Quarterly Financial Data (Schedule of Quarterly Financial Information) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	$ 6,112	$ 6,709	$ 5,879	$ 5,898	$ 5,695	$ 6,722	$ 3,577	$ 3,630	$ 24,598	$ 19,624	$ 14,529
Operating income (loss)	1,203	1,743	821	1,215	767	1,078	786	495	4,982	3,126	2,777
Income (loss) from continuing operations	686	994	345	634	406	594	449	297	2,659	1,746	1,713
Net income (loss)	692	1,008	342	634	437	598	448	299	2,676	1,782	1,714
Net income (loss) attributable to Duke Energy Corporation	688	1,004	339	634	435	594	444	295	2,665	1,768	1,706
Income (loss) from continuing operations attributable to Duke Energy Corporation common shareholders [Abstract]
Basic	$ 0.96	$ 1.40	$ 0.48	$ 0.89	$ 0.57	$ 0.84	$ 0.99	$ 0.66	$ 3.74	$ 3.01	$ 3.83
Diluted	$ 0.96	$ 1.40	$ 0.48	$ 0.89	$ 0.57	$ 0.84	$ 0.99	$ 0.66	$ 3.74	$ 3.01	$ 3.83
Net income attributable to Duke Energy Corporation common shareholders [Abstract]
Basic	$ 0.97	$ 1.42	$ 0.48	$ 0.89	$ 0.62	$ 0.85	$ 0.99	$ 0.66	$ 3.77	$ 3.07	$ 3.83
Diluted	$ 0.97	$ 1.42	$ 0.48	$ 0.89	$ 0.62	$ 0.85	$ 0.99	$ 0.66	$ 3.76	$ 3.07	$ 3.83
Duke Energy Carolinas [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	1,715	1,919	1,591	1,729	1,609	1,939	1,616	1,501	6,954	6,665	6,493
Operating income (loss)	420	604	351	434	216	440	386	475	1,809	1,517	1,480
Net income (loss)	209	342	181	244	130	258	211	266	976	865	834
Progress Energy [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	2,300	2,766	2,281	2,186	2,227	2,788	2,288	2,102	9,533	9,405	8,948
Operating income (loss)	403	671	114	430	118	379	277	363	1,618	1,137	1,583
Income (loss) from continuing operations	190	328	(13)	154	(8)	154	68	141	659	355	587
Net income (loss)	196	342	(17)	154	34	157	64	152	675	407	582
Net income (loss) attributable to Duke Energy Corporation	195	341	(17)	153	32	155	63	150	672	400	575
Duke Energy Progress [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	1,211	1,430	1,135	1,216	1,128	1,398	1,090	1,090	4,992	4,706	4,547
Operating income (loss)	251	303	166	212	148	172	83	107	932	510	876
Net income (loss)	138	175	77	110	93	96	31	52	500	272	516
Duke Energy Florida [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	1,085	1,332	1,142	968	1,095	1,388	1,196	1,010	4,527	4,689	4,392
Operating income (loss)	151	369	(53)	221	(29)	207	196	255	688	629	703
Net income (loss)	75	197	(57)	110	(45)	100	83	128	325	266	314
Duke Energy Ohio [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	868	819	811	747	766	757	717	912	3,245	3,152	3,181
Operating income (loss)	44	116	108	(17)	74	42	95	138	251	349	375
Net income (loss)	6	59	58	(21)	42	14	45	74	102	175	194
Duke Energy Indiana [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	747	755	700	724	626	718	685	688	2,926	2,717	2,622
Operating income (loss)	181	203	168	181	93	(30)	134	(272)	733	(75)	282
Net income (loss)	$ 82	$ 104	$ 82	$ 90	$ 59	$ (19)	$ 77	$ (167)	$ 358	$ (50)	$ 168