Regulatory Matters (Schedule of Regulatory Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Regulatory Assets Liabilities [Line Items]
Regulatory assets	$ 15,622	$ 13,879
Regulatory Assets, Current	2,005	1,437
Regulatory assets, noncurrent	13,617	12,442
Regulatory Liabilities	15,432	15,732
Regulatory Liability, Current	598	402
Regulatory Liability, Noncurrent	14,834	15,330
Costs of Removal [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	5,421	5,968
Asset retirement obligations - nuclear and other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	538	806
Net regulatory liability related to income taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	8,058	8,113
Amounts To Be Refunded to Customers [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	34	10
Storm cost deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities		20
Accrued Pension And OPEB [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	301	146
Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	16	47
Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	1,064	622
Deferred Asset - Lee COLA [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	383
Asset retirement obligations - coal ash [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	4,255	4,025
Asset retirement obligations - nuclear and other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	772	852
Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	2,654	2,249
Retired Generation Facilities [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	445	480
Debt Fair Value Adjustment [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,099	1,197
Storm cost deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,117	531
Nuclear asset securitized balance, net [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,093	1,142
Hedge costs deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	204	234
Derivatives - natural gas supply contracts [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	141	142
Demand Side Management And Energy Efficiency, Asset [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	449	530
Grid Modernization [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	31	39
Vacation accrual [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	213	213
Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	838	507
Nuclear Deferral [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	133	119
Post In Service Carrying Costs And Deferred Operating Expense [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	320	366
Transmission Expansion Obligation [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	39	46
Manufactured Gas Plant [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	99	91
Advanced Metering Infrastructure [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	367	362
NCEMPA deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	50	53
East Bend deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	47	45
Deferred pipeline integrity [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	65	54
Amounts due from customers [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	24	64
Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	784	538
Duke Energy Carolinas [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	3,977	3,152
Regulatory Assets, Current	520	299
Regulatory assets, noncurrent	3,457	2,853
Regulatory Liabilities	6,198	6,357
Regulatory Liability, Current	199	126
Regulatory Liability, Noncurrent	5,999	6,231
Duke Energy Carolinas [Member] | Costs of Removal [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	1,968	2,054
Duke Energy Carolinas [Member] | Asset retirement obligations - nuclear and other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	538	806
Duke Energy Carolinas [Member] | Net regulatory liability related to income taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	3,082	3,028
Duke Energy Carolinas [Member] | Storm cost deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities		20
Duke Energy Carolinas [Member] | Accrued Pension And OPEB [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	38	44
Duke Energy Carolinas [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities		46
Duke Energy Carolinas [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	572	359
Duke Energy Carolinas [Member] | Deferred Asset - Lee COLA [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	383
Duke Energy Carolinas [Member] | Asset retirement obligations - coal ash [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,725	1,645
Duke Energy Carolinas [Member] | Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	581	410
Duke Energy Carolinas [Member] | Retired Generation Facilities [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	21	29
Duke Energy Carolinas [Member] | Storm cost deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	160
Duke Energy Carolinas [Member] | Hedge costs deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	101	109
Duke Energy Carolinas [Member] | Demand Side Management And Energy Efficiency, Asset [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	169	210
Duke Energy Carolinas [Member] | Vacation accrual [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	78	83
Duke Energy Carolinas [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	196	140
Duke Energy Carolinas [Member] | Nuclear Deferral [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	87	84
Duke Energy Carolinas [Member] | Post In Service Carrying Costs And Deferred Operating Expense [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	34	35
Duke Energy Carolinas [Member] | Advanced Metering Infrastructure [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	176	185
Duke Energy Carolinas [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	266	222
Progress Energy [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	7,701	6,751
Regulatory Assets, Current	1,137	741
Regulatory assets, noncurrent	6,564	6,010
Regulatory Liabilities	5,329	5,519
Regulatory Liability, Current	280	213
Regulatory Liability, Noncurrent	5,049	5,306
Progress Energy [Member] | Costs of Removal [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	2,135	2,537
Progress Energy [Member] | Net regulatory liability related to income taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	2,710	2,802
