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Employee Benefit Plans (Amounts Recognized in Consolidated Balance Sheets) (Details) - USD ($) $ in Millions | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Noncurrent pension liability | $ 934 | $ 988
Regulatory assets | 15,018 | 15,622
Regulatory liabilities | 16,048 | 15,432
Duke Energy Carolinas |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Noncurrent pension liability | 84 | 99
Regulatory assets | 3,910 | 3,977
Regulatory liabilities | 6,678 | 6,198
Progress Energy |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Noncurrent pension liability | 488 | 521
Regulatory assets | 7,292 | 7,701
Regulatory liabilities | 5,555 | 5,329
Duke Energy Progress |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Noncurrent pension liability | 238 | 237
Regulatory assets | 4,678 | 4,814
Regulatory liabilities | 4,468 | 4,133
Duke Energy Florida |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Noncurrent pension liability | 218 | 254
Regulatory assets | 2,613 | 2,888
Regulatory liabilities | 1,087 | 1,196
Duke Energy Ohio |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Noncurrent pension liability | 100 | 79
Regulatory assets | 598 | 564
Regulatory liabilities | 827 | 897
Duke Energy Indiana |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Noncurrent pension liability | 148 | 115
Regulatory assets | 1,172 | 1,157
Regulatory liabilities | 1,740 | 1,747
Piedmont |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Noncurrent pension liability | 3 | 4
Regulatory assets | 363 | 357
Regulatory liabilities | 1,212 | 1,218
Pension Plan | Qualified Plan |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 621 | 433
Noncurrent pension liability | 32 | 69
Net amount recognized | 589 | 364
Regulatory assets | 1,972 | 2,184
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax asset | (23) | (43)
Prior year service cost (credit) arising during the year | (3) | (4)
Net actuarial loss (gain) | 111 | 126
Net amount recognized in accumulated other comprehensive income (loss) | 85 | 79
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss | 135 | 97
Unrecognized prior service (credit) cost | (32) | (32)
Pension Plan | Duke Energy Carolinas | Qualified Plan |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 340 | 214
Noncurrent pension liability | 0 | 0
Net amount recognized | 340 | 214
Regulatory assets | 420 | 576
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 | 22
Unrecognized prior service (credit) cost | (8) | (8)
Pension Plan | Progress Energy | Qualified Plan |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 322 | 242
Noncurrent pension liability | 32 | 69
Net amount recognized | 290 | 173
Regulatory assets | 717 | 796
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax asset | (1) | (2)
Prior year service cost (credit) arising during the year | 0 | 0
Net actuarial loss (gain) | 3 | 5
Net amount recognized in accumulated other comprehensive income (loss) | 2 | 3
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss | 43 | 37
Unrecognized prior service (credit) cost | (3) | (3)
Pension Plan | Duke Energy Progress | Qualified Plan |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 194 | 143
Noncurrent pension liability | 0 | 0
Net amount recognized | 194 | 143
Regulatory assets | 313 | 372
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 | 13
Unrecognized prior service (credit) cost | (2) | (2)
Pension Plan | Duke Energy Florida | Qualified Plan |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 123 | 96
Noncurrent pension liability | 32 | 69
Net amount recognized | 91 | 27
Regulatory assets | 404 | 424
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax asset | (1) | 0
Prior year service cost (credit) arising during the year | 0 | 0
Net actuarial loss (gain) | 3 | 0
Net amount recognized in accumulated other comprehensive income (loss) | 2 | 0
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss | 24 | 24
Unrecognized prior service (credit) cost | (1) | (1)
Pension Plan | Duke Energy Ohio | Qualified Plan |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 38 | 24
Noncurrent pension liability | 76 | 54
Net amount recognized | (38) | (30)
Regulatory assets | 112 | 100
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 | 3
Unrecognized prior service (credit) cost | (1) | 0
Pension Plan | Duke Energy Indiana | Qualified Plan |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 57 | 39
