Related Party Transactions (Other Revenue and Expense) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Duke Energy Carolinas | Corporate governance and shared service expenses | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$ 191	$ 243	$ 397	$ 446
Duke Energy Carolinas | Indemnification coverages | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	7	6	14	12
Duke Energy Carolinas | JDA | Duke Energy Progress
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	173	25	267	65
Related party transaction, other revenues from transactions with related party	12	13	38	26
Duke Energy Carolinas | Intercompany natural gas purchases and sales | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	5	15	9	29
Progress Energy | Corporate governance and shared service expenses | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	184	233	380	414
Progress Energy | Indemnification coverages | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	11	11	22	21
Progress Energy | JDA | Duke Energy Carolinas
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	12	13	38	26
Related party transaction, other revenues from transactions with related party	173	25	267	65
Progress Energy | Intercompany natural gas purchases and sales | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	19	18	38	37
Duke Energy Progress | Corporate governance and shared service expenses | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	108	141	227	246
Duke Energy Progress | Indemnification coverages | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	5	5	10	10
Duke Energy Progress | JDA | Duke Energy Carolinas
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	12	13	38	26
Related party transaction, other revenues from transactions with related party	173	25	267	65
Duke Energy Progress | Intercompany natural gas purchases and sales | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	19	18	38	37
Duke Energy Florida | Corporate governance and shared service expenses | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	76	92	153	168
Duke Energy Florida | Indemnification coverages | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	6	6	12	11
Duke Energy Ohio | Corporate governance and shared service expenses | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	82	79	164	158
Duke Energy Ohio | Indemnification coverages | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	1	1	2	2
Duke Energy Indiana | Corporate governance and shared service expenses | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	91	93	215	206
Duke Energy Indiana | Indemnification coverages | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	2	2	4	4
Piedmont | Corporate governance and shared service expenses | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	37	36	72	69
Piedmont | Indemnification coverages | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	2	1	3	2
Piedmont | Intercompany natural gas purchases and sales | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	24	33	47	66
Piedmont | Natural gas storage and transportation costs | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$ 5	$ 5	$ 11	$ 11