Variable Interest Entities (Schedule of Consolidated VIEs) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory Assets: Current	$ 1,770	$ 1,796
Current Assets: Other	1,000	764
Other Noncurrent Assets: Regulatory assets	13,413	13,222
Property, Plant and Equipment: Cost	149,676	147,654
Accumulated depreciation and amortization	(46,599)	(45,773)
Other Noncurrent Assets: Other	3,315	3,289
Current Liabilities: Other	2,004	2,367
Current maturities of long-term debt	5,077	3,141
Long-Term Debt	56,311	54,985
Other Noncurrent Liabilities: AROs	12,497	12,437
Other Noncurrent Liabilities: Other	1,669	1,581
Duke Energy Carolinas
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory Assets: Current	524	550
Current Assets: Other	31	21
Other Noncurrent Assets: Regulatory assets	3,427	3,360
Property, Plant and Equipment: Cost	49,534	48,922
Accumulated depreciation and amortization	(16,884)	(16,525)
Other Noncurrent Assets: Other	1,136	1,149
Current Liabilities: Other	479	611
Current maturities of long-term debt	457	458
Long-Term Debt	12,050	11,142
Other Noncurrent Liabilities: AROs	5,552	5,528
Other Noncurrent Liabilities: Other	640	627
Duke Energy Progress
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory Assets: Current	503	526
Current Assets: Other	48	60
Other Noncurrent Assets: Regulatory assets	4,392	4,152
Property, Plant and Equipment: Cost	34,898	34,603
Accumulated depreciation and amortization	(12,114)	(11,915)
Other Noncurrent Assets: Other	682	651
Current Liabilities: Other	429	478
Current maturities of long-term debt	1,006	1,006
Long-Term Debt	7,903	7,902
Other Noncurrent Liabilities: AROs	5,442	5,408
Other Noncurrent Liabilities: Other	83	92
Duke Energy Florida
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory Assets: Current	451	419
Current Assets: Other	37	58
Other Noncurrent Assets: Regulatory assets	2,097	2,194
Property, Plant and Equipment: Cost	20,880	20,457
Accumulated depreciation and amortization	(5,339)	(5,236)
Other Noncurrent Assets: Other	329	311
Current Liabilities: Other	383	415
Current maturities of long-term debt	322	571
Long-Term Debt	7,384	7,416
Other Noncurrent Liabilities: AROs	578	578
Other Noncurrent Liabilities: Other	169	136
DEFPF | Duke Energy Florida | VIE primary beneficiary
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	4	5
Regulatory Assets: Current	53	52
Current Assets: Other	13	39
Other Noncurrent Assets: Regulatory assets	980	989
Current Liabilities: Other	2	10
Current maturities of long-term debt	54	54
Long-Term Debt	1,028	1,057
DERF | Duke Energy Carolinas | VIE primary beneficiary
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	616	642
Long-Term Debt	475	474
DEPR | Duke Energy Progress | VIE primary beneficiary
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	410	489
Long-Term Debt	325	325
DEFR | Duke Energy Florida | VIE primary beneficiary
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	331	336
Long-Term Debt	250	250
CRC | VIE primary beneficiary
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	467	522
Long-Term Debt	350	350
Commercial Renewables | VIE primary beneficiary
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Current Assets: Other	287	203
Property, Plant and Equipment: Cost	6,106	5,747
Accumulated depreciation and amortization	(1,094)	(1,041)
Other Noncurrent Assets: Other	82	106
Current maturities of long-term debt	162	162
Long-Term Debt	1,538	1,541
Other Noncurrent Liabilities: AROs	129	127
Other Noncurrent Liabilities: Other	$ 258	$ 228