Fair Value Measurements (Other Fair Value Disclosure) (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Book Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 66,318	$ 63,835
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	61,451	69,683
Piedmont Natural Gas and Progress Energy
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unamortized debt discount (premium), net	1,210	1,250
Duke Energy Carolinas | Book Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	14,162	13,275
Duke Energy Carolinas | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	13,501	15,101
Progress Energy | Book Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	20,751	20,823
Progress Energy | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	19,830	23,751
Duke Energy Progress | Book Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	10,662	10,249
Duke Energy Progress | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	9,829	11,252
Duke Energy Florida | Book Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	8,447	8,482
Duke Energy Florida | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	8,150	9,772
Duke Energy Ohio | Book Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	3,243	3,193
Duke Energy Ohio | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	3,071	3,570
Duke Energy Indiana | Book Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	4,337	4,323
Duke Energy Indiana | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	4,168	5,067
Piedmont | Book Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	3,363	2,968
Piedmont | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 3,086	$ 3,278