Regulatory Matters (Schedule of Net Carrying Value Of Facilities and Megawatt Capacity) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($) MW	Dec. 31, 2019 USD ($)
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	$ 103,108	$ 102,127
Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	32,650	32,397
Duke Energy Indiana
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	$ 11,132	$ 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	$ 2,939
Allen Steam Station Units 1-3 | Generation facilities to be retired | Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	585
Public utilities, property, plant and equipment, net	$ 149
Gallagher Units 2 and 4 | Generation facilities to be retired | Duke Energy Indiana
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	280
Public utilities, property, plant and equipment, net	$ 118
Gibson Units 1-5 | Generation facilities to be retired | Duke Energy Indiana
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	3,132
Public utilities, property, plant and equipment, net	$ 1,708
Cayuga Units 1-2 | Generation facilities to be retired | Duke Energy Indiana
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	1,005
Public utilities, property, plant and equipment, net	$ 964