Regulatory Matters (Schedule of Regulatory Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	$ 15,018	$ 15,622
Regulatory Assets: Current	1,796	2,005
Other Noncurrent Assets: Regulatory assets	13,222	13,617
Total regulatory liabilities	16,048	15,432
Less: current portion	784	598
Total noncurrent regulatory liabilities	15,264	14,834
Net regulatory liability related to income taxes
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	7,872	8,058
Costs of removal
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	5,756	5,421
AROs – nuclear and other
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	1,100	538
Accrued pension and OPEB
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	176	301
Amounts to be refunded to customers
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	34	34
Deferred fuel and purchased power
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	1	16
Other
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	1,109	1,064
AROs – coal ash
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	4,084	4,255
AROs – nuclear and other
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	739	772
Accrued pension and OPEB
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	2,391	2,654
Storm cost deferrals
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	1,399	1,117
Nuclear asset securitized balance, net
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	1,042	1,093
Debt fair value adjustment
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	1,019	1,099
Deferred fuel and purchased power
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	528	838
Deferred asset – Lee and Harris COLA
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	388	426
Hedge costs deferrals
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	356	204
Demand side management (DSM)/Energy Efficiency (EE)
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	343	449
Advanced metering infrastructure (AMI)
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	338	367
Retired generation facilities
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	331	402
Post-in-service carrying costs (PISCC) and deferred operating expenses
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	329	320
Vacation accrual
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	214	213
Derivatives – natural gas supply contracts
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	117	141
Nuclear deferral
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	107	133
Manufactured gas plant (MGP)
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	102	99
Deferred pipeline integrity costs
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	79	65
NCEMPA deferrals
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	72	50
East Bend deferrals
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	44	47
Transmission expansion obligation
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	36	39
Amounts due from customers
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	36	24
Grid Modernization [Member]
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	28	31
Other
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	896	784
Progress Energy
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	7,292	7,701
Regulatory Assets: Current	946	1,137
Other Noncurrent Assets: Regulatory assets	6,346	6,564
Total regulatory liabilities	5,555	5,329
Less: current portion	330	280
Total noncurrent regulatory liabilities	5,225	5,049
Progress Energy | Net regulatory liability related to income taxes
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	2,595	2,710
Progress Energy | Costs of removal
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	2,561	2,135
Progress Energy | Accrued pension and OPEB
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities		149
Progress Energy | Deferred fuel and purchased power
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	1	16
Progress Energy | Other
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	398	319
Progress Energy | AROs – coal ash
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	1,843	2,061
Progress Energy | AROs – nuclear and other
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	668	601
Progress Energy | Accrued pension and OPEB
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	897	1,074
Progress Energy | Storm cost deferrals
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	1,214	953
Progress Energy | Nuclear asset securitized balance, net
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	1,042	1,093
Progress Energy | Deferred fuel and purchased power
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	305	600
Progress Energy | Deferred asset – Lee and Harris COLA
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	38	43
Progress Energy | Hedge costs deferrals
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	129	74
Progress Energy | Demand side management (DSM)/Energy Efficiency (EE)
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	241	256
Progress Energy | Advanced metering infrastructure (AMI)
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	114	127
Progress Energy | Retired generation facilities
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	266	324
Progress Energy | Post-in-service carrying costs (PISCC) and deferred operating expenses
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	33	36
Progress Energy | Vacation accrual
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	41	41
Progress Energy | Nuclear deferral
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	40	46
Progress Energy | NCEMPA deferrals
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	72	50
Progress Energy | Other
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	349	322
Duke Energy Carolinas
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	3,910	3,977
Regulatory Assets: Current	550	520
Other Noncurrent Assets: Regulatory assets	3,360	3,457
Total regulatory liabilities	6,678	6,198
Less: current portion	255	199
Total noncurrent regulatory liabilities	6,423	5,999
Duke Energy Carolinas | Net regulatory liability related to income taxes
