Quarterly Financial Data (Unaudited) (Schedule of Quarterly Financial Information) (Details) - USD ($) $ / shares in Units, $ in Millions	2 Months Ended	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Oct. 31, 2016
Quarterly Financial Information Disclosure [Line Items]
Operating revenues		$ 6,115	$ 6,628	$ 5,643	$ 6,135	$ 5,799	$ 6,482	$ 5,555	$ 5,729	$ 24,521	$ 23,565	$ 22,743
Operating income (loss)		871	1,579	979	1,256	1,209	1,661	1,353	1,402	4,685	5,625	5,202
Income (loss) from continuing operations		434	1,062	507	622	705	957	691	717	2,625	3,070	2,578
Income (Loss) From Discontinued Operations, net of tax		20	4	(5)		(2)	(2)	(2)		19	(6)	(408)
Net income (loss)		454	1,066	502	622	703	955	689	717	2,644	3,064	2,170
Net Income (Loss) Attributable to Parent		$ 464	$ 1,082	$ 500	$ 620	$ 703	$ 954	$ 686	$ 716	$ 2,666	$ 3,059	$ 2,152
Income (loss) from continuing operations attributable to Duke Energy Corporation common shareholders [Abstract]
Basic (in usd per share)		$ 0.62	$ 1.51	$ 0.72	$ 0.88	$ 1.00	$ 1.36	$ 0.98	$ 1.02	$ 3.73	$ 4.37	$ 3.71
Diluted (in usd per share)		0.62	1.51	0.72	0.88	1.00	1.36	0.98	1.02	3.73	4.37	3.71
Income (loss) from discontinued operations attributable to Duke Energy Corporation common shareholders [Abstract]
Basic (in usd per share)		0.03		(0.01)						0.03	(0.01)	(0.60)
Diluted (in usd per share)		0.03		(0.01)						0.03	(0.01)	(0.60)
Net income attributable to Duke Energy Corporation common stockholders
Basic (in usd per share)		0.65	1.51	0.71	0.88	1.00	1.36	0.98	1.02	3.76	4.36	3.11
Diluted (in usd per share)		$ 0.65	$ 1.51	$ 0.71	$ 0.88	$ 1.00	$ 1.36	$ 0.98	$ 1.02	$ 3.76	$ 4.36	$ 3.11
Duke Energy Carolinas [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues		$ 1,775	$ 2,090	$ 1,672	$ 1,763	$ 1,721	$ 2,136	$ 1,729	$ 1,716	$ 7,300	$ 7,302	$ 7,322
Operating income (loss)		241	713	224	482	384	763	471	471	1,660	2,089	2,010
Net Income (Loss) Attributable to Parent		135	496	117	323	205	466	273	270	1,071	1,214	1,166
Progress Energy [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues		2,609	3,045	2,498	2,576	2,348	2,864	2,392	2,179	10,728	9,783	9,853
Operating income (loss)		334	663	484	447	459	641	576	471	1,928	2,147	2,069
Income (loss) from continuing operations										1,033	1,268	1,039
Income (Loss) From Discontinued Operations, net of tax												2
Net income (loss)		123	406	267	237	447	343	277	201	1,033	1,268	1,041
Net Income (Loss) Attributable to Parent		123	404	265	235	444	341	274	199	1,027	1,258	1,031
Duke Energy Progress [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues		1,366	1,582	1,291	1,460	1,251	1,460	1,199	1,219	5,699	5,129	5,277
Operating income (loss)		227	330	233	269	243	398	270	274	1,059	1,185	1,025
Net Income (Loss) Attributable to Parent		135	216	139	177	168	246	154	147	667	715	599
Duke Energy Florida [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues		1,241	1,462	1,203	1,115	1,095	1,401	1,191	959	5,021	4,646	4,568
Operating income (loss)		107	331	245	173	212	236	301	192	856	941	1,022
Net Income (Loss) Attributable to Parent		40	243	168	103	344	120	158	90	554	712	551
Duke Energy Ohio [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues		505	469	459	524	497	471	437	518	1,957	1,923	1,944
Operating income (loss)		93	139	77	(21)	73	101	64	82	288	320	345
Income (loss) from continuing operations										176	193	192
Income (Loss) From Discontinued Operations, net of tax							(1)				(1)	36
Net Income (Loss) Attributable to Parent		55	100	46	(25)	65	55	30	42	176	192	228
Duke Energy Indiana [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues		771	819	738	731	745	802	742	758	3,059	3,047	2,958
Operating income (loss)		133	173	169	168	166	228	208	184	643	786	761
Net Income (Loss) Attributable to Parent		76	119	98	100	36	121	106	91	393	354	$ 381
Piedmont Natural Gas [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	$ 322	435	172	215	553	444	183	201	500	1,375	1,328		$ 1,149
Operating income (loss)	98	79	(19)	5	161	126	(4)	5	170	226	297		225
Net Income (Loss) Attributable to Parent	$ 54	$ 48	$ (21)	$ (8)	$ 110	$ 63	$ (11)	$ (8)	$ 95	$ 129	$ 139		$ 193