Regulatory Matters (Narrative) (Details) - USD ($) $ in Millions		12 Months Ended
	Apr. 02, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Public Utilities, General Disclosures [Line Items]
Operation, maintenance and other		$ 6,066	$ 6,463	$ 5,944
Hurricane Florence, Hurricane Michael and Winter Storm Diego
Public Utilities, General Disclosures [Line Items]
Operation, maintenance and other	$ 553
Estimated capital cost	96
Duke Energy Ohio
Public Utilities, General Disclosures [Line Items]
Limit of total capital		30.00%
Operation, maintenance and other		$ 520	480	530
Duke Energy Kentucky
Public Utilities, General Disclosures [Line Items]
Required minimum equity capital structure		35.00%
Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Operation, maintenance and other		$ 1,868	2,130	2,021
Duke Energy Carolinas | Hurricane Florence, Hurricane Michael and Winter Storm Diego
Public Utilities, General Disclosures [Line Items]
Operation, maintenance and other	171
Estimated capital cost	20
Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Operation, maintenance and other		$ 1,446	$ 1,578	$ 1,439
Duke Energy Progress | Hurricane Florence, Hurricane Michael and Winter Storm Diego
Public Utilities, General Disclosures [Line Items]
Operation, maintenance and other	382
Estimated capital cost	$ 76