Quarterly Financial Data (Unaudited) (Schedule of Quarterly Financial Information) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	$ 6,103	$ 6,940	$ 5,873	$ 6,163	$ 6,115	$ 6,628	$ 5,643	$ 6,135	$ 25,079	$ 24,521	$ 23,565
Operating income (loss)	1,109	1,929	1,298	1,373	871	1,579	979	1,256	5,709	4,685	5,625
Income (loss) from continuing operations	614	1,323	748	893	434	1,062	507	622	3,578	2,625	3,070
(Loss) Income from discontinued operations, net of tax	(7)				20	4	(5)	0	(7)	19	(6)
Net income (loss)	607	1,323	748	893	454	1,066	502	622	3,571	2,644	3,064
Net income (loss) attributable to parent					$ (464)	$ (1,082)	$ (500)	$ (620)	(3,748)	(2,666)	(3,059)
Net Income (Loss) Available to Common Stockholders, Basic	$ 660	$ 1,327	$ 820	$ 900					$ 3,707	$ 2,666	$ 3,059
Income (loss) from continuing operations attributable to Duke Energy Corporation common shareholders [Abstract]
Basic and diluted (in usd per share)	$ 0.89	$ 1.82	$ 1.12	$ 1.24	$ 0.62	$ 1.51	$ 0.72	$ 0.88	$ 5.07	$ 3.73	$ 4.37
Income (loss) from discontinued operations attributable to Duke Energy Corporation common shareholders [Abstract]
Basic and diluted (in usd per share)	(0.01)		0	0	0.03	0	(0.01)	0	(0.01)	0.03	(0.01)
Net income available to Duke Energy Corporation common stockholders
Basic and diluted (in usd per share)	$ 0.88	$ 1.82	$ 1.12	$ 1.24	$ 0.65	$ 1.51	$ 0.71	$ 0.88	$ 5.06	$ 3.76	$ 4.36
Duke Energy Carolinas
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	$ 1,776	$ 2,162	$ 1,713	$ 1,744	$ 1,775	$ 2,090	$ 1,672	$ 1,763	$ 7,395	$ 7,300	$ 7,302
Operating income (loss)	347	793	451	435	241	713	224	482	2,026	1,660	2,089
Net income (loss) attributable to parent	(219)	(590)	(301)	(293)	(135)	(496)	(117)	(323)	(1,403)	(1,071)	(1,214)
Progress Energy
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	2,644	3,242	2,744	2,572	2,609	3,045	2,498	2,576	11,202	10,728	9,783
Operating income (loss)	447	786	580	488	334	663	484	447	2,301	1,928	2,147
Net income (loss)	229	521	329	248	123	406	267	237	1,327	1,033	1,268
Net income (loss) attributable to parent	(229)	(521)	(328)	(249)	(123)	(404)	(265)	(235)	(1,327)	(1,027)	(1,258)
Duke Energy Progress
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	1,398	1,688	1,387	1,484	1,366	1,582	1,291	1,460	5,957	5,699	5,129
Operating income (loss)	236	373	259	300	227	330	233	269	1,168	1,059	1,185
Net income (loss) attributable to parent	(155)	(278)	(169)	(203)	(135)	(216)	(139)	(177)	(805)	(667)	(715)
Duke Energy Florida
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	1,244	1,548	1,353	1,086	1,241	1,462	1,203	1,115	5,231	5,021	4,646
Operating income (loss)	205	413	321	188	107	331	245	173	1,127	856	941
Net income (loss) attributable to parent	(106)	(289)	(201)	(96)	(40)	(243)	(168)	(103)	(692)	(554)	(712)
Duke Energy Ohio
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	487	489	433	531	505	469	459	524	1,940	1,957	1,923
Operating income (loss)	78	108	74	104	93	139	77	(21)	364	288	320
Income (loss) from continuing operations									239	176	193
(Loss) Income from discontinued operations, net of tax									(1)		(1)
Net income (loss) attributable to parent	(48)	(74)	(47)	(69)	(55)	(100)	(46)	25	(238)	(176)	(192)
Duke Energy Indiana
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	715	807	714	768	771	819	738	731	3,004	3,059	3,047
Operating income (loss)	133	235	148	169	133	173	169	168	685	643	786
Net income (loss) attributable to parent	(73)	(156)	(97)	(110)	(76)	(119)	(98)	(100)	(436)	(393)	(354)
Piedmont
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	425	168	209	579	435	172	215	553	1,381	1,375	1,328
Operating income (loss)	139	(13)	6	172	79	(19)	5	161	304	226	297
Net income (loss) attributable to parent	$ (105)	$ 18	$ 7	$ (122)	$ (48)	$ 21	$ 8	$ (110)	$ (202)	$ (129)	$ (139)