Noncurrent pension liability | 83 | 46
Net amount recognized | (26) | (7)
Regulatory assets | 204 | 182
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 | 5
Unrecognized prior service (credit) cost | (2) | (2)
Pension Plan | Piedmont | Qualified Plan |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Prefunded pension | 43 | 41
Noncurrent pension liability | 0 | 0
Net amount recognized | 43 | 41
Regulatory assets | 81 | 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 | 7
Unrecognized prior service (credit) cost | (9) | (9)
Other Post-Retirement Benefit Plans |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Current pension liability | 9 | 8
Noncurrent pension liability | 494 | 525
Total accrued pension liability | 503 | 533
Regulatory assets | 135 | 262
Regulatory liabilities | 149 | 301
Accumulated Other Comprehensive Income (Loss) [Abstract] |  |
Deferred income tax liability | 3 | 3
Prior year service cost (credit) arising during the year | (2) | (2)
Net actuarial loss (gain) | (13) | (9)
Net amount recognized in accumulated other comprehensive income (loss) | (12) | (8)
Amounts to be recognized in net periodic pension expense in the next year [Abstract] |  |
Unrecognized net actuarial loss | 5 | 4
Unrecognized prior service (credit) cost | (14) | (19)
Other Post-Retirement Benefit Plans | Duke Energy Carolinas |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Current pension liability | 0 | 0
Noncurrent pension liability | 45 | 59
Total accrued pension liability | 45 | 59
Regulatory assets | 0 | 0
Regulatory liabilities | 39 | 38
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 | 2
Unrecognized prior service (credit) cost | (4) | (5)
Other Post-Retirement Benefit Plans | Progress Energy |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Current pension liability | 5 | 5
Noncurrent pension liability | 299 | 298
Total accrued pension liability | 304 | 303
Regulatory assets | 135 | 262
Regulatory liabilities | 0 | 149
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 | 1
Unrecognized prior service (credit) cost | (3) | (7)
Other Post-Retirement Benefit Plans | Duke Energy Progress |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Current pension liability | 3 | 3
Noncurrent pension liability | 166 | 163
Total accrued pension liability | 169 | 166
Regulatory assets | 82 | 164
Regulatory liabilities | 0 | 93
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 | 0
Unrecognized prior service (credit) cost | (1) | (1)
Other Post-Retirement Benefit Plans | Duke Energy Florida |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Current pension liability | 2 | 2
Noncurrent pension liability | 133 | 135
Total accrued pension liability | 135 | 137
Regulatory assets | 53 | 98
Regulatory liabilities | 0 | 56
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 | 0
Unrecognized prior service (credit) cost | (2) | (6)
Other Post-Retirement Benefit Plans | Duke Energy Ohio |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Current pension liability | 1 | 2
Noncurrent pension liability | 19 | 19
Total accrued pension liability | 20 | 21
Regulatory assets | 0 | 0
Regulatory liabilities | 17 | 18
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 | 0
Unrecognized prior service (credit) cost | (1) | (1)
Other Post-Retirement Benefit Plans | Duke Energy Indiana |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Current pension liability | 0 | 0
Noncurrent pension liability | 59 | 62
Total accrued pension liability | 59 | 62
Regulatory assets | 36 | 41
Regulatory liabilities | 63 | 67
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 | 0
Unrecognized prior service (credit) cost | (1) | (1)
Other Post-Retirement Benefit Plans | Piedmont |  |
Amounts Recognized in Consolidated Balance Sheets [Abstract] |  |
Current pension liability | 0 | 0
Noncurrent pension liability | (4) | 1
Total accrued pension liability | (4) | 1
Regulatory assets | 0 | 0
Regulatory liabilities | 3 | 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 | 0
Unrecognized prior service (credit) cost | $ (2) | $ (2)

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- Definition The amount for the individual regulatory liability as itemized in a table of regulatory liabilities as of the end of the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 405 -Section 25 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6500807&loc=d3e48068-110394 + Details
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