Severance (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) employee	Dec. 31, 2019 USD ($) employee	Dec. 31, 2018 employee
Restructuring Cost and Reserve [Line Items]
Regulatory assets	$ 14,062	$ 15,018
Number of eligible employees | employee	30	140	1,900
Duke Energy Progress
Restructuring Cost and Reserve [Line Items]
Regulatory assets	$ 4,468	$ 4,678
Duke Energy Progress | Employee Severance
Restructuring Cost and Reserve [Line Items]
Regulatory assets	33
Duke Energy Carolinas
Restructuring Cost and Reserve [Line Items]
Regulatory assets	3,469	$ 3,910
Duke Energy Carolinas | Employee Severance
Restructuring Cost and Reserve [Line Items]
Regulatory assets	$ 65