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Employee Benefit Plans (Amounts Recognized in Consolidated Balance Sheets) (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Noncurrent pension liability | $ 969 | $ 934
Regulatory assets | 14,062 | 15,018
Regulatory liabilities | 16,406 | 16,048
Duke Energy Carolinas |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Noncurrent pension liability | 73 | 84
Regulatory assets | 3,469 | 3,910
Regulatory liabilities | 7,008 | 6,678
Progress Energy |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Noncurrent pension liability | 505 | 488
Regulatory assets | 6,533 | 7,292
Regulatory liabilities | 5,691 | 5,555
Duke Energy Progress |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Noncurrent pension liability | 242 | 238
Regulatory assets | 4,468 | 4,678
Regulatory liabilities | 4,924 | 4,468
Duke Energy Florida |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Noncurrent pension liability | 231 | 218
Regulatory assets | 2,064 | 2,613
Regulatory liabilities | 768 | 1,087
Duke Energy Ohio |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Noncurrent pension liability | 113 | 100
Regulatory assets | 649 | 598
Regulatory liabilities | 813 | 827
Duke Energy Indiana |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Noncurrent pension liability | 171 | 148
Regulatory assets | 1,328 | 1,172
Regulatory liabilities | 1,738 | 1,740
Piedmont |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Noncurrent pension liability | 8 | 3
Regulatory assets | 455 | 363
Regulatory liabilities | 1,132 | 1,212
Pension Plan | Qualified Plan |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 780 | 621
Noncurrent pension liability | 77 | 32
Net amount recognized | 703 | 589
Regulatory assets | 1,910 | 1,972
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax asset | (21) | (23)
Prior year service cost (credit) arising during the year | (2) | (3)
Net actuarial loss (gain) | 100 | 111
Net amount recognized in accumulated other comprehensive income (loss) | 77 | 85
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss |  | 135
Unrecognized prior service (credit) cost |  | (32)
Pension Plan | Duke Energy Carolinas | Qualified Plan |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 393 | 340
Noncurrent pension liability | 0 | 0
Net amount recognized | 393 | 340
Regulatory assets | 381 | 420
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax asset | 0 | 0
Prior year service cost (credit) arising during the year | 0 | 0
Net actuarial loss (gain) | 0 | 0
Net amount recognized in accumulated other comprehensive income (loss) | 0 | 0
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss |  | 29
Unrecognized prior service (credit) cost |  | (8)
Pension Plan | Progress Energy | Qualified Plan |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 379 | 322
Noncurrent pension liability | 45 | 32
Net amount recognized | 334 | 290
Regulatory assets | 691 | 717
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax asset | 0 | (1)
Prior year service cost (credit) arising during the year | 0 | 0
Net actuarial loss (gain) | 2 | 3
Net amount recognized in accumulated other comprehensive income (loss) | 2 | 2
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss |  | 43
Unrecognized prior service (credit) cost |  | (3)
Pension Plan | Duke Energy Progress | Qualified Plan |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 229 | 194
Noncurrent pension liability | 0 | 0
Net amount recognized | 229 | 194
Regulatory assets | 283 | 313
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax asset | 0 | 0
Prior year service cost (credit) arising during the year | 0 | 0
Net actuarial loss (gain) | 0 | 0
Net amount recognized in accumulated other comprehensive income (loss) | 0 | 0
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss |  | 19
Unrecognized prior service (credit) cost |  | (2)
Pension Plan | Duke Energy Florida | Qualified Plan |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 143 | 123
Noncurrent pension liability | 45 | 32
Net amount recognized | 98 | 91
Regulatory assets | 408 | 404
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax asset | 0 | (1)
Prior year service cost (credit) arising during the year | 0 | 0
Net actuarial loss (gain) | 0 | 3
Net amount recognized in accumulated other comprehensive income (loss) | 0 | 2
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss |  | 24
Unrecognized prior service (credit) cost |  | (1)
Pension Plan | Duke Energy Ohio | Qualified Plan |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 58 | 38
Noncurrent pension liability | 88 | 76
Net amount recognized | (30) | (38)
Regulatory assets | 110 | 112
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax asset | 0 | 0
Prior year service cost (credit) arising during the year | 0 | 0
Net actuarial loss (gain) | 0 | 0
Net amount recognized in accumulated other comprehensive income (loss) | 0 | 0
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss |  | 7
Unrecognized prior service (credit) cost |  | (1)
Pension Plan | Duke Energy Indiana | Qualified Plan |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 79 | 57
Noncurrent pension liability | 110 | 83
Net amount recognized | (31) | (26)
Regulatory assets | 209 | 204
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax asset | 0 | 0
Prior year service cost (credit) arising during the year | 0 | 0
Net actuarial loss (gain) | 0 | 0
Net amount recognized in accumulated other comprehensive income (loss) | 0 | 0
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss |  | 10
Unrecognized prior service (credit) cost |  | (2)
Pension Plan | Piedmont | Qualified Plan |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 50 | 43
Noncurrent pension liability | 0 | 0
Net amount recognized | 50 | 43
Regulatory assets | 80 | 81
