Investments in Debt and Equity Securities (Estimated Fair Value of Investments in Debt and Equity Securities) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale
Estimated Fair Value	$ 2,858
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	4,515	$ 3,682
Unrealized Holding Losses	259	395
Estimated Fair Value	10,071	9,051
NDTF
Cash and Cash Equivalents
Estimated Fair Value	142	215
Equity Securities, FV-NI
Gross Unrealized Holding Gains	4,483	3,658
Gross Unrealized Holding Losses	34	105
Estimated Fair Value	6,836	5,871
Debt Securities, Available-for-sale
Estimated Fair Value	2,593	2,550
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	4,486	3,661
Unrealized Holding Losses	237	359
Estimated Fair Value	9,571	8,636
Other Investments
Cash and Cash Equivalents
Estimated Fair Value	89	22
Equity Securities, FV-NI
Gross Unrealized Holding Gains	29	21
Gross Unrealized Holding Losses	6	16
Estimated Fair Value	146	128
Debt Securities, Available-for-sale
Estimated Fair Value	265	265
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	29	21
Unrealized Holding Losses	22	36
Estimated Fair Value	500	415
Duke Energy Carolinas
Debt Securities, Available-for-sale
Estimated Fair Value	1,334
Duke Energy Carolinas | NDTF
Cash and Cash Equivalents
Estimated Fair Value	53	117
Equity Securities, FV-NI
Gross Unrealized Holding Gains	2,630	2,147
Gross Unrealized Holding Losses	19	51
Estimated Fair Value	3,945	3,367
Debt Securities, Available-for-sale
Estimated Fair Value	1,334	1,298
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	2,631	2,149
Unrealized Holding Losses	135	192
Estimated Fair Value	5,332	4,782
Progress Energy
Debt Securities, Available-for-sale
Estimated Fair Value	1,284
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	1,855	1,512
Unrealized Holding Losses	102	167
Estimated Fair Value	4,272	3,890
Progress Energy | NDTF
Cash and Cash Equivalents
Estimated Fair Value	89	98
Equity Securities, FV-NI
Gross Unrealized Holding Gains	1,853	1,511
Gross Unrealized Holding Losses	15	54
Estimated Fair Value	2,891	2,504
Debt Securities, Available-for-sale
Estimated Fair Value	1,259	1,252
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	1,855	1,512
Unrealized Holding Losses	102	167
Estimated Fair Value	4,239	3,854
Progress Energy | Other Investments
Cash and Cash Equivalents
Estimated Fair Value	8	11
Debt Securities, Available-for-sale
Estimated Fair Value	25	25
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Estimated Fair Value	33	36
Duke Energy Progress
Debt Securities, Available-for-sale
Estimated Fair Value	968
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	1,760	1,432
Unrealized Holding Losses	81	142
Estimated Fair Value	3,833	3,439
Duke Energy Progress | NDTF
Cash and Cash Equivalents
Estimated Fair Value	77	56
Equity Securities, FV-NI
Gross Unrealized Holding Gains	1,758	1,431
Gross Unrealized Holding Losses	15	54
Estimated Fair Value	2,783	2,411
Debt Securities, Available-for-sale
Estimated Fair Value	968	963
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	1,760	1,432
Unrealized Holding Losses	81	142
Estimated Fair Value	3,828	3,430
Duke Energy Progress | Other Investments
Cash and Cash Equivalents
Estimated Fair Value	5	9
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Estimated Fair Value	5	9
Duke Energy Florida
Debt Securities, Available-for-sale
Estimated Fair Value	316
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	95	80
Unrealized Holding Losses	21	25
Estimated Fair Value	438	450
Duke Energy Florida | NDTF
Cash and Cash Equivalents
Estimated Fair Value	12	42
Equity Securities, FV-NI
Gross Unrealized Holding Gains	95	80
Estimated Fair Value	108	93
Debt Securities, Available-for-sale
Estimated Fair Value	291	289
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	95	80
Unrealized Holding Losses	21	25
Estimated Fair Value	411	424
Duke Energy Florida | Other Investments
Cash and Cash Equivalents
Estimated Fair Value	2	1
Debt Securities, Available-for-sale
Estimated Fair Value	25	25
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Estimated Fair Value	27	26
Duke Energy Indiana
Debt Securities, Available-for-sale
Estimated Fair Value	62
