Related Party Transactions (Other Revenue and Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
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	$ 894	$ 753	$ 841
Duke Energy Carolinas | Indemnification coverages | Affiliated entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	24	20	20
Duke Energy Carolinas | Joint Dispatch Agreement (JDA) revenue | Duke Energy Progress
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	207	114	186
Related party transaction, other revenues from transactions with related party	41	25	60
Duke Energy Carolinas | Intercompany natural gas transactions | Affiliated entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	11	15	15
Progress Energy | Corporate governance and shared service expenses | Affiliated entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	856	715	778
Progress Energy | Indemnification coverages | Affiliated entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	41	36	37
Progress Energy | Joint Dispatch Agreement (JDA) revenue | Duke Energy Carolinas
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	41	25	60
Related party transaction, other revenues from transactions with related party	207	114	186
Progress Energy | Intercompany natural gas transactions | Affiliated entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	75	75	76
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	504	420	462
Duke Energy Progress | Indemnification coverages | Affiliated entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	19	17	15
Duke Energy Progress | Joint Dispatch Agreement (JDA) revenue | Duke Energy Carolinas
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	41	25	60
Related party transaction, other revenues from transactions with related party	207	114	186
Duke Energy Progress | Intercompany natural gas transactions | Affiliated entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	75	75	76
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	352	295	316
Duke Energy Florida | Indemnification coverages | Affiliated entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	22	19	22
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	329	326	354
Duke Energy Ohio | Indemnification coverages | Affiliated entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	4	4	4
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	409	401	412
Duke Energy Indiana | Indemnification coverages | Affiliated entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	8	8	7
Piedmont | Corporate governance and shared service expenses | Affiliated entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	139	140	138
Piedmont | Indemnification coverages | Affiliated entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	3	3	3
Piedmont | Intercompany natural gas transactions | Affiliated entity
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	86	90	91
Piedmont | Natural gas storage and transportation costs | Affiliated entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$ 22	$ 23	$ 23