Organization and Basis of Presentation (Confirmed Obligations) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Duke Energy (Parent)
Contractual Obligations [Roll Forward]
Confirmed obligations at beginning of period	$ 50	$ 87
Invoices confirmed during the period	57	59
Confirmed invoices paid during the period	(31)	(94)
Confirmed obligations at end of period	76	52
Duke Energy Carolinas
Contractual Obligations [Roll Forward]
Confirmed obligations at beginning of period	0	6
Invoices confirmed during the period	0	10
Confirmed invoices paid during the period	0	(9)
Confirmed obligations at end of period	0	7
Progress Energy
Contractual Obligations [Roll Forward]
Confirmed obligations at beginning of period	3	19
Invoices confirmed during the period	1	22
Confirmed invoices paid during the period	(2)	(26)
Confirmed obligations at end of period	2	15
Duke Energy Progress
Contractual Obligations [Roll Forward]
Confirmed obligations at beginning of period	0	8
Invoices confirmed during the period	0	11
Confirmed invoices paid during the period	0	(13)
Confirmed obligations at end of period	0	6
Duke Energy Florida
Contractual Obligations [Roll Forward]
Confirmed obligations at beginning of period	3	11
Invoices confirmed during the period	1	11
Confirmed invoices paid during the period	(2)	(13)
Confirmed obligations at end of period	2	9
Duke Energy Ohio
Contractual Obligations [Roll Forward]
Confirmed obligations at beginning of period	0	5
Invoices confirmed during the period	0	1
Confirmed invoices paid during the period	0	(6)
Confirmed obligations at end of period	0	0
Duke Energy Indiana
Contractual Obligations [Roll Forward]
Confirmed obligations at beginning of period	0	0
Invoices confirmed during the period	0	0
Confirmed invoices paid during the period	0	0
Confirmed obligations at end of period	0	0
Piedmont
Contractual Obligations [Roll Forward]
Confirmed obligations at beginning of period	47	57
Invoices confirmed during the period	56	25
Confirmed invoices paid during the period	(29)	(53)
Confirmed obligations at end of period	$ 74	$ 29