Regulatory Matters (Regulatory Matters Narrative - Duke Energy Ohio) (Details) - Duke Energy Ohio - USD ($) $ in Millions	Apr. 01, 2024	Oct. 12, 2023	Apr. 28, 2023	Dec. 01, 2022	Sep. 19, 2022	Jul. 14, 2022	Oct. 01, 2021
Duke Energy Ohio Electric Base Rate Case | PUCO
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount					$ 23		$ 55
Requested return on equity (as a percent)					9.50%
Equity ratio (as a percent)					50.50%
Duke Energy Ohio Gas Base Rate Case | PUCO
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount			$ 32			$ 49
Requested return on equity (as a percent)			9.60%
Duke Energy Ohio Gas Base Rate Case | PUCO | Maximum
Public Utilities, General Disclosures [Line Items]
Equity ratio (as a percent)			52.32%
Duke Energy Kentucky Electric Base Rate Case | KPSC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount				$ 75
Approved rate increase (decrease), amount		$ 48
Duke Energy Kentucky Electric Base Rate Case | KPSC | Maximum
Public Utilities, General Disclosures [Line Items]
Equity ratio (as a percent)		52.145%
Duke Energy Kentucky Electric Base Rate Case, Electric Riders | KPSC
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage (as a percent)		9.65%
Duke Energy Kentucky Electric Base Rate Case, Electric Base Rates | KPSC
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage (as a percent)		9.75%
Duke Energy Ohio Energy Security Plan | PUCO | Subsequent event
Public Utilities, General Disclosures [Line Items]
Settlement rate, period (in years)	3 years