Progress Energy [Member] | Accrued Pension And OPEB [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	149
Progress Energy [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	16	1
Progress Energy [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	319	179
Progress Energy [Member] | Asset retirement obligations - coal ash [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	2,061	1,984
Progress Energy [Member] | Asset retirement obligations - nuclear and other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	601	655
Progress Energy [Member] | Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,074	906
Progress Energy [Member] | Retired Generation Facilities [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	367	386
Progress Energy [Member] | Storm cost deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	953	526
Progress Energy [Member] | Nuclear asset securitized balance, net [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,093	1,142
Progress Energy [Member] | Hedge costs deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	74	94
Progress Energy [Member] | Demand Side Management And Energy Efficiency, Asset [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	256	281
Progress Energy [Member] | Vacation accrual [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	41	42
Progress Energy [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	600	349
Progress Energy [Member] | Nuclear Deferral [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	46	35
Progress Energy [Member] | Post In Service Carrying Costs And Deferred Operating Expense [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	36	38
Progress Energy [Member] | Advanced Metering Infrastructure [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	127	150
Progress Energy [Member] | NCEMPA deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	50	53
Progress Energy [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	322	110
Duke Energy Progress [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	4,814	3,859
Regulatory Assets, Current	703	352
Regulatory assets, noncurrent	4,111	3,507
Regulatory Liabilities	4,133	4,138
Regulatory Liability, Current	178	139
Regulatory Liability, Noncurrent	3,955	3,999
Duke Energy Progress [Member] | Costs of Removal [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	1,878	2,122
Duke Energy Progress [Member] | Net regulatory liability related to income taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	1,863	1,854
Duke Energy Progress [Member] | Accrued Pension And OPEB [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	93
Duke Energy Progress [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities		1
Duke Energy Progress [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	299	161
Duke Energy Progress [Member] | Asset retirement obligations - coal ash [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	2,051	1,975
Duke Energy Progress [Member] | Asset retirement obligations - nuclear and other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	429	359
Duke Energy Progress [Member] | Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	542	430
Duke Energy Progress [Member] | Retired Generation Facilities [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	148	170
Duke Energy Progress [Member] | Storm cost deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	571	150
Duke Energy Progress [Member] | Hedge costs deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	54	64
Duke Energy Progress [Member] | Demand Side Management And Energy Efficiency, Asset [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	235	264
Duke Energy Progress [Member] | Vacation accrual [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	41	42
Duke Energy Progress [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	397	130
Duke Energy Progress [Member] | Nuclear Deferral [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	46	35
Duke Energy Progress [Member] | Post In Service Carrying Costs And Deferred Operating Expense [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	36	38
Duke Energy Progress [Member] | Advanced Metering Infrastructure [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	67	75
Duke Energy Progress [Member] | NCEMPA deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	50	53
Duke Energy Progress [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	147	74
Duke Energy Florida [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	2,888	2,892
Regulatory Assets, Current	434	389
Regulatory assets, noncurrent	2,454	2,503
Regulatory Liabilities	1,196	1,381
Regulatory Liability, Current	102	74
Regulatory Liability, Noncurrent	1,094	1,307
Duke Energy Florida [Member] | Costs of Removal [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	257	415
Duke Energy Florida [Member] | Net regulatory liability related to income taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	847	948
Duke Energy Florida [Member] | Accrued Pension And OPEB [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	56
Duke Energy Florida [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	16
Duke Energy Florida [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	20	18
Duke Energy Florida [Member] | Asset retirement obligations - coal ash [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	10	9
Duke Energy Florida [Member] | Asset retirement obligations - nuclear and other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	172	296
Duke Energy Florida [Member] | Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	532	476
Duke Energy Florida [Member] | Retired Generation Facilities [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	219	216
Duke Energy Florida [Member] | Storm cost deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	382	376
Duke Energy Florida [Member] | Nuclear asset securitized balance, net [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,093	1,142
Duke Energy Florida [Member] | Hedge costs deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	20	30
Duke Energy Florida [Member] | Demand Side Management And Energy Efficiency, Asset [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	21	17
Duke Energy Florida [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	203	219
