Variable Interest Entities (Consolidated VIEs) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory Assets: Current	$ 1,796	$ 2,005
Current Assets: Other	764	1,049
Property, Plant and Equipment: Cost	147,654	134,458
Accumulated depreciation and amortization	(45,773)	(43,126)
Other Noncurrent Assets: Regulatory assets	13,222	13,617
Other Noncurrent Assets: Other	3,289	2,935
Current Liabilities: Other	2,367	2,085
Current maturities of long-term debt	3,141	3,406
Long-Term Debt	54,985	51,123
Asset retirement obligations	12,437	9,548
Other Noncurrent Liabilities: Other	1,581	1,650
Duke Energy Florida
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory Assets: Current	419	434
Current Assets: Other	58	46
Property, Plant and Equipment: Cost	20,457	18,792
Accumulated depreciation and amortization	(5,236)	(4,968)
Other Noncurrent Assets: Regulatory assets	2,194	2,454
Other Noncurrent Assets: Other	311	311
Current Liabilities: Other	415	406
Current maturities of long-term debt	571	270
Long-Term Debt	7,416	7,051
Asset retirement obligations	578	586
Other Noncurrent Liabilities: Other	136	93
DEFPF \| Duke Energy Florida \| VIE
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	5	5
Regulatory Assets: Current	52	52
Current Assets: Other	39	39
Other Noncurrent Assets: Regulatory assets	989	1,041
Current Liabilities: Other	10	10
Current maturities of long-term debt	54	53
Long-Term Debt	1,057	1,111
Commercial Renewables \| VIE
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Current Assets: Other	203	123
Property, Plant and Equipment: Cost	5,747	4,007
Accumulated depreciation and amortization	(1,041)	(698)
Other Noncurrent Assets: Other	106	261
Current maturities of long-term debt	162	174
Long-Term Debt	1,541	1,587
Asset retirement obligations	127	106
Other Noncurrent Liabilities: Other	$ 228	$ 212

The amount owed to the reporting entity by counterparties in securitized loan transactions.

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Noncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

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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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Period end book value of accumulated depreciation on property, plant and equipment (PPE) that is owned by the regulated operations of the public utility.

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Period end amount of total gross PPE.

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Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are expected to be recovered through revenue sources within one year or the normal operating cycle, if longer. Such costs are capitalized if they meet both of the following criteria: a. It is probable that future revenue in an amount at least equal to the capitalized cost will result from inclusion of that cost in allowable costs for rate-making purposes. b. Based on available evidence, the future revenue will be provided to permit recovery of the previously incurred cost rather than to provide for expected levels of similar future costs. If the revenue will be provided through an automatic rate-adjustment clause, this criterion requires that the regulator's intent clearly be to permit recovery of the previously incurred cost.

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