Derivatives and Hedging (Schedule of Offsetting Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Offsetting Assets [Line Items]
Gross amounts recognized	$ 320	$ 61
Net amounts presented on Balance Sheets	320	61
Current Assets
Offsetting Assets [Line Items]
Gross amounts recognized	204	48
Gross amounts offset	(25)	(3)
Net amounts presented on Balance Sheets	179	45
Noncurrent assets
Offsetting Assets [Line Items]
Gross amounts recognized	116	13
Gross amounts offset	(23)	(5)
Net amounts presented on Balance Sheets	93	8
Duke Energy Carolinas
Offsetting Assets [Line Items]
Gross amounts recognized	162	20
Net amounts presented on Balance Sheets	162	20
Duke Energy Carolinas | Current Assets
Offsetting Assets [Line Items]
Gross amounts recognized	99	14
Gross amounts offset	(16)	(2)
Net amounts presented on Balance Sheets	83	12
Duke Energy Carolinas | Noncurrent assets
Offsetting Assets [Line Items]
Gross amounts recognized	63	6
Gross amounts offset	(15)	(1)
Net amounts presented on Balance Sheets	48	5
Progress Energy
Offsetting Assets [Line Items]
Gross amounts recognized	124	33
Net amounts presented on Balance Sheets	124	33
Progress Energy | Current Assets
Offsetting Assets [Line Items]
Gross amounts recognized	74	27
Gross amounts offset	(9)	(2)
Net amounts presented on Balance Sheets	65	25
Progress Energy | Noncurrent assets
Offsetting Assets [Line Items]
Gross amounts recognized	50	6
Gross amounts offset	(8)	(4)
Net amounts presented on Balance Sheets	42	2
Duke Energy Progress
Offsetting Assets [Line Items]
Gross amounts recognized	124	33
Net amounts presented on Balance Sheets	124	33
Duke Energy Progress | Current Assets
Offsetting Assets [Line Items]
Gross amounts recognized	74	27
Gross amounts offset	(9)	(2)
Net amounts presented on Balance Sheets	65	25
Duke Energy Progress | Noncurrent assets
Offsetting Assets [Line Items]
Gross amounts recognized	50	6
Gross amounts offset	(8)	(4)
Net amounts presented on Balance Sheets	42	2
Duke Energy Ohio
Offsetting Assets [Line Items]
Gross amounts recognized	2	1
Duke Energy Ohio | Current Assets
Offsetting Assets [Line Items]
Gross amounts recognized	2	1
Net amounts presented on Balance Sheets	2	1
Duke Energy Indiana
Offsetting Assets [Line Items]
Gross amounts recognized	23	6
Net amounts presented on Balance Sheets	23	6
Duke Energy Indiana | Current Assets
Offsetting Assets [Line Items]
Gross amounts recognized	23	6
Net amounts presented on Balance Sheets	23	6
Piedmont
Offsetting Assets [Line Items]
Gross amounts recognized	3	1
Net amounts presented on Balance Sheets	3	1
Piedmont | Current Assets
Offsetting Assets [Line Items]
Gross amounts recognized	3	1
Net amounts presented on Balance Sheets	$ 3	$ 1