Duke Energy Florida [Member] | Advanced Metering Infrastructure [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	60	75
Duke Energy Florida [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	176	36
Duke Energy Ohio [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	564	494
Regulatory Assets, Current	33	49
Regulatory assets, noncurrent	531	445
Regulatory Liabilities	897	927
Regulatory Liability, Current	57	36
Regulatory Liability, Noncurrent	840	891
Duke Energy Ohio [Member] | Costs of Removal [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	126	189
Duke Energy Ohio [Member] | Net regulatory liability related to income taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	678	688
Duke Energy Ohio [Member] | Accrued Pension And OPEB [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	18	16
Duke Energy Ohio [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	75	34
Duke Energy Ohio [Member] | Asset retirement obligations - coal ash [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	20	17
Duke Energy Ohio [Member] | Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	146	139
Duke Energy Ohio [Member] | Storm cost deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	4	5
Duke Energy Ohio [Member] | Hedge costs deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	5	6
Duke Energy Ohio [Member] | Demand Side Management And Energy Efficiency, Asset [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	10	18
Duke Energy Ohio [Member] | Grid Modernization [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	31	39
Duke Energy Ohio [Member] | Vacation accrual [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	5	5
Duke Energy Ohio [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	2
Duke Energy Ohio [Member] | Post In Service Carrying Costs And Deferred Operating Expense [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	17	19
Duke Energy Ohio [Member] | Transmission Expansion Obligation [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	43	50
Duke Energy Ohio [Member] | Manufactured Gas Plant [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	99	91
Duke Energy Ohio [Member] | Advanced Metering Infrastructure [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	46	6
Duke Energy Ohio [Member] | East Bend deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	47	45
Duke Energy Ohio [Member] | Deferred pipeline integrity [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	14	12
Duke Energy Ohio [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	75	42
Duke Energy Indiana [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,157	1,143
Regulatory Assets, Current	175	165
Regulatory assets, noncurrent	982	978
Regulatory Liabilities	1,747	1,747
Regulatory Liability, Current	25	24
Regulatory Liability, Noncurrent	1,722	1,723
Duke Energy Indiana [Member] | Costs of Removal [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	628	644
Duke Energy Indiana [Member] | Net regulatory liability related to income taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	1,009	998
Duke Energy Indiana [Member] | Amounts To Be Refunded to Customers [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	1	10
Duke Energy Indiana [Member] | Accrued Pension And OPEB [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	67	64
Duke Energy Indiana [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	42	31
Duke Energy Indiana [Member] | Asset retirement obligations - coal ash [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	450	380
Duke Energy Indiana [Member] | Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	222	197
Duke Energy Indiana [Member] | Retired Generation Facilities [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	57	65
Duke Energy Indiana [Member] | Hedge costs deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	24	25
Duke Energy Indiana [Member] | Demand Side Management And Energy Efficiency, Asset [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	14	21
Duke Energy Indiana [Member] | Vacation accrual [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	11	11
Duke Energy Indiana [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	40	18
Duke Energy Indiana [Member] | Post In Service Carrying Costs And Deferred Operating Expense [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	233	274
Duke Energy Indiana [Member] | Advanced Metering Infrastructure [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	18	21
Duke Energy Indiana [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	88	131
Piedmont Natural Gas [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	357	378
Regulatory Assets, Current	54	95
Regulatory assets, noncurrent	303	283
Regulatory Liabilities	1,218	1,144
Regulatory Liability, Current	37	3
Regulatory Liability, Noncurrent	1,181	1,141
Piedmont Natural Gas [Member] | Costs of Removal [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	564	544
Piedmont Natural Gas [Member] | Net regulatory liability related to income taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	579	597
Piedmont Natural Gas [Member] | Amounts To Be Refunded to Customers [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	33
Piedmont Natural Gas [Member] | Accrued Pension And OPEB [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	1
Piedmont Natural Gas [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory Liabilities	41	3
Piedmont Natural Gas [Member] | Asset retirement obligations - nuclear and other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	19	15
Piedmont Natural Gas [Member] | Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	99	91
Piedmont Natural Gas [Member] | Derivatives - natural gas supply contracts [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	141	142
Piedmont Natural Gas [Member] | Vacation accrual [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	12	10
Piedmont Natural Gas [Member] | Deferred pipeline integrity [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	51	42
Piedmont Natural Gas [Member] | Amounts due from customers [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	24	64
Piedmont Natural Gas [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	11	$ 14
Hurricane Michael Storm Damage [Member] | Duke Energy Florida [Member] | Storm cost deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	$ 165