Duke Energy Indiana | Other Investments
Cash and Cash Equivalents
Estimated Fair Value		1
Equity Securities, FV-NI
Gross Unrealized Holding Gains	4	2
Gross Unrealized Holding Losses	6	16
Estimated Fair Value	91	79
Debt Securities, Available-for-sale
Estimated Fair Value	62	60
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	4	2
Unrealized Holding Losses	8	20
Estimated Fair Value	153	140
Corporate debt securities | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	2	1
Gross Unrealized Holding Losses	67	85
Estimated Fair Value	619	641
Corporate debt securities | Other Investments
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	10	12
Estimated Fair Value	84	84
Corporate debt securities | Duke Energy Carolinas | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	1	1
Gross Unrealized Holding Losses	49	62
Estimated Fair Value	393	401
Corporate debt securities | Progress Energy | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	1
Gross Unrealized Holding Losses	18	23
Estimated Fair Value	226	240
Corporate debt securities | Duke Energy Progress | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	1
Gross Unrealized Holding Losses	17	22
Estimated Fair Value	216	230
Corporate debt securities | Duke Energy Florida | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	1	1
Estimated Fair Value	10	10
Corporate debt securities | Duke Energy Indiana | Other Investments
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 Losses	27	39
Estimated Fair Value	324	330
Municipal bonds | Other Investments
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	2	3
Estimated Fair Value	80	78
Municipal bonds | Duke Energy Carolinas | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	5	10
Estimated Fair Value	52	64
Municipal bonds | Progress Energy | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	22	29
Estimated Fair Value	272	266
Municipal bonds | Progress Energy | Other Investments
Debt Securities, Available-for-sale
Estimated Fair Value	25	25
Municipal bonds | Duke Energy Progress | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	22	29
Estimated Fair Value	272	266
Municipal bonds | Duke Energy Florida | Other Investments
Debt Securities, Available-for-sale
Estimated Fair Value	25	25
Municipal bonds | Duke Energy Indiana | Other Investments
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	2	3
Estimated Fair Value	47	45
U.S. government bonds | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	1	2
Gross Unrealized Holding Losses	92	112
Estimated Fair Value	1,495	1,423
U.S. government bonds | Other Investments
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	1	2
Estimated Fair Value	48	62
U.S. government bonds | Duke Energy Carolinas | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains		1
Gross Unrealized Holding Losses	45	51
Estimated Fair Value	738	685
U.S. government bonds | Progress Energy | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	1	1
Gross Unrealized Holding Losses	47	61
Estimated Fair Value	757	738
U.S. government bonds | Duke Energy Progress | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	1	1
Gross Unrealized Holding Losses	27	37
Estimated Fair Value	476	460
U.S. government bonds | Duke Energy Florida | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	20	24
Estimated Fair Value	281	278
U.S. government bonds | Duke Energy Indiana | Other Investments
Debt Securities, Available-for-sale
Estimated Fair Value	6	7
Other debt securities | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	17	18
Estimated Fair Value	155	156
Other debt securities | Other Investments
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	3	3
Estimated Fair Value	53	41
Other debt securities | Duke Energy Carolinas | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	17	18
Estimated Fair Value	151	148
Other debt securities | Progress Energy | NDTF
Debt Securities, Available-for-sale
Estimated Fair Value	4	8
Other debt securities | Duke Energy Progress | NDTF
Debt Securities, Available-for-sale
Estimated Fair Value	$ 4	7
Other debt securities | Duke Energy Florida | NDTF
Debt Securities, Available-for-sale
Estimated Fair Value		$ 1