Income Taxes (Deferred Income Taxes) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities	$ 347	$ 286
Lease obligations	346	515
Pension, post-retirement and other employee benefits	207	236
Progress Energy merger purchase accounting adjustments	340	441
Tax credits and NOL carryforwards	3,784	3,909
Other	85	93
Valuation allowance	(518)	(586)
Total deferred income tax assets	4,591	4,894
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets	(2,428)	(2,267)
Accelerated depreciation rates	(10,391)	(10,729)
Regulatory assets and deferred debits, net	(1,151)	(1,142)
Total deferred income tax liabilities	(13,970)	(14,138)
Net deferred income tax liabilities	(9,379)	(9,244)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	3,784	3,909
Valuation allowance	518	586
General Business Credits
Deferred Tax Assets, Gross [Abstract]
Tax credits and NOL carryforwards	2,312
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	2,312
NOL Carryforwards | Federal
Deferred Tax Assets, Gross [Abstract]
Tax credits and NOL carryforwards	4
Valuation allowance	(4)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	4
Valuation allowance	4
NOL Carryforwards | State
Deferred Tax Assets, Gross [Abstract]
Tax credits and NOL carryforwards	328
Valuation allowance	(112)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	328
Valuation allowance	112
NOL Carryforwards | Foreign
Deferred Tax Assets, Gross [Abstract]
Tax credits and NOL carryforwards	12
Valuation allowance	(12)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	12
Valuation allowance	12
Foreign Tax Credit
Deferred Tax Assets, Gross [Abstract]
Valuation allowance	(390)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Valuation allowance	390
Foreign Tax Credit | Foreign
Deferred Tax Assets, Gross [Abstract]
Tax credits and NOL carryforwards	1,128
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	1,128
Duke Energy Carolinas
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities	121	85
Lease obligations	91	96
Pension, post-retirement and other employee benefits	(36)	(30)
Tax credits and NOL carryforwards	349	285
Regulatory liabilities and deferred credits	11	11
Other	12	8
Total deferred income tax assets	548	455
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets	(1,205)	(1,127)
Accelerated depreciation rates	(2,977)	(3,170)
Total deferred income tax liabilities	(4,182)	(4,297)
Net deferred income tax liabilities	(3,634)	(3,842)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	349	285
Progress Energy
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities	101	87
Lease obligations	197	208
Pension, post-retirement and other employee benefits	30	68
Tax credits and NOL carryforwards	497	508
Other	12	14
Total deferred income tax assets	837	885
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets	(742)	(669)
Accelerated depreciation rates	(3,891)	(3,868)
Regulatory assets and deferred debits, net	(768)	(744)
Total deferred income tax liabilities	(5,401)	(5,281)
Net deferred income tax liabilities	(4,564)	(4,396)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	497	508
Duke Energy Progress
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities	60	67
Lease obligations	121	120
Pension, post-retirement and other employee benefits	17	24
Tax credits and NOL carryforwards	160	179
Other	7	9
Total deferred income tax assets	365	399
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets	(610)	(507)
Accelerated depreciation rates	(1,546)	(1,778)
Regulatory assets and deferred debits, net	(417)	(412)
Total deferred income tax liabilities	(2,573)	(2,697)
Net deferred income tax liabilities	(2,208)	(2,298)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	160	179
Duke Energy Florida
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities	40	18
Lease obligations	76	87
Pension, post-retirement and other employee benefits	7	38
Tax credits and NOL carryforwards	306	282
Other	4	4
Total deferred income tax assets	433	429
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets	(135)	(164)
Accelerated depreciation rates	(2,382)	(2,124)
Regulatory assets and deferred debits, net	(350)	(332)
Total deferred income tax liabilities	(2,867)	(2,620)
Net deferred income tax liabilities	(2,434)	(2,191)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	306	282
Duke Energy Ohio
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities	19	21
Lease obligations	4	5
Pension, post-retirement and other employee benefits	11	16
Tax credits and NOL carryforwards	13	16
Regulatory liabilities and deferred credits	16	18
Investments and other assets	5	7
Other	7	7
Total deferred income tax assets	75	90
Deferred Tax Liabilities, Gross [Abstract]
Accelerated depreciation rates	(1,125)	(1,071)
Total deferred income tax liabilities	(1,125)	(1,071)
Net deferred income tax liabilities	(1,050)	(981)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	13	16
Duke Energy Indiana
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities	7	7
Lease obligations	16	16
Pension, post-retirement and other employee benefits	20	26
Tax credits and NOL carryforwards	195	183
Investments and other assets	6
Other	2	1
Total deferred income tax assets	246	233
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets		(14)
Accelerated depreciation rates	(1,496)	(1,433)
Regulatory assets and deferred debits, net	(53)	(14)
Total deferred income tax liabilities	(1,549)	(1,461)
Net deferred income tax liabilities	(1,303)	(1,228)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	195	183
Piedmont
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities	18	38
Lease obligations	4	5
Pension, post-retirement and other employee benefits	(8)	(5)
Tax credits and NOL carryforwards	29	29
Regulatory liabilities and deferred credits	6
Other	8	8
Total deferred income tax assets	57	75
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets	(39)	(48)
Accelerated depreciation rates	(833)	(844)
Regulatory assets and deferred debits, net		(4)
Total deferred income tax liabilities	(872)	(896)
Net deferred income tax liabilities	(815)	(821)
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	$ 29	$ 29