Regulatory Matters (Schedule of Net Carrying Value Of Facilities and Megawatt Capacity) (Details) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021 USD ($) MW	Dec. 31, 2034 asset	Dec. 31, 2020 USD ($)
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	$ 107,629		$ 106,782
Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	33,337		33,187
Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	23,042		22,987
Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	16,813		16,563
Duke Energy Indiana
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	$ 11,727		$ 11,721
Generation facilities to be retired
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	9,121
Public utilities, property, plant and equipment, net	$ 6,253
Generation facilities to be retired | Duke Energy Carolinas | Allen Steam Station Units 1-2
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	334
Public utilities, property, plant and equipment, net	$ 21
Generation facilities to be retired | Duke Energy Carolinas | Allen Steam Station Units 4-5
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	526
Public utilities, property, plant and equipment, net	$ 388
Generation facilities to be retired | Duke Energy Carolinas | Cliffside Unit 5
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	546
Public utilities, property, plant and equipment, net	$ 343
Generation facilities to be retired | Duke Energy Carolinas | Allen Steam Station 3
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	270
Public utilities, property, plant and equipment, net	$ 26
Generation facilities to be retired | Duke Energy Progress | Mayo Unit 1
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	746
Public utilities, property, plant and equipment, net	$ 660
Generation facilities to be retired | Duke Energy Progress | Roxboro Units 3-4
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	1,409
Public utilities, property, plant and equipment, net	$ 478
Generation facilities to be retired | Duke Energy Florida | Crystal River Units 4-5
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	1,430
Public utilities, property, plant and equipment, net	$ 1,683
Generation facilities to be retired | Duke Energy Florida | Crystal River Units 4 and 5 | Forecast
Public Utilities, General Disclosures [Line Items]
Facilities retiring ahead of schedule | asset		2
Facilities retiring ahead of schedule, years ahead		8 years
Generation facilities to be retired | Duke Energy Indiana | Gallagher Units 2 and 4
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	280
Public utilities, property, plant and equipment, net	$ 91
Generation facilities to be retired | Duke Energy Indiana | Gibson Units 1-5
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	2,845
Public utilities, property, plant and equipment, net	$ 1,834
Generation facilities to be retired | Duke Energy Indiana | Cayuga Units 1-2
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	1,005
Public utilities, property, plant and equipment, net	$ 755