Derivatives and Hedging (Notional Amounts of Derivative Instruments) (Details) Mcf in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) GWh shares Mcf	Dec. 31, 2018 USD ($) GWh Mcf
Call options
Derivative [Line Items]
Aggregate notional amount | shares	305,000
Put options
Derivative [Line Items]
Aggregate notional amount | shares	305,000
Interest Rate Contracts
Derivative [Line Items]
Notional Amount	$ 2,270	$ 2,644
Interest Rate Contracts | Designated contracts
Derivative [Line Items]
Notional Amount	993	923
Interest Rate Contracts | Undesignated contracts
Derivative [Line Items]
Notional Amount	$ 1,277	$ 1,721
Commodity contracts | Electricity (GWh)
Derivative [Line Items]
Notional amount, energy measure, in gigawatt-hours | GWh	15,858	15,286
Commodity contracts | Natural gas (millions of Dth)
Derivative [Line Items]
Notional amount, volume in millions of decatherms | Mcf	704	739
VIE | Interest Rate Contracts | Designated contracts
Derivative [Line Items]
Notional Amount	$ 693	$ 422
VIE | Interest Rate Contracts | Undesignated contracts
Derivative [Line Items]
Notional Amount		194
Duke Energy Carolinas | Interest Rate Contracts
Derivative [Line Items]
Notional Amount	450	300
Duke Energy Carolinas | Interest Rate Contracts | Designated contracts
Derivative [Line Items]
Notional Amount	0	0
Duke Energy Carolinas | Interest Rate Contracts | Undesignated contracts
Derivative [Line Items]
Notional Amount	$ 450	$ 300
Duke Energy Carolinas | Commodity contracts | Natural gas (millions of Dth)
Derivative [Line Items]
Notional amount, volume in millions of decatherms | Mcf	130	121
Progress Energy | Interest Rate Contracts
Derivative [Line Items]
Notional Amount	$ 800	$ 1,200
Progress Energy | Interest Rate Contracts | Designated contracts
Derivative [Line Items]
Notional Amount	0	0
Progress Energy | Interest Rate Contracts | Undesignated contracts
Derivative [Line Items]
Notional Amount	$ 800	$ 1,200
Progress Energy | Commodity contracts | Natural gas (millions of Dth)
Derivative [Line Items]
Notional amount, volume in millions of decatherms | Mcf	160	169
Duke Energy Progress | Interest Rate Contracts
Derivative [Line Items]
Notional Amount	$ 250	$ 650
Duke Energy Progress | Interest Rate Contracts | Designated contracts
Derivative [Line Items]
Notional Amount	0	0
Duke Energy Progress | Interest Rate Contracts | Undesignated contracts
Derivative [Line Items]
Notional Amount	$ 250	$ 650
Duke Energy Progress | Commodity contracts | Natural gas (millions of Dth)
Derivative [Line Items]
Notional amount, volume in millions of decatherms | Mcf	160	166
Duke Energy Florida | Interest Rate Contracts
Derivative [Line Items]
Notional Amount	$ 550	$ 550
Duke Energy Florida | Interest Rate Contracts | Designated contracts
Derivative [Line Items]
Notional Amount	0	0
Duke Energy Florida | Interest Rate Contracts | Undesignated contracts
Derivative [Line Items]
Notional Amount	550	$ 550
Duke Energy Florida | Commodity contracts | Natural gas (millions of Dth)
Derivative [Line Items]
Notional amount, volume in millions of decatherms | Mcf		3
Duke Energy Ohio | Interest Rate Contracts
Derivative [Line Items]
Notional Amount	27	$ 27
Duke Energy Ohio | Interest Rate Contracts | Designated contracts
Derivative [Line Items]
Notional Amount	0	0
Duke Energy Ohio | Interest Rate Contracts | Undesignated contracts
Derivative [Line Items]
Notional Amount	$ 27	$ 27
Duke Energy Ohio | Commodity contracts | Electricity (GWh)
Derivative [Line Items]
Notional amount, energy measure, in gigawatt-hours | GWh	1,887	1,786
Duke Energy Indiana | Commodity contracts | Electricity (GWh)
Derivative [Line Items]
Notional amount, energy measure, in gigawatt-hours | GWh	13,971	13,500
Duke Energy Indiana | Commodity contracts | Natural gas (millions of Dth)
Derivative [Line Items]
Notional amount, volume in millions of decatherms | Mcf	3	1
Piedmont | Commodity contracts | Natural gas (millions of Dth)
Derivative [Line Items]
Notional amount, volume in millions of decatherms | Mcf	411	448