Variable Interest Entities (Consolidated VIEs) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory Assets, Current	$ 2,005	$ 1,437
Other current assets	1,049	634
Property, plant and equipment, cost	134,458	127,507
Accumulated depreciation and amortization	(43,126)	(41,537)
Regulatory assets, noncurrent	13,617	12,442
Investments and other assets	2,935	2,960
Current maturities of long-term debt	3,406	3,244
Other current liabilities	2,085	1,865
Long-Term debt	51,123	49,035
Deferred income taxes	(7,806)	(6,621)
Asset retirement obligations	9,548	9,486
Other Liabilities	1,650	1,581
Duke Energy Carolinas [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory Assets, Current	520	299
Other current assets	72	19
Property, plant and equipment, cost	44,741	42,939
Accumulated depreciation and amortization	(15,496)	(15,063)
Regulatory assets, noncurrent	3,457	2,853
Investments and other assets	1,027	979
Current maturities of long-term debt	6	1,205
Other current liabilities	571	486
Long-Term debt	10,633	8,598
Deferred income taxes	(3,689)	(3,413)
Asset retirement obligations	3,659	3,273
Other Liabilities	671	566
Duke Energy Progress [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory Assets, Current	703	352
Other current assets	62	97
Property, plant and equipment, cost	31,459	29,583
Accumulated depreciation and amortization	(11,423)	(10,903)
Regulatory assets, noncurrent	4,111	3,507
Investments and other assets	612	599
Current maturities of long-term debt	603	3
Other current liabilities	408	376
Long-Term debt	7,451	7,204
Deferred income taxes	(2,119)	(1,883)
Asset retirement obligations	4,311	4,378
Other Liabilities	106	45
Duke Energy Florida [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory Assets, Current	434	389
Other current assets	46	86
Property, plant and equipment, cost	18,792	17,730
Accumulated depreciation and amortization	(4,968)	(4,947)
Regulatory assets, noncurrent	2,454	2,503
Investments and other assets	311	284
Current maturities of long-term debt	270	768
Other current liabilities	406	334
Long-Term debt	7,051	6,327
Deferred income taxes	(1,986)	(1,761)
Asset retirement obligations	586	742
Other Liabilities	93	108
DEFPF [Member] \| Duke Energy Florida [Member] \| Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Restricted receivables of VIEs	5	4
Regulatory Assets, Current	52	51
Other current assets	39	40
Regulatory assets, noncurrent	1,041	1,091
Current maturities of long-term debt	53	53
Other current liabilities	10	10
Long-Term debt	1,111	1,164
DERF [Member] \| Duke Energy Carolinas [Member] \| Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Restricted receivables of VIEs	699	640
Long-Term debt	450	450
DEPR [Member] \| Duke Energy Progress [Member] \| Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Restricted receivables of VIEs	547	459
Long-Term debt	300	300
DEFR [Member] \| Duke Energy Florida [Member] \| Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Restricted receivables of VIEs	357	317
Long-Term debt	225	225
Cinergy Receivables [Member] \| Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Restricted receivables of VIEs	564	545
Long-Term debt	325	325
Commercial Renewables [Member] \| Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Other current assets	123	174
Property, plant and equipment, cost	4,007	3,923
Accumulated depreciation and amortization	(698)	(591)
Investments and other assets	261	50
Current maturities of long-term debt	174	170
Long-Term debt	1,587	1,700
Deferred income taxes		(148)
Asset retirement obligations	106	83
Other Liabilities	$ 212	$ 241

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Amount of asset related to consideration paid in advance for costs that provide economic benefits in future periods, and amount of other assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer.

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