Variable Interest Entities (Schedule of Consolidated VIEs) (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Variable Interest Entities [Line Items]
Regulatory Assets: Current	$ 1,774	$ 1,796
Current Assets: Other	1,031	764
Other Noncurrent Assets: Regulatory assets	13,285	13,222
Property, Plant and Equipment: Cost	151,592	147,654
Accumulated depreciation and amortization	(47,295)	(45,773)
Other Noncurrent Assets: Other	3,458	3,289
Current Liabilities: Other	2,898	2,367
Current maturities of long-term debt	3,756	3,141
Long-Term Debt	56,143	54,985
Other Noncurrent Liabilities: AROs	12,539	12,437
Other Noncurrent Liabilities: Other	1,563	1,581
Duke Energy Florida
Variable Interest Entities [Line Items]
Regulatory Assets: Current	432	419
Current Assets: Other	44	58
Other Noncurrent Assets: Regulatory assets	1,860	2,194
Property, Plant and Equipment: Cost	21,290	20,457
Accumulated depreciation and amortization	(5,394)	(5,236)
Other Noncurrent Assets: Other	327	311
Current Liabilities: Other	372	415
Current maturities of long-term debt	323	571
Long-Term Debt	7,628	7,416
Other Noncurrent Liabilities: AROs	581	578
Other Noncurrent Liabilities: Other	194	136
DEFPF | Duke Energy Florida | VIE primary beneficiary
Variable Interest Entities [Line Items]
Receivables of VIEs	6	5
Regulatory Assets: Current	53	52
Current Assets: Other	32	39
Other Noncurrent Assets: Regulatory assets	969	989
Current Liabilities: Other	10	10
Current maturities of long-term debt	54	54
Long-Term Debt	1,028	1,057
Commercial Renewables | VIE primary beneficiary
Variable Interest Entities [Line Items]
Current Assets: Other	228	203
Property, Plant and Equipment: Cost	6,198	5,747
Accumulated depreciation and amortization	(1,145)	(1,041)
Other Noncurrent Assets: Other	75	106
Current maturities of long-term debt	158	162
Long-Term Debt	1,457	1,541
Other Noncurrent Liabilities: AROs	144	127
Other Noncurrent Liabilities: Other	$ 251	$ 228