Regulatory Matters (Schedule of Regulatory Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Regulatory Assets Liabilities [Line Items]
Regulatory assets	$ 13,901	$ 12,250
Regulatory Assets, Current	1,023	877
Regulatory Assets, noncurrent	12,878	11,373
Regulatory liabilities	7,290	6,655
Regulatory liabilities - current	409	400
Regulatory liabilities, noncurrent	6,881	6,255
Costs of Removal [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	6,074	5,329
Amounts To Be Refunded to Customers [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	45	71
Storm Reserve [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	83	150
Accrued Pension And OPEB [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	174	288
Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	192	311
Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	722	506
Asset retirement obligations - coal ash [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	3,761	2,555
Asset retirement obligations - nuclear and other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	684	838
Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	2,387	2,151
Retired Generation Facilities [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	534	509
Debt Fair Value Adjustment [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,313	1,191
Net Regulatory Asset Related To Income Taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	894	1,075
Storm Costs Deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	153
Nuclear asset securitizable balance, net [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,193	1,237
Hedge Cost and Other Deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	217	571
Derivatives - gas supply contracts [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	187
Demand Side Management And Energy Efficiency [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	407	340
Grid Modernization [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	65	68
Vacation Accrual [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	196	192
Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	156	151
Nuclear Deferral [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	226	245
Post-In-Service Carrying Costs And Deferred Operating Expense [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	413	383
Gasification Services Agreement Buyout Costs [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	8	32
Transmission Expansion Obligation [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	71	72
Manufactured Gas Plant [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	99	104
Advanced Metering Infrastructure [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	218
NCEMPA deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	51	21
East Bend deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	32	16
Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	636	499
Duke Energy Carolinas [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	3,397	3,071
Regulatory Assets, Current	238	305
Regulatory Assets, noncurrent	3,159	2,766
Regulatory liabilities	3,001	2,841
Regulatory liabilities - current	161	39
Regulatory liabilities, noncurrent	2,840	2,802
Duke Energy Carolinas [Member] | Costs of Removal [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	2,476	2,413
Duke Energy Carolinas [Member] | Storm Reserve [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	22	24
Duke Energy Carolinas [Member] | Accrued Pension And OPEB [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	46	68
Duke Energy Carolinas [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	105	55
Duke Energy Carolinas [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	352	281
Duke Energy Carolinas [Member] | Asset retirement obligations - coal ash [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,536	1,120
Duke Energy Carolinas [Member] | Asset retirement obligations - nuclear and other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	9	104
Duke Energy Carolinas [Member] | Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	481	479
Duke Energy Carolinas [Member] | Retired Generation Facilities [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	39	49
Duke Energy Carolinas [Member] | Net Regulatory Asset Related To Income Taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	484	564
Duke Energy Carolinas [Member] | Hedge Cost and Other Deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	93	127
Duke Energy Carolinas [Member] | Demand Side Management And Energy Efficiency [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	122	80
Duke Energy Carolinas [Member] | Vacation Accrual [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	76	79
Duke Energy Carolinas [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets		21
Duke Energy Carolinas [Member] | Nuclear Deferral [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	92	107
Duke Energy Carolinas [Member] | Post-In-Service Carrying Costs And Deferred Operating Expense [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	70	97
Duke Energy Carolinas [Member] | Advanced Metering Infrastructure [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	172
Duke Energy Carolinas [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	223	244
Progress Energy [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	6,123	5,797
Regulatory Assets, Current	401	362
Regulatory Assets, noncurrent	5,722	5,435
Regulatory liabilities	2,584	2,673
Regulatory liabilities - current	189	286
Regulatory liabilities, noncurrent	2,395	2,387
Progress Energy [Member] | Costs of Removal [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	2,198	2,078
Progress Energy [Member] | Storm Reserve [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	60	125
Progress Energy [Member] | Accrued Pension And OPEB [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities		51
Progress Energy [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	81	255
Progress Energy [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	245	164
Progress Energy [Member] | Asset retirement obligations - coal ash [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,830	1,394
Progress Energy [Member] | Asset retirement obligations - nuclear and other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	569	487
Progress Energy [Member] | Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	882	807
Progress Energy [Member] | Retired Generation Facilities [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	422	409
Progress Energy [Member] | Net Regulatory Asset Related To Income Taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	231	318
Progress Energy [Member] | Storm Costs Deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	148
Progress Energy [Member] | Nuclear asset securitizable balance, net [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,193	1,237
Progress Energy [Member] | Hedge Cost and Other Deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	91	410
Progress Energy [Member] | Demand Side Management And Energy Efficiency [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	278	250
Progress Energy [Member] | Vacation Accrual [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	38	38
Progress Energy [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	111	129
Progress Energy [Member] | Nuclear Deferral [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	134	138
Progress Energy [Member] | Post-In-Service Carrying Costs And Deferred Operating Expense [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	42	38
Progress Energy [Member] | NCEMPA deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	51	21
Progress Energy [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	103	121
Duke Energy Progress [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	3,431	2,974
Regulatory Assets, Current	188	264
Regulatory Assets, noncurrent	3,243	2,710
Regulatory liabilities	2,104	1,963
Regulatory liabilities - current	158	85
Regulatory liabilities, noncurrent	1,946	1,878
Duke Energy Progress [Member] | Costs of Removal [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	1,840	1,725
Duke Energy Progress [Member] | Accrued Pension And OPEB [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities		25