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	3,060	3,082
Duke Energy Carolinas | Costs of removal
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	1,936	1,968
Duke Energy Carolinas | AROs – nuclear and other
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	1,100	538
Duke Energy Carolinas | Accrued pension and OPEB
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	39	38
Duke Energy Carolinas | Other
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	543	572
Duke Energy Carolinas | AROs – coal ash
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	1,696	1,725
Duke Energy Carolinas | Accrued pension and OPEB
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	477	581
Duke Energy Carolinas | Storm cost deferrals
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	178	160
Duke Energy Carolinas | Deferred fuel and purchased power
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	222	196
Duke Energy Carolinas | Deferred asset – Lee and Harris COLA
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	350	383
Duke Energy Carolinas | Hedge costs deferrals
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	198	101
Duke Energy Carolinas | Demand side management (DSM)/Energy Efficiency (EE)
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	100	169
Duke Energy Carolinas | Advanced metering infrastructure (AMI)
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	166	176
Duke Energy Carolinas | Retired generation facilities
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	16	21
Duke Energy Carolinas | Post-in-service carrying costs (PISCC) and deferred operating expenses
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	33	34
Duke Energy Carolinas | Vacation accrual
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	80	78
Duke Energy Carolinas | Nuclear deferral
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	67	87
Duke Energy Carolinas | Other
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	327	266
Duke Energy Progress
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	4,678	4,814
Regulatory Assets: Current	526	703
Other Noncurrent Assets: Regulatory assets	4,152	4,111
Total regulatory liabilities	4,468	4,133
Less: current portion	236	178
Total noncurrent regulatory liabilities	4,232	3,955
Duke Energy Progress | Net regulatory liability related to income taxes
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	1,802	1,863
Duke Energy Progress | Costs of removal
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	2,294	1,878
Duke Energy Progress | Accrued pension and OPEB
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities		93
Duke Energy Progress | Other
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	372	299
Duke Energy Progress | AROs – coal ash
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	1,834	2,051
Duke Energy Progress | AROs – nuclear and other
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	509	429
Duke Energy Progress | Accrued pension and OPEB
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	423	542
Duke Energy Progress | Storm cost deferrals
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	801	571
Duke Energy Progress | Deferred fuel and purchased power
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	266	397
Duke Energy Progress | Deferred asset – Lee and Harris COLA
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	38	43
Duke Energy Progress | Hedge costs deferrals
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	85	54
Duke Energy Progress | Demand side management (DSM)/Energy Efficiency (EE)
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	216	235
Duke Energy Progress | Advanced metering infrastructure (AMI)
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	61	67
Duke Energy Progress | Retired generation facilities
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	83	105
Duke Energy Progress | Post-in-service carrying costs (PISCC) and deferred operating expenses
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	33	36
Duke Energy Progress | Vacation accrual
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	41	41
Duke Energy Progress | Nuclear deferral
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	40	46
Duke Energy Progress | NCEMPA deferrals
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	72	50
Duke Energy Progress | Other
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	176	147
Duke Energy Florida
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	2,613	2,888
Regulatory Assets: Current	419	434
Other Noncurrent Assets: Regulatory assets	2,194	2,454
Total regulatory liabilities	1,087	1,196
Less: current portion	94	102
Total noncurrent regulatory liabilities	993	1,094
Duke Energy Florida | Net regulatory liability related to income taxes
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	793	847
Duke Energy Florida | Costs of removal
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	267	257
Duke Energy Florida | Accrued pension and OPEB
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities		56
Duke Energy Florida | Deferred fuel and purchased power
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	1	16
Duke Energy Florida | Other
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	26	20
Duke Energy Florida | AROs – coal ash
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	9	10
Duke Energy Florida | AROs – nuclear and other
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	159	172
Duke Energy Florida | Accrued pension and OPEB
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	474	532
Duke Energy Florida | Storm cost deferrals
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	413	382
Duke Energy Florida | Nuclear asset securitized balance, net
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	1,042	1,093
Duke Energy Florida | Deferred fuel and purchased power
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	39	203
Duke Energy Florida | Hedge costs deferrals
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	44	20
Duke Energy Florida | Demand side management (DSM)/Energy Efficiency (EE)
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	25	21
