Variable Interest Entities (Schedule of Non-Consolidated VIEs) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates	$ 919	$ 961
Other noncurrent assets	3,715	3,601
Total Assets	163,465	162,388
Other current liabilities	1,858	2,936
Other Noncurrent Liabilities: Other	1,769	1,719
VIE not primary beneficiary
Variable Interest Entities [Line Items]
Other current assets	4
Investments in equity method unconsolidated affiliates	483	530
Other noncurrent assets		31
Deferred tax asset	29
Total Assets	516	561
Other current liabilities	41	933
Other Noncurrent Liabilities: Other	58	18
Total liabilities	99	951
Net assets	417	(390)
Duke Energy Ohio
Variable Interest Entities [Line Items]
Other noncurrent assets	75	72
Total Assets	10,141	10,025
Other current liabilities	67	70
Other Noncurrent Liabilities: Other	97	99
Duke Energy Ohio | VIE not primary beneficiary
Variable Interest Entities [Line Items]
Receivables from affiliated companies	46	83
Total Assets	46	83
Net assets	46	83
Duke Energy Indiana
Variable Interest Entities [Line Items]
Other noncurrent assets	251	253
Total Assets	14,063	14,041
Other current liabilities	82	83
Other Noncurrent Liabilities: Other	35	30
Duke Energy Indiana | VIE not primary beneficiary
Variable Interest Entities [Line Items]
Receivables from affiliated companies	60	110
Total Assets	60	110
Net assets	60	110
Pipeline Investments | VIE not primary beneficiary
Variable Interest Entities [Line Items]
Other current assets	4
Investments in equity method unconsolidated affiliates	3
Other noncurrent assets		31
Deferred tax asset	29
Total Assets	36	31
Other current liabilities	38	928
Other Noncurrent Liabilities: Other	48	8
Total liabilities	86	936
Net assets	(50)	(905)
Commercial Renewables | VIE not primary beneficiary
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates	480	530
Total Assets	480	530
Other current liabilities	3	5
Other Noncurrent Liabilities: Other	10	10
Total liabilities	13	15
Net assets	$ 467	$ 515