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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, 2024 | Dec. 31, 2023
--- | --- | ---
Debt Securities, Available-for-sale |  |
Estimated Fair Value | $ 3,081 |
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 5,621 | $ 5,019
Unrealized Holding Losses | 191 | 171
Estimated Fair Value | 11,252 | 10,603
NDTF |  |
Cash and Cash Equivalents |  |
Estimated Fair Value | 140 | 133
Equity Securities, FV-NI |  |
Gross Unrealized Holding Gains | 5,553 | 4,942
Gross Unrealized Holding Losses | 27 | 22
Estimated Fair Value | 7,837 | 7,278
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 2,810 | 2,732
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 5,574 | 4,985
Unrealized Holding Losses | 178 | 159
Estimated Fair Value | 10,787 | 10,143
Other Investments |  |
Cash and Cash Equivalents |  |
Estimated Fair Value | 21 | 31
Equity Securities, FV-NI |  |
Gross Unrealized Holding Gains | 47 | 33
Gross Unrealized Holding Losses | 0 | 0
Estimated Fair Value | 173 | 158
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 271 | 271
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 47 | 34
Unrealized Holding Losses | 13 | 12
Estimated Fair Value | 465 | 460
Duke Energy Carolinas |  |
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 1,480 |
Duke Energy Carolinas | NDTF |  |
Cash and Cash Equivalents |  |
Estimated Fair Value | 81 | 51
Equity Securities, FV-NI |  |
Gross Unrealized Holding Gains | 3,226 | 2,886
Gross Unrealized Holding Losses | 19 | 14
Estimated Fair Value | 4,514 | 4,196
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 1,480 | 1,438
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 3,232 | 2,904
Unrealized Holding Losses | 114 | 99
Estimated Fair Value | 6,075 | 5,685
Duke Energy Carolinas | Other Investments |  |
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 0 |
Progress Energy |  |
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 1,354 |
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 2,342 | 2,081
Unrealized Holding Losses | 64 | 61
Estimated Fair Value | 4,751 | 4,499
Progress Energy | NDTF |  |
Cash and Cash Equivalents |  |
Estimated Fair Value | 59 | 82
Equity Securities, FV-NI |  |
Gross Unrealized Holding Gains | 2,327 | 2,056
Gross Unrealized Holding Losses | 8 | 8
Estimated Fair Value | 3,323 | 3,082
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 1,330 | 1,294
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 2,342 | 2,081
Unrealized Holding Losses | 64 | 60
Estimated Fair Value | 4,712 | 4,458
Progress Energy | Other Investments |  |
Cash and Cash Equivalents |  |
Estimated Fair Value | 15 | 18
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 24 | 23
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 0 | 0
Unrealized Holding Losses | 0 | 1
Estimated Fair Value | 39 | 41
Duke Energy Progress |  |
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 1,097 |
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 2,230 | 1,979
Unrealized Holding Losses | 51 | 46
Estimated Fair Value | 4,357 | 4,089
Duke Energy Progress | NDTF |  |
Cash and Cash Equivalents |  |
Estimated Fair Value | 48 | 55
Equity Securities, FV-NI |  |
Gross Unrealized Holding Gains | 2,216 | 1,956
Gross Unrealized Holding Losses | 8 | 8
Estimated Fair Value | 3,200 | 2,970
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 1,097 | 1,050
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 2,230 | 1,979
Unrealized Holding Losses | 51 | 46
Estimated Fair Value | 4,345 | 4,075
Duke Energy Progress | Other Investments |  |
Cash and Cash Equivalents |  |
Estimated Fair Value | 12 | 14
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 0 | 0
Unrealized Holding Losses | 0 | 0
Estimated Fair Value | 12 | 14
Duke Energy Florida |  |
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 257 |
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 112 | 102
Unrealized Holding Losses | 13 | 15
Estimated Fair Value | 393 | 409
Duke Energy Florida | NDTF |  |
Cash and Cash Equivalents |  |
Estimated Fair Value | 11 | 27
Equity Securities, FV-NI |  |
Gross Unrealized Holding Gains | 111 | 100
Gross Unrealized Holding Losses | 0 | 0
Estimated Fair Value | 123 | 112
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 233 | 244
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 112 | 102
Unrealized Holding Losses | 13 | 14
Estimated Fair Value | 367 | 383
Duke Energy Florida | Other Investments |  |
Cash and Cash Equivalents |  |
Estimated Fair Value | 2 | 3
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 24 | 23
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 0 | 0
Unrealized Holding Losses | 0 | 1
Estimated Fair Value | 26 | 26
Duke Energy Indiana |  |
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 63 |
Duke Energy Indiana | Other Investments |  |
Cash and Cash Equivalents |  |
Estimated Fair Value | 1 | 1
Equity Securities, FV-NI |  |
Gross Unrealized Holding Gains | 13 | 4
Gross Unrealized Holding Losses | 0 | 0
Estimated Fair Value | 108 | 98
Debt Securities, Available-for-sale |  |
Estimated Fair Value | 63 | 64
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract] |  |
