Quarterly Financial Data (Unaudited) (Schedule of Quarterly Financial Information) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	$ 5,322	$ 6,483	$ 5,589	$ 6,065	$ 5,559	$ 6,395	$ 5,708	$ 6,263	$ 23,459	$ 23,925	$ 22,756
Operating income (loss)	977	1,688	1,246	1,456	988	1,619	1,289	1,362	5,367	5,258	4,854
Income (loss) from continuing operations	491	940	604	776	98	891	726	750	2,811	2,465	2,590
Income (Loss) From Discontinued Operations, net of tax	(9)	(5)	(57)	91	2	378	(113)	(843)	20	(576)	86
Net income (loss)	482	935	547	867	100	1,269	613	(93)	2,831	1,889	2,676
Net income (loss) attributable to Parent	$ 477	$ 932	$ 543	$ 864	$ 97	$ 1,274	$ 609	$ (97)	$ 2,816	$ 1,883	$ 2,665
Income (loss) from continuing operations attributable to Duke Energy Corporation common shareholders [Abstract]
Basic	$ 0.70	$ 1.36	$ 0.87	$ 1.09	$ 0.14	$ 1.25	$ 1.02	$ 1.05	$ 4.02	$ 3.46	$ 3.64
Diluted	0.70	1.36	0.87	1.09	0.14	1.25	1.02	1.05	4.02	3.46	3.63
Income (loss) from discontinued operations attributable To Duke Energy Corporation common shareholders [Abstract]
Basic	(0.01)	(0.01)	(0.09)	0.13		0.55	(0.16)	(1.19)	0.03	(0.80)	0.13
Diluted	(0.01)	(0.01)	(0.09)	0.13		0.55	(0.16)	(1.19)	0.03	(0.80)	0.13
Net income attributable to Duke Energy Corporation common shareholders [Abstract]
Basic	0.69	1.35	0.78	1.22	0.14	1.80	0.86	(0.14)	4.05	2.66	3.77
Diluted	$ 0.69	$ 1.35	$ 0.78	$ 1.22	$ 0.14	$ 1.80	$ 0.86	$ (0.14)	$ 4.05	$ 2.66	$ 3.76
Duke Energy Carolinas [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	$ 1,560	$ 2,061	$ 1,707	$ 1,901	$ 1,658	$ 1,938	$ 1,755	$ 2,000	$ 7,229	$ 7,351	$ 6,954
Operating income (loss)	296	666	483	515	318	630	438	509	1,960	1,895	1,809
Net income (loss)	141	383	265	292	139	377	270	286	1,081	1,072
Net income (loss) attributable to Parent									1,081	1,072	976
Progress Energy [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	2,336	2,929	2,476	2,536	2,341	2,863	2,421	2,541	10,277	10,166	9,533
Operating income (loss)	351	756	504	549	388	665	488	477	2,160	2,018	1,618
Income (loss) from continuing operations	132	452	217	264	139	330	207	204	1,065	880	659
Income (Loss) From Discontinued Operations, net of tax									(3)	(6)	16
Net income (loss)	131	451	217	263	139	330	202	203	1,062	874	675
Net income (loss) attributable to Parent	128	448	215	260	136	329	202	202	1,051	869	672
Duke Energy Progress [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	1,160	1,488	1,193	1,449	1,196	1,367	1,191	1,422	5,290	5,176	4,992
Operating income (loss)	130	394	184	316	180	285	212	258	1,024	935	932
Net income (loss)	69	229	85	183	76	157	101	133	566	467	500
Net income (loss) attributable to Parent									566	467	500
Duke Energy Florida [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	1,174	1,436	1,281	1,086	1,143	1,491	1,225	1,116	4,977	4,975	4,527
Operating income (loss)	216	357	315	227	205	378	276	219	1,115	1,078	688
Net income (loss)	105	216	165	113	93	205	142	108	599	548	325
Net income (loss) attributable to Parent									599	548	325
Duke Energy Ohio [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	452	462	405	586	480	446	412	575	1,905	1,913	1,805
Operating income (loss)	73	76	43	111	76	58	60	(7)	303	187	182
Income (loss) from continuing operations									149	68	67
Income (Loss) From Discontinued Operations, net of tax		(2)	(65)	90	34	413	(135)	(875)	23	(563)	35
Net income (loss)	43	32	(52)	149	63	439	(107)	(890)	172	(495)	102
Net income (loss) attributable to Parent									172	(495)	102
Duke Energy Indiana [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	667	749	686	788	792	790	748	845	2,890	3,175	2,926
Operating income (loss)	171	117	146	210	130	182	178	215	644	705	733
Net income (loss)	$ 94	$ 46	$ 68	$ 108	$ 58	$ 101	$ 87	$ 113	316	359
Net income (loss) attributable to Parent									$ 316	$ 359	$ 358