Variable Interest Entities (Schedule of Non-Consolidated VIEs) (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates	$ 861	$ 1,936
Total Assets	160,049	158,838
Taxes accrued	657	392
Current Liabilities: Other	2,898	2,367
Deferred income taxes	8,979	8,878
Other Noncurrent Liabilities: Other	1,563	1,581
VIE not primary beneficiary
Variable Interest Entities [Line Items]
Receivables from affiliated companies	(1)	(1)
Investments in equity method unconsolidated affiliates	414	1,479
Deferred tax asset	439
Total Assets	852	1,478
Taxes accrued	9	(1)
Current Liabilities: Other	924	4
Deferred income taxes		59
Other Noncurrent Liabilities: Other	10	11
Total liabilities	943	73
Net assets	(91)	1,405
Pipeline Investments | VIE not primary beneficiary
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates		1,179
Deferred tax asset	439
Total Assets	439	1,179
Taxes accrued	9	(1)
Current Liabilities: Other	920
Deferred income taxes		59
Total liabilities	929	58
Net assets	(490)	1,121
Commercial Renewables | VIE not primary beneficiary
Variable Interest Entities [Line Items]
Receivables from affiliated companies	(1)	(1)
Investments in equity method unconsolidated affiliates	413	300
Total Assets	412	299
Net assets	412	299
Other VIEs | VIE not primary beneficiary
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates	1
Total Assets	1
Current Liabilities: Other	4	4
Other Noncurrent Liabilities: Other	10	11
Total liabilities	14	15
Net assets	(13)	(15)
Duke Energy Ohio
Variable Interest Entities [Line Items]
Receivables from affiliated companies	47	92
Total Assets	9,609	9,338
Taxes accrued	210	219
Current Liabilities: Other	71	75
Deferred income taxes	958	922
Other Noncurrent Liabilities: Other	96	94
Duke Energy Ohio | VIE not primary beneficiary
Variable Interest Entities [Line Items]
Receivables from affiliated companies	34	64
Total Assets	34	64
Net assets	34	64
Duke Energy Indiana
Variable Interest Entities [Line Items]
Receivables from affiliated companies	59	79
Total Assets	13,852	13,276
Taxes accrued	46	49
Current Liabilities: Other	104	112
Deferred income taxes	1,195	1,150
Other Noncurrent Liabilities: Other	12	18
Duke Energy Indiana | VIE not primary beneficiary
Variable Interest Entities [Line Items]
Receivables from affiliated companies	49	77
Total Assets	49	77
Net assets	$ 49	$ 77