Investments in Debt and Equity Securities (Estimated Fair Value of Investments in Debt and Equity Securities) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale
Estimated Fair Value	$ 3,003
Total Investments
Unrealized Holding Gains	5,019	$ 3,682
Unrealized Holding Losses	171	395
Estimated Fair Value	10,603	9,051
NDTF
Equity Securities, FV-NI
Gross Unrealized Holding Gains	4,942	3,658
Gross Unrealized Holding Losses	22	105
Estimated Fair Value	7,278	5,871
Debt Securities, Available-for-sale
Estimated Fair Value	2,732	2,550
Total Investments
Unrealized Holding Gains	4,985	3,661
Unrealized Holding Losses	159	359
Estimated Fair Value	10,143	8,636
NDTF | Cash and cash equivalents
Cash and Cash Equivalents
Estimated Fair Value	133	215
NDTF | Corporate debt securities
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	12	1
Gross Unrealized Holding Losses	43	85
Estimated Fair Value	632	641
NDTF | Municipal bonds
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	6
Gross Unrealized Holding Losses	16	39
Estimated Fair Value	347	330
NDTF | U.S. government bonds
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	24	2
Gross Unrealized Holding Losses	65	112
Estimated Fair Value	1,575	1,423
NDTF | Other debt securities
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	1
Gross Unrealized Holding Losses	13	18
Estimated Fair Value	178	156
Other Investments
Equity Securities, FV-NI
Gross Unrealized Holding Gains	33	21
Gross Unrealized Holding Losses		16
Estimated Fair Value	158	128
Debt Securities, Available-for-sale
Estimated Fair Value	271	265
Total Investments
Unrealized Holding Gains	34	21
Unrealized Holding Losses	12	36
Estimated Fair Value	460	415
Other Investments | Cash and cash equivalents
Cash and Cash Equivalents
Estimated Fair Value	31	22
Other Investments | Corporate debt securities
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	6	12
Estimated Fair Value	82	84
Other Investments | Municipal bonds
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	1
Gross Unrealized Holding Losses	2	3
Estimated Fair Value	77	78
Other Investments | U.S. government bonds
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	2	2
Estimated Fair Value	65	62
Other Investments | Other debt securities
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	2	3
Estimated Fair Value	47	41
Duke Energy Carolinas
Debt Securities, Available-for-sale
Estimated Fair Value	1,438
Duke Energy Carolinas | NDTF
Equity Securities, FV-NI
Gross Unrealized Holding Gains	2,886	2,147
Gross Unrealized Holding Losses	14	51
Estimated Fair Value	4,196	3,367
Debt Securities, Available-for-sale
Estimated Fair Value	1,438	1,298
Total Investments
Unrealized Holding Gains	2,904	2,149
Unrealized Holding Losses	99	192
Estimated Fair Value	5,685	4,782
Duke Energy Carolinas | NDTF | Cash and cash equivalents
Cash and Cash Equivalents
Estimated Fair Value	51	117
Duke Energy Carolinas | NDTF | Corporate debt securities
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	4	1
Gross Unrealized Holding Losses	35	62
Estimated Fair Value	390	401
Duke Energy Carolinas | NDTF | Municipal bonds
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	4	10
Estimated Fair Value	50	64
Duke Energy Carolinas | NDTF | U.S. government bonds
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	13	1
Gross Unrealized Holding Losses	33	51
Estimated Fair Value	826	685
Duke Energy Carolinas | NDTF | Other debt securities
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	1
Gross Unrealized Holding Losses	13	18
Estimated Fair Value	172	148
Progress Energy
Debt Securities, Available-for-sale
Estimated Fair Value	1,317
Total Investments
Unrealized Holding Gains	2,081	1,512
Unrealized Holding Losses	61	167
Estimated Fair Value	4,499	3,890
Progress Energy | NDTF
Equity Securities, FV-NI
Gross Unrealized Holding Gains	2,056	1,511
Gross Unrealized Holding Losses	8	54
Estimated Fair Value	3,082	2,504
Debt Securities, Available-for-sale
Estimated Fair Value	1,294	1,252
Total Investments
Unrealized Holding Gains	2,081	1,512
Unrealized Holding Losses	60	167
Estimated Fair Value	4,458	3,854
Progress Energy | NDTF | Cash and cash equivalents
Cash and Cash Equivalents
Estimated Fair Value	82	98
Progress Energy | NDTF | Corporate debt securities
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	8
Gross Unrealized Holding Losses	8	23
Estimated Fair Value	242	240
Progress Energy | NDTF | Municipal bonds
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	6
Gross Unrealized Holding Losses	12	29
Estimated Fair Value	297	266
Progress Energy | NDTF | U.S. government bonds
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	11	1
