Revenue (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 6,792	$ 6,451	$ 18,485	$ 17,845
Revenue from sources other than contracts with customers	148	177	491	561
Total operating revenues	6,940	6,628	18,976	18,406
Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6,492	6,141	17,074	16,413
Total operating revenues	6,569	6,253	17,357	16,783
Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,923	2,729	7,597	7,264
Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,885	1,763	4,896	4,619
Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	869	835	2,339	2,235
Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	617	589	1,685	1,737
Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	198	225	557	558
Gas Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	223	233	1,236	1,244
Total operating revenues	225	232	1,239	1,229
Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	113	116	673	682
Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	68	66	359	354
Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	26	28	103	107
Gas Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	16	23	101	101
Commercial Renewables [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	69	61	157	141
Total operating revenues	138	127	362	347
Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	8	16	18	47
Total operating revenues	8	16	18	47
Duke Energy Carolinas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,140	2,051	5,535	5,391
Revenue from sources other than contracts with customers	22	39	84	134
Total operating revenues	2,162	2,090	5,619	5,525
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,140	2,051	5,535	5,391
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	892	823	2,331	2,263
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	687	635	1,714	1,608
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	372	352	927	893
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	113	132	341	366
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	76	109	222	261
Progress Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,167	2,977	8,334	7,922
Revenue from sources other than contracts with customers	75	68	224	197
Total operating revenues	3,242	3,045	8,558	8,119
Progress Energy [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,167	2,977	8,334	7,922
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,522	1,425	3,879	3,636
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	843	800	2,225	2,109
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	255	246	708	678
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	429	372	1,133	1,140
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	118	134	389	359
Duke Energy Progress [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,651	1,547	4,446	4,234
Revenue from sources other than contracts with customers	37	35	113	99
Total operating revenues	1,688	1,582	4,559	4,333
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,651	1,547	4,446	4,234
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	625	572	1,657	1,540
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	399	373	1,044	972
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	189	177	514	481
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	368	335	992	1,019
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	70	90	239	222
Duke Energy Florida [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,516	1,430	3,888	3,688
Revenue from sources other than contracts with customers	32	32	99	92
Total operating revenues	1,548	1,462	3,987	3,780
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,516	1,430	3,888	3,688
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	897	853	2,222	2,096
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	444	427	1,181	1,137
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	66	69	194	197
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	61	37	141	121
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	48	44	150	137
Duke Energy Ohio [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	494	466	1,454	1,435
Revenue from sources other than contracts with customers	(5)	3	(1)	17
Total operating revenues	489	469	1,453	1,452
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	413	371	1,102	1,040
Total operating revenues	408	373	1,099	1,055
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	215	203	563	564
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	127	112	335	318
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	40	33	109	96
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	13	3	36	5
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	18	20	59	57
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	81	83	352	359
Total operating revenues	81	84	354	361
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	53	59	229	236
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	21	20	96	97
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4	3	14	13
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3	1	13	13
Duke Energy Ohio [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers		12		36
Duke Energy Indiana [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	808	809	2,281	2,245
Revenue from sources other than contracts with customers	(1)	10	8	43
Total operating revenues	807	819	2,289	2,288
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	808	809	2,281	2,245
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	294	279	825	802
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	225	218	619	584
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	204	202	595	567
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	63	81	176	226
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	22	29	66	66
Piedmont Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	157	162	924	924
Revenue from sources other than contracts with customers	11	10	32	16
Total operating revenues	168	172	956	940
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	157	162	924	924
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	59	57	443	446
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	47	46	263	257
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	25	24	91	93
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Power Generation [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	13	13	39	40
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 13	$ 22	$ 88	$ 88