Duke Energy Florida | Advanced metering infrastructure (AMI)
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	53	60
Duke Energy Florida | Retired generation facilities
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	183	219
Duke Energy Florida | Other
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	172	176
Duke Energy Ohio
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	598	564
Regulatory Assets: Current	49	33
Other Noncurrent Assets: Regulatory assets	549	531
Total regulatory liabilities	827	897
Less: current portion	64	57
Total noncurrent regulatory liabilities	763	840
Duke Energy Ohio | Net regulatory liability related to income taxes
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	654	678
Duke Energy Ohio | Costs of removal
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	86	126
Duke Energy Ohio | Accrued pension and OPEB
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	16	18
Duke Energy Ohio | Other
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	71	75
Duke Energy Ohio | AROs – coal ash
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	16	20
Duke Energy Ohio | Accrued pension and OPEB
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	155	146
Duke Energy Ohio | Storm cost deferrals
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	7	4
Duke Energy Ohio | Deferred fuel and purchased power
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	1	2
Duke Energy Ohio | Hedge costs deferrals
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	6	5
Duke Energy Ohio | Demand side management (DSM)/Energy Efficiency (EE)
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	2	10
Duke Energy Ohio | Advanced metering infrastructure (AMI)
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	40	46
Duke Energy Ohio | Post-in-service carrying costs (PISCC) and deferred operating expenses
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	17	17
Duke Energy Ohio | Vacation accrual
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	5	5
Duke Energy Ohio | Manufactured gas plant (MGP)
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	102	99
Duke Energy Ohio | Deferred pipeline integrity costs
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	17	14
Duke Energy Ohio | East Bend deferrals
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	44	47
Duke Energy Ohio | Transmission expansion obligation
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	40	43
Duke Energy Ohio | Grid Modernization [Member]
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	28	31
Duke Energy Ohio | Other
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	118	75
Duke Energy Indiana
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	1,172	1,157
Regulatory Assets: Current	90	175
Other Noncurrent Assets: Regulatory assets	1,082	982
Total regulatory liabilities	1,740	1,747
Less: current portion	55	25
Total noncurrent regulatory liabilities	1,685	1,722
Duke Energy Indiana | Net regulatory liability related to income taxes
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	1,008	1,009
Duke Energy Indiana | Costs of removal
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	599	628
Duke Energy Indiana | Accrued pension and OPEB
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	90	67
Duke Energy Indiana | Amounts to be refunded to customers
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities		1
Duke Energy Indiana | Other
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	43	42
Duke Energy Indiana | AROs – coal ash
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	529	450
Duke Energy Indiana | Accrued pension and OPEB
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	243	222
Duke Energy Indiana | Deferred fuel and purchased power
Regulatory Assets Liabilities [Line Items]
Total regulatory assets		40
Duke Energy Indiana | Hedge costs deferrals
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	23	24
Duke Energy Indiana | Demand side management (DSM)/Energy Efficiency (EE)
Regulatory Assets Liabilities [Line Items]
Total regulatory assets		14
Duke Energy Indiana | Advanced metering infrastructure (AMI)
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	18	18
Duke Energy Indiana | Retired generation facilities
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	49	57
Duke Energy Indiana | Post-in-service carrying costs (PISCC) and deferred operating expenses
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	246	233
Duke Energy Indiana | Vacation accrual
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	12	11
Duke Energy Indiana | Other
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	52	88
Piedmont
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	363	357
Regulatory Assets: Current	73	54
Other Noncurrent Assets: Regulatory assets	290	303
Total regulatory liabilities	1,212	1,218
Less: current portion	81	37
Total noncurrent regulatory liabilities	1,131	1,181
Piedmont | Net regulatory liability related to income taxes
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	555	579
Piedmont | Costs of removal
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	574	564
Piedmont | Accrued pension and OPEB
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	3	1
Piedmont | Amounts to be refunded to customers
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	34	33
Piedmont | Other
Regulatory Assets Liabilities [Line Items]
Total regulatory liabilities	46	41
Piedmont | AROs – nuclear and other
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	16	19
Piedmont | Accrued pension and OPEB
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	90	99
Piedmont | Vacation accrual
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	12	12
Piedmont | Derivatives – natural gas supply contracts
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	117	141
Piedmont | Deferred pipeline integrity costs
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	62	51
Piedmont | Amounts due from customers
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	36	24
Piedmont | Other
Regulatory Assets Liabilities [Line Items]
Total regulatory assets	$ 30	$ 11