Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2022
Defined Benefit Plan Disclosure [Line Items]
Maximum years of participation	35 years
Vesting period	3 years
Master Trust
Defined Benefit Plan Disclosure [Line Items]
Expected long-term rate of return on plan assets	6.50%
Target allocation	100.00%
Fair value of securities on loan	$ 542	$ 482
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions			$ 77
Pension Plan | Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years	14 years
Projected benefit obligation	$ 8,207	8,634	$ 8,321
Accumulated Benefit Obligation at measurement date	8,144	8,577
Benefits paid	$ 615	$ 541
Expected long-term rate of return on plan assets	6.50%	6.85%	6.85%
Pension Plan | Nonqualified Plan
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 300
Accumulated Benefit Obligation at measurement date	300
Employer contributions	24
Benefits paid	$ 24
Pension Plan | Master Trust
Defined Benefit Plan Disclosure [Line Items]
Master trust allocation percentage	98.00%
Other Post-Retirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years	4 years
Projected benefit obligation	$ 625	$ 709	$ 723
Employer contributions	18
Benefits paid	$ 73	$ 75
Expected long-term rate of return on plan assets	6.50%	6.85%	6.85%
Other Post-Retirement Benefit Plans | Master Trust
Defined Benefit Plan Disclosure [Line Items]
Master trust allocation percentage	2.00%
Duke Energy Progress | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions			$ 4
Duke Energy Progress | Pension Plan | Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years	14 years
Projected benefit obligation	$ 1,153	$ 1,193	1,170
Accumulated Benefit Obligation at measurement date	1,154	1,194
Benefits paid	80	83
Duke Energy Progress | Pension Plan | Nonqualified Plan
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	31
Accumulated Benefit Obligation at measurement date	31
Employer contributions	3
Benefits paid	$ 3
Duke Energy Progress | Other Post-Retirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years	6 years
Projected benefit obligation	$ 147	166	168
Employer contributions	13
Benefits paid	$ 16	15
Duke Energy Ohio | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions			2
Duke Energy Ohio | Pension Plan | Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years	14 years
Projected benefit obligation	$ 450	502	481
Accumulated Benefit Obligation at measurement date	439	493
Benefits paid	50	34
Duke Energy Ohio | Pension Plan | Nonqualified Plan
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	3
Accumulated Benefit Obligation at measurement date	$ 3
Duke Energy Ohio | Other Post-Retirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years	5 years
Projected benefit obligation	$ 25	27	29
Employer contributions	1
Benefits paid	$ 3	4
Progress Energy | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions			57
Progress Energy | Pension Plan | Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years	15 years
Projected benefit obligation	$ 2,560	2,715	2,608
Accumulated Benefit Obligation at measurement date	2,529	2,684
Benefits paid	161	160
Progress Energy | Pension Plan | Nonqualified Plan
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	104
Accumulated Benefit Obligation at measurement date	104
Employer contributions	8
Benefits paid	$ 8
Progress Energy | Other Post-Retirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years	6 years
Projected benefit obligation	$ 263	299	303
Employer contributions	24
Benefits paid	$ 29	28
Duke Energy Florida | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions			53
Duke Energy Florida | Pension Plan | Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years	15 years
Projected benefit obligation	$ 1,392	1,507	1,424
Accumulated Benefit Obligation at measurement date	1,361	1,476
Benefits paid	81	76
Duke Energy Florida | Pension Plan | Nonqualified Plan
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	41
Accumulated Benefit Obligation at measurement date	41
Employer contributions	3
Benefits paid	$ 3
Duke Energy Florida | Other Post-Retirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years	7 years
Projected benefit obligation	$ 112	130	135
Employer contributions	10
Benefits paid	$ 13	13
Duke Energy Carolinas | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions			7
Duke Energy Carolinas | Pension Plan | Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years	13 years
Projected benefit obligation	$ 1,903	1,988	1,923
Accumulated Benefit Obligation at measurement date	1,904	1,989
Benefits paid	148	137
Duke Energy Carolinas | Pension Plan | Nonqualified Plan
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	12
Accumulated Benefit Obligation at measurement date	12
Employer contributions	1
Benefits paid	$ 1
Duke Energy Carolinas | Other Post-Retirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years	6 years
Projected benefit obligation	$ 149	174	175
Employer contributions	3
Benefits paid	$ 19	18
Duke Energy Indiana | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions			2
Duke Energy Indiana | Pension Plan | Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years	13 years
Projected benefit obligation	$ 680	715	693
Accumulated Benefit Obligation at measurement date	672	709
Benefits paid	52	49
Duke Energy Indiana | Pension Plan | Nonqualified Plan
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	2
Accumulated Benefit Obligation at measurement date	$ 2
Duke Energy Indiana | Other Post-Retirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years	6 years
Projected benefit obligation	$ 54	61	64
Employer contributions	6
Benefits paid	$ 9	9
Piedmont
Defined Benefit Plan Disclosure [Line Items]
Term	3 years
Piedmont | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions			1
Piedmont | Pension Plan | Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years	9 years
Projected benefit obligation	$ 273	293	292
Accumulated Benefit Obligation at measurement date	274	294
Benefits paid	28	27
Piedmont | Pension Plan | Nonqualified Plan
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	3
Accumulated Benefit Obligation at measurement date	$ 3
Piedmont | Other Post-Retirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years	6 years
Projected benefit obligation	$ 27	30	$ 30
Employer contributions	1
Benefits paid	$ 2	$ 2
Liability Hedging Assets | Pension Plan | Master Trust | Subsequent Event
Defined Benefit Plan Disclosure [Line Items]
Target allocation				60.00%
Return Seeking Assets | Pension Plan | Master Trust | Subsequent Event
Defined Benefit Plan Disclosure [Line Items]
Target allocation				40.00%
Minimum | Pension Plan | Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Expected long-term rate of return on plan assets