Regulatory Matters (Schedule of Net Carrying Value Of Facilities and Megawatt Capacity) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020 USD ($) MW	Dec. 31, 2019 USD ($)
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	$ 104,325	$ 102,127
Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	32,970	32,397
Duke Energy Indiana
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	$ 11,264	$ 11,072
Generation facilities to be retired
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	5,002
Public utilities, property, plant and equipment, net	$ 2,904
Generation facilities to be retired | Allen Steam Station Units 1-3 | Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	585
Public utilities, property, plant and equipment, net	$ 145
Generation facilities to be retired | Gallagher Units 2 and 4 | Duke Energy Indiana
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	280
Public utilities, property, plant and equipment, net	$ 116
Generation facilities to be retired | Gibson Units 1-5 | Duke Energy Indiana
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	3,132
Public utilities, property, plant and equipment, net	$ 1,690
Generation facilities to be retired | Cayuga Units 1-2 | Duke Energy Indiana
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	1,005
Public utilities, property, plant and equipment, net	$ 953