Employee Benefit Plans (Components of Net Periodic Pension Costs) (Details) - Qualified Pension Plans - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 41	$ 44	$ 81	$ 88
Interest cost on projected benefit obligation	59	55	117	110
Expected return on plan assets	(141)	(140)	(281)	(279)
Amortization of actuarial loss	23	34	47	67
Amortization of prior service credit	(4)	(8)	(9)	(15)
Amortization of settlement charges	2	2	4	4
Net periodic pension costs	(20)	(13)	(41)	(25)
Duke Energy Carolinas
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	14	14	26	28
Interest cost on projected benefit obligation	13	12	27	25
Expected return on plan assets	(38)	(35)	(76)	(70)
Amortization of actuarial loss	5	8	10	15
Amortization of prior service credit	(1)	(2)	(2)	(4)
Amortization of settlement charges	2	2	3	3
Net periodic pension costs	(5)	(1)	(12)	(3)
Progress Energy
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	11	12	23	25
Interest cost on projected benefit obligation	18	18	36	35
Expected return on plan assets	(47)	(47)	(93)	(94)
Amortization of actuarial loss	7	9	13	19
Amortization of prior service credit				(1)
Amortization of settlement charges			1	1
Net periodic pension costs	(11)	(8)	(20)	(15)
Duke Energy Progress
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	7	8	14	15
Interest cost on projected benefit obligation	8	8	16	15
Expected return on plan assets	(22)	(21)	(44)	(42)
Amortization of actuarial loss	4	4	7	9
Amortization of prior service credit		(1)		(1)
Amortization of settlement charges	1	1	1	1
Net periodic pension costs	(2)	(1)	(6)	(3)
Duke Energy Florida
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	6	6	10	11
Interest cost on projected benefit obligation	10	9	20	19
Expected return on plan assets	(24)	(25)	(48)	(51)
Amortization of actuarial loss	3	5	6	10
Net periodic pension costs	(5)	(5)	(12)	(11)
Duke Energy Ohio
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	1	1	2	2
Interest cost on projected benefit obligation	3	4	6	7
Expected return on plan assets	(6)	(7)	(11)	(14)
Amortization of actuarial loss	1	1	2	3
Net periodic pension costs	(1)	(1)	(1)	(2)
Duke Energy Indiana
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	2	3	4	5
Interest cost on projected benefit obligation	5	4	10	9
Expected return on plan assets	(10)	(10)	(19)	(20)
Amortization of actuarial loss	3	4	5	7
Amortization of prior service credit	(1)	(1)	(1)	(1)
Net periodic pension costs	(1)		(1)
Piedmont
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	2	2	3	3
Interest cost on projected benefit obligation	2	2	4	4
Expected return on plan assets	(6)	(5)	(12)	(10)
Amortization of actuarial loss	1	3	3	5
Amortization of prior service credit	(2)	(4)	(4)	(5)
Net periodic pension costs	$ (3)	$ (2)	$ (6)	$ (3)