Gross Unrealized Holding Losses	32	61
Estimated Fair Value	749	738
Progress Energy | NDTF | Other debt securities
Debt Securities, Available-for-sale
Estimated Fair Value	6	8
Progress Energy | Other Investments
Debt Securities, Available-for-sale
Estimated Fair Value	23	25
Total Investments
Unrealized Holding Losses	1
Estimated Fair Value	41	36
Progress Energy | Other Investments | Cash and cash equivalents
Cash and Cash Equivalents
Estimated Fair Value	18	11
Progress Energy | Other Investments | Municipal bonds
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	1
Estimated Fair Value	23	25
Duke Energy Progress
Debt Securities, Available-for-sale
Estimated Fair Value	1,050
Total Investments
Unrealized Holding Gains	1,979	1,432
Unrealized Holding Losses	46	142
Estimated Fair Value	4,089	3,439
Duke Energy Progress | NDTF
Equity Securities, FV-NI
Gross Unrealized Holding Gains	1,956	1,431
Gross Unrealized Holding Losses	8	54
Estimated Fair Value	2,970	2,411
Debt Securities, Available-for-sale
Estimated Fair Value	1,050	963
Total Investments
Unrealized Holding Gains	1,979	1,432
Unrealized Holding Losses	46	142
Estimated Fair Value	4,075	3,430
Duke Energy Progress | NDTF | Cash and cash equivalents
Cash and Cash Equivalents
Estimated Fair Value	55	56
Duke Energy Progress | NDTF | Corporate debt securities
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	7
Gross Unrealized Holding Losses	8	22
Estimated Fair Value	229	230
Duke Energy Progress | NDTF | Municipal bonds
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	6
Gross Unrealized Holding Losses	12	29
Estimated Fair Value	297	266
Duke Energy Progress | NDTF | U.S. government bonds
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	10	1
Gross Unrealized Holding Losses	18	37
Estimated Fair Value	518	460
Duke Energy Progress | NDTF | Other debt securities
Debt Securities, Available-for-sale
Estimated Fair Value	6	7
Duke Energy Progress | Other Investments
Total Investments
Estimated Fair Value	14	9
Duke Energy Progress | Other Investments | Cash and cash equivalents
Cash and Cash Equivalents
Estimated Fair Value	14	9
Duke Energy Florida
Debt Securities, Available-for-sale
Estimated Fair Value	267
Total Investments
Unrealized Holding Gains	102	80
Unrealized Holding Losses	15	25
Estimated Fair Value	409	450
Duke Energy Florida | NDTF
Equity Securities, FV-NI
Gross Unrealized Holding Gains	100	80
Estimated Fair Value	112	93
Debt Securities, Available-for-sale
Estimated Fair Value	244	289
Total Investments
Unrealized Holding Gains	102	80
Unrealized Holding Losses	14	25
Estimated Fair Value	383	424
Duke Energy Florida | NDTF | Cash and cash equivalents
Cash and Cash Equivalents
Estimated Fair Value	27	42
Duke Energy Florida | NDTF | Corporate debt securities
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	1
Gross Unrealized Holding Losses		1
Estimated Fair Value	13	10
Duke Energy Florida | NDTF | U.S. government bonds
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	1
Gross Unrealized Holding Losses	14	24
Estimated Fair Value	231	278
Duke Energy Florida | NDTF | Other debt securities
Debt Securities, Available-for-sale
Estimated Fair Value		1
Duke Energy Florida | Other Investments
Debt Securities, Available-for-sale
Estimated Fair Value	23	25
Total Investments
Unrealized Holding Losses	1
Estimated Fair Value	26	26
Duke Energy Florida | Other Investments | Cash and cash equivalents
Cash and Cash Equivalents
Estimated Fair Value	3	1
Duke Energy Florida | Other Investments | Municipal bonds
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	1
Estimated Fair Value	23	25
Duke Energy Indiana
Debt Securities, Available-for-sale
Estimated Fair Value	64
Total Investments
Unrealized Holding Gains	5	2
Unrealized Holding Losses	1	20
Estimated Fair Value	163	140
Duke Energy Indiana | Other Investments
Equity Securities, FV-NI
Gross Unrealized Holding Gains	4	2
Gross Unrealized Holding Losses		16
Estimated Fair Value	98	79
Debt Securities, Available-for-sale
Estimated Fair Value	64	60
Duke Energy Indiana | Other Investments | Cash and cash equivalents
Cash and Cash Equivalents
Estimated Fair Value	1	1
Duke Energy Indiana | Other Investments | Corporate debt securities
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses		1
Estimated Fair Value	8	8
Duke Energy Indiana | Other Investments | Municipal bonds
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	1
Gross Unrealized Holding Losses	1	3
Estimated Fair Value	46	45
Duke Energy Indiana | Other Investments | U.S. government bonds
Debt Securities, Available-for-sale
Estimated Fair Value	$ 10	$ 7