Unrealized Holding Gains | 13 | 5
Unrealized Holding Losses | 1 | 1
Estimated Fair Value | 172 | 163
Corporate debt securities | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 8 | 12
Gross Unrealized Holding Losses | 46 | 43
Estimated Fair Value | 659 | 632
Corporate debt securities | Other Investments |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 0 | 0
Gross Unrealized Holding Losses | 6 | 6
Estimated Fair Value | 87 | 82
Corporate debt securities | Duke Energy Carolinas | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 2 | 4
Gross Unrealized Holding Losses | 37 | 35
Estimated Fair Value | 397 | 390
Corporate debt securities | Progress Energy | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 6 | 8
Gross Unrealized Holding Losses | 9 | 8
Estimated Fair Value | 262 | 242
Corporate debt securities | Duke Energy Progress | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 5 | 7
Gross Unrealized Holding Losses | 9 | 8
Estimated Fair Value | 248 | 229
Corporate debt securities | Duke Energy Florida | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 1 | 1
Gross Unrealized Holding Losses | 0 | 0
Estimated Fair Value | 14 | 13
Corporate debt securities | Duke Energy Indiana | Other Investments |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 0 | 0
Gross Unrealized Holding Losses | 0 | 0
Estimated Fair Value | 8 | 8
Municipal bonds | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 4 | 6
Gross Unrealized Holding Losses | 16 | 16
Estimated Fair Value | 332 | 347
Municipal bonds | Other Investments |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 0 | 1
Gross Unrealized Holding Losses | 1 | 2
Estimated Fair Value | 79 | 77
Municipal bonds | Duke Energy Carolinas | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 0 | 0
Gross Unrealized Holding Losses | 4 | 4
Estimated Fair Value | 38 | 50
Municipal bonds | Progress Energy | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 4 | 6
Gross Unrealized Holding Losses | 12 | 12
Estimated Fair Value | 294 | 297
Municipal bonds | Progress Energy | Other Investments |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 0 | 0
Gross Unrealized Holding Losses | 0 | 1
Estimated Fair Value | 24 | 23
Municipal bonds | Duke Energy Progress | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 4 | 6
Gross Unrealized Holding Losses | 12 | 12
Estimated Fair Value | 294 | 297
Municipal bonds | Duke Energy Florida | Other Investments |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 0 | 0
Gross Unrealized Holding Losses | 0 | 1
Estimated Fair Value | 24 | 23
Municipal bonds | Duke Energy Indiana | Other Investments |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 0 | 1
Gross Unrealized Holding Losses | 1 | 1
Estimated Fair Value | 45 | 46
U.S. government bonds | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 9 | 24
Gross Unrealized Holding Losses | 76 | 65
Estimated Fair Value | 1,610 | 1,575
U.S. government bonds | Other Investments |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 0 | 0
Gross Unrealized Holding Losses | 3 | 2
Estimated Fair Value | 60 | 65
U.S. government bonds | Duke Energy Carolinas | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 4 | 13
Gross Unrealized Holding Losses | 41 | 33
Estimated Fair Value | 854 | 826
U.S. government bonds | Progress Energy | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 5 | 11
Gross Unrealized Holding Losses | 35 | 32
Estimated Fair Value | 756 | 749
U.S. government bonds | Duke Energy Progress | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 5 | 10
Gross Unrealized Holding Losses | 22 | 18
Estimated Fair Value | 539 | 518
U.S. government bonds | Duke Energy Florida | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 0 | 1
Gross Unrealized Holding Losses | 13 | 14
Estimated Fair Value | 217 | 231
U.S. government bonds | Duke Energy Indiana | Other Investments |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 0 | 0
Gross Unrealized Holding Losses | 0 | 0
Estimated Fair Value | 10 | 10
Other debt securities | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 0 | 1
Gross Unrealized Holding Losses | 13 | 13
Estimated Fair Value | 209 | 178
Other debt securities | Other Investments |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 0 | 0
Gross Unrealized Holding Losses | 3 | 2
Estimated Fair Value | 45 | 47
Other debt securities | Duke Energy Carolinas | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 0 | 1
Gross Unrealized Holding Losses | 13 | 13
Estimated Fair Value | 191 | 172
Other debt securities | Progress Energy | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 0 | 0
Gross Unrealized Holding Losses | 0 | 0
Estimated Fair Value | 18 | 6
Other debt securities | Duke Energy Progress | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 0 | 0
Gross Unrealized Holding Losses | 0 | 0
Estimated Fair Value | 16 | 6
Other debt securities | Duke Energy Florida | NDTF |  |
Debt Securities, Available-for-sale |  |
Gross Unrealized Holding Gains | 0 | 0
Gross Unrealized Holding Losses | 0 | 0
Estimated Fair Value | $ 2 | $ 0

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