Ended	12 Months Ended
	May 31, 2023	Jan. 19, 2023	Dec. 31, 2026	Aug. 31, 2026	Aug. 31, 2025	Aug. 31, 2024
2023 North Carolina Rate Case | NCUC
Public Utilities, General Disclosures [Line Items]
Proposed rate period (in years)		3 years
2023 South Carolina Storm Securitization
Public Utilities, General Disclosures [Line Items]
Storm costs	$ 171
Forecast | 2023 North Carolina Rate Case | NCUC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount			$ 823	$ 150	$ 172
Requested return on equity (as a percent)			15.70%
Forecast | 2023 North Carolina Rate Case | NCUC | Subsequent event
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount						$ 501