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax asset | 0 | 0
Prior year service cost (credit) arising during the year | 0 | 0
Net actuarial loss (gain) | 0 | 0
Net amount recognized in accumulated other comprehensive income (loss) | 0 | 0
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss |  | 9
Unrecognized prior service (credit) cost |  | (9)
Other Post-Retirement Benefit Plans |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 8 |
Current pension liability | 9 | 9
Noncurrent pension liability | 471 | 494
Net amount recognized | (472) |
Total accrued pension liability |  | 503
Regulatory assets | 144 | 135
Regulatory liabilities | 139 | 149
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax liability | 3 | 3
Prior year service cost (credit) arising during the year | (1) | (2)
Net actuarial loss (gain) | (13) | (13)
Net amount recognized in accumulated other comprehensive income (loss) | (11) | (12)
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss |  | 5
Unrecognized prior service (credit) cost |  | (14)
Other Post-Retirement Benefit Plans | Duke Energy Carolinas |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 0 |
Current pension liability | 0 | 0
Noncurrent pension liability | 35 | 45
Net amount recognized | (35) |
Total accrued pension liability |  | 45
Regulatory assets | 0 | 0
Regulatory liabilities | 32 | 39
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax liability | 0 | 0
Prior year service cost (credit) arising during the year | 0 | 0
Net actuarial loss (gain) | 0 | 0
Net amount recognized in accumulated other comprehensive income (loss) | 0 | 0
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss |  | 3
Unrecognized prior service (credit) cost |  | (4)
Other Post-Retirement Benefit Plans | Progress Energy |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 0 |
Current pension liability | 6 | 5
Noncurrent pension liability | 294 | 299
Net amount recognized | (300) |
Total accrued pension liability |  | 304
Regulatory assets | 144 | 135
Regulatory liabilities | 0 | 0
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax liability | 0 | 0
Prior year service cost (credit) arising during the year | 0 | 0
Net actuarial loss (gain) | 0 | 0
Net amount recognized in accumulated other comprehensive income (loss) | 0 | 0
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss |  | 1
Unrecognized prior service (credit) cost |  | (3)
Other Post-Retirement Benefit Plans | Duke Energy Progress |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 0 |
Current pension liability | 4 | 3
Noncurrent pension liability | 164 | 163
Net amount recognized | (168) |
Total accrued pension liability |  | 166
Regulatory assets | 88 | 82
Regulatory liabilities | 0 | 0
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax liability | 0 | 0
Prior year service cost (credit) arising during the year | 0 | 0
Net actuarial loss (gain) | 0 | 0
Net amount recognized in accumulated other comprehensive income (loss) | 0 | 0
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss |  | 0
Unrecognized prior service (credit) cost |  | (1)
Other Post-Retirement Benefit Plans | Duke Energy Florida |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 0 |
Current pension liability | 2 | 2
Noncurrent pension liability | 129 | 133
Net amount recognized | (131) |
Total accrued pension liability |  | 135
Regulatory assets | 56 | 53
Regulatory liabilities | 0 | 0
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax liability | 0 | 0
Prior year service cost (credit) arising during the year | 0 | 0
Net actuarial loss (gain) | 0 | 0
Net amount recognized in accumulated other comprehensive income (loss) | 0 | 0
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss |  | 1
Unrecognized prior service (credit) cost |  | (2)
Other Post-Retirement Benefit Plans | Duke Energy Ohio |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 1 |
Current pension liability | 2 | 1
Noncurrent pension liability | 17 | 19
Net amount recognized | (18) |
Total accrued pension liability |  | 20
Regulatory assets | 0 | 0
Regulatory liabilities | 17 | 17
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax liability | 0 | 0
Prior year service cost (credit) arising during the year | 0 | 0
Net actuarial loss (gain) | 0 | 0
Net amount recognized in accumulated other comprehensive income (loss) | 0 | 0
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss |  | 0
Unrecognized prior service (credit) cost |  | (1)
Other Post-Retirement Benefit Plans | Duke Energy Indiana |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 0 |
Current pension liability | 0 | 0
Noncurrent pension liability | 54 | 59
Net amount recognized | (54) |
Total accrued pension liability |  | 59
Regulatory assets | 32 | 36
Regulatory liabilities | 62 | 63
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax liability | 0 | 0
Prior year service cost (credit) arising during the year | 0 | 0
Net actuarial loss (gain) | 0 | 0
Net amount recognized in accumulated other comprehensive income (loss) | 0 | 0
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss |  | 0
Unrecognized prior service (credit) cost |  | (1)
Other Post-Retirement Benefit Plans | Piedmont |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 7 |
Current pension liability | 0 | 0
Noncurrent pension liability | 0 | (4)
Net amount recognized | 7 |
Total accrued pension liability |  | (4)
Regulatory assets | 0 | 0
Regulatory liabilities | 3 | 3
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax liability | 0 | 0
Prior year service cost (credit) arising during the year | 0 | 0
Net actuarial loss (gain) | 0 | 0
Net amount recognized in accumulated other comprehensive income (loss) | $ 0 | 0
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss |  | 0
Unrecognized prior service (credit) cost |  | $ (2)

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