Duke Energy Progress [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	64	58
Duke Energy Progress [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	200	155
Duke Energy Progress [Member] | Asset retirement obligations - coal ash [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,822	1,386
Duke Energy Progress [Member] | Asset retirement obligations - nuclear and other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	275	195
Duke Energy Progress [Member] | Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	423	366
Duke Energy Progress [Member] | Retired Generation Facilities [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	165	179
Duke Energy Progress [Member] | Net Regulatory Asset Related To Income Taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	7	106
Duke Energy Progress [Member] | Storm Costs Deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	148
Duke Energy Progress [Member] | Hedge Cost and Other Deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	66	171
Duke Energy Progress [Member] | Demand Side Management And Energy Efficiency [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	263	237
Duke Energy Progress [Member] | Vacation Accrual [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	38	38
Duke Energy Progress [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	24	93
Duke Energy Progress [Member] | Nuclear Deferral [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	38	62
Duke Energy Progress [Member] | Post-In-Service Carrying Costs And Deferred Operating Expense [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	42	38
Duke Energy Progress [Member] | NCEMPA deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	51	21
Duke Energy Progress [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	69	82
Duke Energy Florida [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	2,693	2,823
Regulatory Assets, Current	213	98
Regulatory Assets, noncurrent	2,480	2,725
Regulatory liabilities	479	709
Regulatory liabilities - current	31	200
Regulatory liabilities, noncurrent	448	509
Duke Energy Florida [Member] | Costs of Removal [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	358	353
Duke Energy Florida [Member] | Storm Reserve [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	60	125
Duke Energy Florida [Member] | Accrued Pension And OPEB [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities		26
Duke Energy Florida [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	17	197
Duke Energy Florida [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	44	8
Duke Energy Florida [Member] | Asset retirement obligations - coal ash [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	8	8
Duke Energy Florida [Member] | Asset retirement obligations - nuclear and other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	294	292
Duke Energy Florida [Member] | Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	458	441
Duke Energy Florida [Member] | Retired Generation Facilities [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	257	230
Duke Energy Florida [Member] | Net Regulatory Asset Related To Income Taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	224	212
Duke Energy Florida [Member] | Nuclear asset securitizable balance, net [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,193	1,237
Duke Energy Florida [Member] | Hedge Cost and Other Deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	25	239
Duke Energy Florida [Member] | Demand Side Management And Energy Efficiency [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	15	13
Duke Energy Florida [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	87	36
Duke Energy Florida [Member] | Nuclear Deferral [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	96	76
Duke Energy Florida [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	36	39
Duke Energy Ohio [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	557	533
Regulatory Assets, Current	37	36
Regulatory Assets, noncurrent	520	497
Regulatory liabilities	257	257
Regulatory liabilities - current	21	12
Regulatory liabilities, noncurrent	236	245
Duke Energy Ohio [Member] | Costs of Removal [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	212	222
Duke Energy Ohio [Member] | Storm Reserve [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	1	1
Duke Energy Ohio [Member] | Accrued Pension And OPEB [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	19	21
Duke Energy Ohio [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	6	1
Duke Energy Ohio [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	19	12
Duke Energy Ohio [Member] | Asset retirement obligations - coal ash [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	12	4
Duke Energy Ohio [Member] | Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	135	139
Duke Energy Ohio [Member] | Net Regulatory Asset Related To Income Taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	63	55
Duke Energy Ohio [Member] | Storm Costs Deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	5
Duke Energy Ohio [Member] | Hedge Cost and Other Deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	7	7
Duke Energy Ohio [Member] | Demand Side Management And Energy Efficiency [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	6	10
Duke Energy Ohio [Member] | Grid Modernization [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	65	68
Duke Energy Ohio [Member] | Vacation Accrual [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	4	5
Duke Energy Ohio [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	5	1
Duke Energy Ohio [Member] | Post-In-Service Carrying Costs And Deferred Operating Expense [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	20	21
Duke Energy Ohio [Member] | Transmission Expansion Obligation [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	71	72
Duke Energy Ohio [Member] | Manufactured Gas Plant [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	99	104
Duke Energy Ohio [Member] | East Bend deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	32	16
Duke Energy Ohio [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	33	31
Duke Energy Indiana [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,222	818
Regulatory Assets, Current	149	102
Regulatory Assets, noncurrent	1,073	716
Regulatory liabilities	788	816
Regulatory liabilities - current	40	62
Regulatory liabilities, noncurrent	748	754
Duke Energy Indiana [Member] | Costs of Removal [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	660	616
Duke Energy Indiana [Member] | Amounts To Be Refunded to Customers [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	45	71
Duke Energy Indiana [Member] | Accrued Pension And OPEB [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	72	83
Duke Energy Indiana [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	11	46
Duke Energy Indiana [Member] | Asset retirement obligations - coal ash [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	276	37
Duke Energy Indiana [Member] | Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	222	220
Duke Energy Indiana [Member] | Retired Generation Facilities [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	73	51
Duke Energy Indiana [Member] | Net Regulatory Asset Related To Income Taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	119	120
Duke Energy Indiana [Member] | Hedge Cost and Other Deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	26	27
Duke Energy Indiana [Member] | Vacation Accrual [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	10	10
Duke Energy Indiana [Member] | Deferred Fuel and Purchased Power [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	40
Duke Energy Indiana [Member] | Post-In-Service Carrying Costs And Deferred Operating Expense [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	281	227
Duke Energy Indiana [Member] | Gasification Services Agreement Buyout Costs [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	8	32
Duke Energy Indiana [Member] | Advanced Metering Infrastructure [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	46
Duke Energy Indiana [Member] | Other [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	$ 121	$ 94