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Investments in Debt and Equity Securities (Estimated Fair Value of Investments in Debt and Equity Securities) (Details) - USD ($) $ in Millions | Mar. 31, 2023 | Dec. 31, 2022
--- | --- | ---
Debt Securities, Available-for-sale |  |
Estimated Fair Value | $ 2,873 |
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 4,086 | $ 3,682
Unrealized Holding Losses | 277 | 395
Estimated Fair Value | 9,672 | 9,051
Duke Energy Carolinas |  |
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 1,329 |
Progress Energy |  |
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 1,291 |
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 1,679 | 1,512
Unrealized Holding Losses | 118 | 167
Estimated Fair Value | 4,081 | 3,890
Duke Energy Progress |  |
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 977 |
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 1,592 | 1,432
Unrealized Holding Losses | 98 | 142
Estimated Fair Value | 3,646 | 3,439
Duke Energy Florida |  |
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 314 |
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 87 | 80
Unrealized Holding Losses | 20 | 25
Estimated Fair Value | 434 | 450
Duke Energy Indiana |  |
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 64 |
NDTF |  |
Available-for-sale Securities |  |
Cash and cash equivalents | 161 | 215
Equity Securities, FV-NI |  |
Equity Securities, FV-NI, Accumulated Unrealized Gain | 4,048 | 3,658
Equity Securities, FV-NI, Accumulated Unrealized Loss | 60 | 105
Equity securities, FV-NI | 6,367 | 5,871
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 2,595 | 2,550
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 4,061 | 3,661
Unrealized Holding Losses | 252 | 359
Estimated Fair Value | 9,123 | 8,636
NDTF | Duke Energy Carolinas |  |
Available-for-sale Securities |  |
Cash and cash equivalents | 69 | 117
Equity Securities, FV-NI |  |
Equity Securities, FV-NI, Accumulated Unrealized Gain | 2,375 | 2,147
Equity Securities, FV-NI, Accumulated Unrealized Loss | 29 | 51
Equity securities, FV-NI | 3,677 | 3,367
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 1,329 | 1,298
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 2,382 | 2,149
Unrealized Holding Losses | 134 | 192
Estimated Fair Value | 5,075 | 4,782
NDTF | Progress Energy |  |
Available-for-sale Securities |  |
Cash and cash equivalents | 92 | 98
Equity Securities, FV-NI |  |
Equity Securities, FV-NI, Accumulated Unrealized Gain | 1,673 | 1,511
Equity Securities, FV-NI, Accumulated Unrealized Loss | 31 | 54
Equity securities, FV-NI | 2,690 | 2,504
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 1,266 | 1,252
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 1,679 | 1,512
Unrealized Holding Losses | 118 | 167
Estimated Fair Value | 4,048 | 3,854
NDTF | Duke Energy Progress |  |
Available-for-sale Securities |  |
Cash and cash equivalents | 72 | 56
Equity Securities, FV-NI |  |
Equity Securities, FV-NI, Accumulated Unrealized Gain | 1,586 | 1,431
Equity Securities, FV-NI, Accumulated Unrealized Loss | 31 | 54
Equity securities, FV-NI | 2,590 | 2,411
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 977 | 963
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 1,592 | 1,432
Unrealized Holding Losses | 98 | 142
Estimated Fair Value | 3,639 | 3,430
NDTF | Duke Energy Florida |  |
Available-for-sale Securities |  |
Cash and cash equivalents | 20 | 42
Equity Securities, FV-NI |  |
Equity Securities, FV-NI, Accumulated Unrealized Gain | 87 | 80
Equity securities, FV-NI | 100 | 93
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 289 | 289
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 87 | 80
Unrealized Holding Losses | 20 | 25
Estimated Fair Value | 409 | 424
Other Investments |  |
Available-for-sale Securities |  |
Cash and cash equivalents | 134 | 22
Equity Securities, FV-NI |  |
Equity Securities, FV-NI, Accumulated Unrealized Gain | 25 | 21
Equity Securities, FV-NI, Accumulated Unrealized Loss | 11 | 16
Equity securities, FV-NI | 137 | 128
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 278 | 265
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 25 | 21
Unrealized Holding Losses | 25 | 36
Estimated Fair Value | 549 | 415
Other Investments | Progress Energy |  |
Available-for-sale Securities |  |
Cash and cash equivalents | 8 | 11
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 25 | 25
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Estimated Fair Value | 33 | 36
Other Investments | Duke Energy Progress |  |
Available-for-sale Securities |  |
Cash and cash equivalents | 7 | 9
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Estimated Fair Value | 7 | 9
Other Investments | Duke Energy Florida |  |
Available-for-sale Securities |  |
Cash and cash equivalents |  | 1
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 25 | 25
