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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 |  |  |  |

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