Derivatives and Hedging (Notional Amounts of Derivative Instruments) (Details) Mcf in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) GWh Mcf	Dec. 31, 2019 USD ($) GWh Mcf
Interest Rate Contracts
Derivative [Line Items]
Notional Amount	$ 1,809	$ 2,270
Interest Rate Contracts | Designated contracts | Cash flow hedges
Derivative [Line Items]
Notional Amount	632	993
Interest Rate Contracts | Undesignated contracts
Derivative [Line Items]
Notional Amount	$ 1,177	$ 1,277
Commodity contracts | Electricity (GWh)(a)
Derivative [Line Items]
Notional amount, energy measure, in gigawatt-hours | GWh	35,409	15,858
Commodity contracts | Electricity (GWh)(a) | Cash flow hedges
Derivative [Line Items]
Notional amount, energy measure, in gigawatt-hours | GWh	22,048
Commodity contracts | Natural gas (millions of Dth)
Derivative [Line Items]
Notional amount, volume in millions of decatherms | Mcf	678	704
Consolidated VIEs | Interest Rate Contracts | Designated contracts | Cash flow hedges
Derivative [Line Items]
Notional Amount	$ 632	$ 693
Duke Energy Carolinas | Interest Rate Contracts
Derivative [Line Items]
Notional Amount	400	450
Duke Energy Carolinas | Interest Rate Contracts | Undesignated contracts
Derivative [Line Items]
Notional Amount	$ 400	$ 450
Duke Energy Carolinas | Commodity contracts | Natural gas (millions of Dth)
Derivative [Line Items]
Notional amount, volume in millions of decatherms | Mcf	145	130
Progress Energy | Interest Rate Contracts
Derivative [Line Items]
Notional Amount	$ 750	$ 800
Progress Energy | Interest Rate Contracts | Undesignated contracts
Derivative [Line Items]
Notional Amount	$ 750	$ 800
Progress Energy | Commodity contracts | Natural gas (millions of Dth)
Derivative [Line Items]
Notional amount, volume in millions of decatherms | Mcf	158	160
Duke Energy Progress | Interest Rate Contracts
Derivative [Line Items]
Notional Amount	$ 750	$ 250
Duke Energy Progress | Interest Rate Contracts | Undesignated contracts
Derivative [Line Items]
Notional Amount	$ 750	$ 250
Duke Energy Progress | Commodity contracts | Natural gas (millions of Dth)
Derivative [Line Items]
Notional amount, volume in millions of decatherms | Mcf	158	160
Duke Energy Florida | Interest Rate Contracts
Derivative [Line Items]
Notional Amount		$ 550
Duke Energy Florida | Interest Rate Contracts | Undesignated contracts
Derivative [Line Items]
Notional Amount		550
Duke Energy Ohio | Interest Rate Contracts
Derivative [Line Items]
Notional Amount	$ 27	27
Duke Energy Ohio | Interest Rate Contracts | Undesignated contracts
Derivative [Line Items]
Notional Amount	$ 27	$ 27
Duke Energy Ohio | Commodity contracts | Electricity (GWh)(a)
Derivative [Line Items]
Notional amount, energy measure, in gigawatt-hours | GWh	2,559	1,887
Duke Energy Indiana | Commodity contracts | Electricity (GWh)(a)
Derivative [Line Items]
Notional amount, energy measure, in gigawatt-hours | GWh	10,802	13,971
Duke Energy Indiana | Commodity contracts | Natural gas (millions of Dth)
Derivative [Line Items]
Notional amount, volume in millions of decatherms | Mcf	2	3
Piedmont | Commodity contracts | Natural gas (millions of Dth)
Derivative [Line Items]
Notional amount, volume in millions of decatherms | Mcf	373	411