Employee Benefit Plans (Components of Net Periodic Pension Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension Plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Amortization of regulatory asset	$ 3	$ 4	$ 4
Pension Plan | Qualified Plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	176	165
Service cost	168	157	158
Interest cost	220	269	317
Expected return on plan assets	(558)	(572)	(567)
Amortization of prior service credit	133	128	108
Amortization of prior service cost (credit)	(29)	(32)	(32)
Amortization of settlement charge			6
Amortization of settlement charges	9	18
Net periodic costs	(49)	(24)	(10)
Pension Plan | Duke Energy Carolinas | Qualified Plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	56	51
Service cost	54	49	49
Interest cost	51	62	75
Expected return on plan assets	(141)	(145)	(147)
Amortization of prior service credit	29	28	24
Amortization of prior service cost (credit)	(8)	(8)	(8)
Amortization of settlement charge			2
Amortization of settlement charges	5	9
Net periodic costs	(8)	(3)	(5)
Pension Plan | Progress Energy | Qualified Plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	50	48
Service cost	48	46	46
Interest cost	70	85	100
Expected return on plan assets	(187)	(190)	(178)
Amortization of prior service credit	38	41	39
Amortization of prior service cost (credit)	(2)	(3)	(3)
Amortization of settlement charge			1
Amortization of settlement charges	2	7
Net periodic costs	(29)	(12)	5
Pension Plan | Duke Energy Progress | Qualified Plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	29	27
Service cost	28	26	26
Interest cost	30	38	45
Expected return on plan assets	(84)	(87)	(88)
Amortization of prior service credit	18	18	15
Amortization of prior service cost (credit)	(1)	(2)	(2)
Amortization of settlement charge			1
Amortization of settlement charges	2	6
Net periodic costs	(6)		(3)
Pension Plan | Duke Energy Florida | Qualified Plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	21	21
Service cost	20	20	20
Interest cost	39	46	54
Expected return on plan assets	(102)	(101)	(89)
Amortization of prior service credit	20	23	24
Amortization of prior service cost (credit)	(1)	(1)	(1)
Amortization of settlement charges	1	1
Net periodic costs	(22)	(11)	8
Pension Plan | Duke Energy Ohio
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Amortization of regulatory asset	1	2	2
Pension Plan | Duke Energy Ohio | Qualified Plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	5	5
Service cost	5	4	4
Interest cost	13	15	18
Expected return on plan assets	(28)	(28)	(28)
Amortization of prior service credit	7	6	4
Amortization of prior service cost (credit)	(1)
Amortization of settlement charge			2
Net periodic costs	(4)	(2)
Pension Plan | Duke Energy Indiana | Qualified Plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	10	9
Service cost	9	8	9
Interest cost	18	22	26
Expected return on plan assets	(40)	(42)	(43)
Amortization of prior service credit	13	12	8
Amortization of prior service cost (credit)	(2)	(2)	(2)
Amortization of settlement charges		1
Net periodic costs	(1)		(2)
Pension Plan | Piedmont | Qualified Plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	6	6
Service cost	6	5	5
Interest cost	7	9	10
Expected return on plan assets	(20)	(21)	(22)
Amortization of prior service credit	10	9	8
Amortization of prior service cost (credit)	(9)	(9)	(9)
Amortization of settlement charges	1	1
Net periodic costs	(5)	(5)	(8)
Other Post-Retirement Benefit Plans
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	4	4	4
Interest cost	18	23	30
Expected return on plan assets	(11)	(13)	(12)
Amortization of prior service credit	2	2	4
Amortization of prior service cost (credit)	(13)	(14)	(19)
Net periodic costs		2	7
Amortization of regulatory asset	5	6	6
Other Post-Retirement Benefit Plans | Duke Energy Carolinas
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	1	1	1
Interest cost	4	5	7
Expected return on plan assets	(7)	(8)	(7)
Amortization of prior service credit			2
Amortization of prior service cost (credit)	(4)	(4)	(5)
Net periodic costs	(6)	(6)	(2)
Other Post-Retirement Benefit Plans | Progress Energy
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	1	1	1
Interest cost	7	10	12
Amortization of prior service credit	1	1	1
Amortization of prior service cost (credit)	(2)	(3)	(8)
Net periodic costs	7	9	6
Other Post-Retirement Benefit Plans | Duke Energy Progress
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Interest cost	4	5	7
Amortization of prior service cost (credit)	(1)	(1)	(1)
Net periodic costs	3	4	6
Other Post-Retirement Benefit Plans | Duke Energy Florida
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost			1
Interest cost	3	4	5
Amortization of prior service credit	1	1	1
Amortization of prior service cost (credit)	(1)	(2)	(7)
Net periodic costs	3	3
Other Post-Retirement Benefit Plans | Duke Energy Ohio
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Interest cost	1	1	1
Amortization of prior service cost (credit)	(1)	(1)	(1)
Amortization of regulatory asset	1	1	2
Other Post-Retirement Benefit Plans | Duke Energy Indiana
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	1	1	1
Interest cost	1	2	3
Amortization of prior service credit	4	4	4
Amortization of prior service cost (credit)	(1)	(1)	(1)
Net periodic costs	5	6	7
Other Post-Retirement Benefit Plans | Piedmont
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Interest cost	1	1	1
Expected return on plan assets	(2)	(2)	(1)
Amortization of prior service cost (credit)	(2)	(2)	(2)
Net periodic costs	$ (3)	$ (3)	$ (2)