Organization and Basis of Presentation (Confirmed Obligations) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Duke Energy (Parent)
Contractual Obligations [Roll Forward]
Confirmed obligations at beginning of period	$ 52	$ 19	$ 87	$ 19
Invoices confirmed during the period	55	64	114	95
Confirmed invoices paid during the period	(67)	(37)	(161)	(68)
Confirmed obligations at end of period	40	46	40	46
Duke Energy Carolinas
Contractual Obligations [Roll Forward]
Confirmed obligations at beginning of period	7	1	6
Invoices confirmed during the period	10	12	20	14
Confirmed invoices paid during the period	(12)	(4)	(21)	(5)
Confirmed obligations at end of period	5	9	5	9
Progress Energy
Contractual Obligations [Roll Forward]
Confirmed obligations at beginning of period	15	9	19	9
Invoices confirmed during the period	20	20	42	31
Confirmed invoices paid during the period	(21)	(18)	(47)	(29)
Confirmed obligations at end of period	14	11	14	11
Duke Energy Progress
Contractual Obligations [Roll Forward]
Confirmed obligations at beginning of period	6	1	8
Invoices confirmed during the period	12	8	23	10
Confirmed invoices paid during the period	(6)	(6)	(19)	(7)
Confirmed obligations at end of period	12	3	12	3
Duke Energy Florida
Contractual Obligations [Roll Forward]
Confirmed obligations at beginning of period	9	8	11	9
Invoices confirmed during the period	8	12	19	21
Confirmed invoices paid during the period	(15)	(12)	(28)	(22)
Confirmed obligations at end of period	2	8	2	8
Duke Energy Ohio
Contractual Obligations [Roll Forward]
Confirmed obligations at beginning of period		4	5	6
Invoices confirmed during the period	2	9	3	15
Confirmed invoices paid during the period		(4)	(6)	(12)
Confirmed obligations at end of period	2	9	2	9
Duke Energy Indiana
Contractual Obligations [Roll Forward]
Confirmed obligations at beginning of period		1
Invoices confirmed during the period		(1)		1
Confirmed invoices paid during the period				(1)
Piedmont
Contractual Obligations [Roll Forward]
Confirmed obligations at beginning of period	29	5	57	4
Invoices confirmed during the period	24	23	49	34
Confirmed invoices paid during the period	(34)	(11)	(87)	(21)
Confirmed obligations at end of period	$ 19	$ 17	$ 19	$ 17