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Estimated Fair Value | 25 | 26
Other Investments | Duke Energy Indiana |  |
Available-for-sale Securities |  |
Cash and cash equivalents | 1 | 1
Equity Securities, FV-NI |  |
Equity Securities, FV-NI, Accumulated Unrealized Gain | 3 | 2
Equity Securities, FV-NI, Accumulated Unrealized Loss | 11 | 16
Equity securities, FV-NI | 85 | 79
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 64 | 60
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 3 | 2
Unrealized Holding Losses | 13 | 20
Estimated Fair Value | 150 | 140
Corporate debt securities | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 3 | 1
Gross Unrealized Holding Losses | 65 | 85
Estimated Fair Value | 616 | 641
Corporate debt securities | NDTF | Duke Energy Carolinas |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 2 | 1
Gross Unrealized Holding Losses | 47 | 62
Estimated Fair Value | 384 | 401
Corporate debt securities | NDTF | Progress Energy |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 1 |
Gross Unrealized Holding Losses | 18 | 23
Estimated Fair Value | 232 | 240
Corporate debt securities | NDTF | Duke Energy Progress |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 1 |
Gross Unrealized Holding Losses | 17 | 22
Estimated Fair Value | 222 | 230
Corporate debt securities | NDTF | Duke Energy Florida |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Losses | 1 | 1
Estimated Fair Value | 10 | 10
Corporate debt securities | Other Investments |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Losses | 10 | 12
Estimated Fair Value | 87 | 84
Corporate debt securities | Other Investments | Duke Energy Indiana |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Losses |  | 1
Estimated Fair Value | 9 | 8
Municipal bonds | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 1 |
Gross Unrealized Holding Losses | 27 | 39
Estimated Fair Value | 337 | 330
Municipal bonds | NDTF | Duke Energy Carolinas |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Losses | 5 | 10
Estimated Fair Value | 56 | 64
Municipal bonds | NDTF | Progress Energy |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 1 |
Gross Unrealized Holding Losses | 22 | 29
Estimated Fair Value | 281 | 266
Municipal bonds | NDTF | Duke Energy Progress |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 1 |
Gross Unrealized Holding Losses | 22 | 29
Estimated Fair Value | 281 | 266
Municipal bonds | Other Investments |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Losses | 2 | 3
Estimated Fair Value | 80 | 78
Municipal bonds | Other Investments | Progress Energy |  |
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 25 | 25
Municipal bonds | Other Investments | Duke Energy Florida |  |
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 25 | 25
Municipal bonds | Other Investments | Duke Energy Indiana |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Losses | 2 | 3
Estimated Fair Value | 46 | 45
U.S. government bonds | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 9 | 2
Gross Unrealized Holding Losses | 85 | 112
Estimated Fair Value | 1,495 | 1,423
U.S. government bonds | NDTF | Duke Energy Carolinas |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 5 | 1
Gross Unrealized Holding Losses | 38 | 51
Estimated Fair Value | 746 | 685
U.S. government bonds | NDTF | Progress Energy |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 4 | 1
Gross Unrealized Holding Losses | 47 | 61
Estimated Fair Value | 749 | 738
U.S. government bonds | NDTF | Duke Energy Progress |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 4 | 1
Gross Unrealized Holding Losses | 28 | 37
Estimated Fair Value | 470 | 460
U.S. government bonds | NDTF | Duke Energy Florida |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Losses | 19 | 24
Estimated Fair Value | 279 | 278
U.S. government bonds | Other Investments |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Losses |  | 2
Estimated Fair Value | 69 | 62
U.S. government bonds | Other Investments | Duke Energy Indiana |  |
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 9 | 7
Other debt securities | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Losses | 15 | 18
Estimated Fair Value | 147 | 156
Other debt securities | NDTF | Duke Energy Carolinas |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Losses | 15 | 18
Estimated Fair Value | 143 | 148
Other debt securities | NDTF | Progress Energy |  |
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 4 | 8
Other debt securities | NDTF | Duke Energy Progress |  |
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 4 | 7
Other debt securities | NDTF | Duke Energy Florida |  |
Debt Securities, Available-for-sale |  |
Estimated Fair Value |  | 1
Other debt securities | Other Investments |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Losses | 2 | 3
Estimated Fair Value | $ 42 | $ 41

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