Derivatives and Hedging (Schedule of Offsetting Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Offsetting Liabilities [Line Items]
Gross amounts recognized	$ 472	$ 324
Net amounts presented on Balance Sheets	472	324
Current Liabilities
Offsetting Liabilities [Line Items]
Gross amounts recognized	184	64
Gross amounts offset	(11)	(3)
Net amounts presented on Balance Sheets	173	61
Noncurrent Liabilities
Offsetting Liabilities [Line Items]
Gross amounts recognized	288	260
Gross amounts offset	(12)	(5)
Net amounts presented on Balance Sheets	276	255
Duke Energy Carolinas
Offsetting Liabilities [Line Items]
Gross amounts recognized	35	20
Net amounts presented on Balance Sheets	35	20
Duke Energy Carolinas | Current Liabilities
Offsetting Liabilities [Line Items]
Gross amounts recognized	26	17
Gross amounts offset	(6)	(2)
Net amounts presented on Balance Sheets	20	15
Duke Energy Carolinas | Noncurrent Liabilities
Offsetting Liabilities [Line Items]
Gross amounts recognized	9	3
Gross amounts offset	(8)	(1)
Net amounts presented on Balance Sheets	1	2
Progress Energy
Offsetting Liabilities [Line Items]
Gross amounts recognized	24	29
Net amounts presented on Balance Sheets	24	29
Progress Energy | Current Liabilities
Offsetting Liabilities [Line Items]
Gross amounts recognized	19	2
Gross amounts offset	(5)	(2)
Net amounts presented on Balance Sheets	14
Progress Energy | Noncurrent Liabilities
Offsetting Liabilities [Line Items]
Gross amounts recognized	5	27
Gross amounts offset	(5)	(4)
Net amounts presented on Balance Sheets		23
Duke Energy Progress
Offsetting Liabilities [Line Items]
Gross amounts recognized	10	14
Net amounts presented on Balance Sheets	10	14
Duke Energy Progress | Current Liabilities
Offsetting Liabilities [Line Items]
Gross amounts recognized	5	2
Gross amounts offset	(5)	(2)
Duke Energy Progress | Noncurrent Liabilities
Offsetting Liabilities [Line Items]
Gross amounts recognized	5	12
Gross amounts offset	(5)	(4)
Net amounts presented on Balance Sheets		8
Duke Energy Florida
Offsetting Liabilities [Line Items]
Gross amounts recognized	14
Net amounts presented on Balance Sheets	14
Duke Energy Florida | Current Liabilities
Offsetting Liabilities [Line Items]
Gross amounts recognized	14
Net amounts presented on Balance Sheets	14
Duke Energy Ohio
Offsetting Liabilities [Line Items]
Gross amounts recognized	5	6
Duke Energy Ohio | Current Liabilities
Offsetting Liabilities [Line Items]
Gross amounts recognized	1	1
Net amounts presented on Balance Sheets	1	1
Duke Energy Ohio | Noncurrent Liabilities
Offsetting Liabilities [Line Items]
Gross amounts recognized	4	5
Net amounts presented on Balance Sheets	4	5
Duke Energy Indiana
Offsetting Liabilities [Line Items]
Gross amounts recognized	27	1
Net amounts presented on Balance Sheets	27	1
Duke Energy Indiana | Current Liabilities
Offsetting Liabilities [Line Items]
Gross amounts recognized	13	1
Net amounts presented on Balance Sheets	13	1
Duke Energy Indiana | Noncurrent Liabilities
Offsetting Liabilities [Line Items]
Gross amounts recognized	14
Net amounts presented on Balance Sheets	14
Piedmont
Offsetting Liabilities [Line Items]
Gross amounts recognized	139	122
Net amounts presented on Balance Sheets	139	122
Piedmont | Current Liabilities
Offsetting Liabilities [Line Items]
Gross amounts recognized	21	15
Net amounts presented on Balance Sheets	21	15
Piedmont | Noncurrent Liabilities
Offsetting Liabilities [Line Items]
Gross amounts recognized	118	107
Net amounts presented on Balance Sheets	$ 118	$ 107