Revenue (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 5,998	$ 5,928
Revenue from sources other than contracts with customers	165	207
Total operating revenues	6,163	6,135
Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	5,221	5,161
Total operating revenues	5,321	5,315
Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,370	2,350
Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,427	1,375
Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	711	664
Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	541	633
Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	172	139
Gas Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	731	717
Total operating revenues	732	702
Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	414	413
Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	206	201
Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	48	48
Gas Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	63	55
Commercial Renewables [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	42	33
Total operating revenues	106	101
Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4	17
Total operating revenues	4	17
Duke Energy Carolinas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,719	1,694
Revenue from sources other than contracts with customers	25	69
Total operating revenues	1,744	1,763
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,719	1,694
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	760	781
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	496	472
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	266	255
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	119	119
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	78	67
Progress Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,493	2,526
Revenue from sources other than contracts with customers	79	50
Total operating revenues	2,572	2,576
Progress Energy [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,493	2,526
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,114	1,112
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	632	631
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	222	208
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	353	446
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	172	129
Duke Energy Progress [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,443	1,442
Revenue from sources other than contracts with customers	41	18
Total operating revenues	1,484	1,460
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,443	1,442
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	536	516
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	306	299
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	161	145
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	315	397
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	125	85
Duke Energy Florida [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,050	1,083
Revenue from sources other than contracts with customers	36	32
Total operating revenues	1,086	1,115
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,050	1,083
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	578	595
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	326	333
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	61	62
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	38	50
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	47	43
Duke Energy Ohio [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	531	507
Revenue from sources other than contracts with customers		17
Total operating revenues	531	524
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	355	320
Total operating revenues	355	336
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	189	180
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	103	96
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	33	30
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	14
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	16	14
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	176	173
Total operating revenues	176	174
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	112	111
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	49	49
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	7	7
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	8	6
Duke Energy Ohio [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers		14
Duke Energy Indiana [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	764	714
Revenue from sources other than contracts with customers	4	17
Total operating revenues	768	731
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	764	714
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	306	278
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	197	178
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	190	173
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	54	68
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	17	17
Piedmont Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	570	557
Revenue from sources other than contracts with customers	9	(4)
Total operating revenues	579	553
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	570	557
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	302	302
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	157	152
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	42	41
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
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 56	$ 49