Fair Value Measurements (Fair Value Measurement Amounts for Assets and Liabilities) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	$ 2,858
Derivative assets	322	$ 795
Total assets	10,393	9,846
Derivative liabilities	(509)	(437)
Net assets (liabilities)	9,884	9,409
NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	142	215
Estimated Fair Value	6,836	5,871
Debt securities, available-for-sale	2,593	2,550
NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated Fair Value	6,836	5,871
Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	89	22
Estimated Fair Value	146	128
Debt securities, available-for-sale	265	265
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	1	1
Total assets	8,023	7,030
Derivative liabilities	(5)	(16)
Net assets (liabilities)	8,018	7,014
Level 1 | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	142	215
Debt securities, available-for-sale	804	780
Level 1 | NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated Fair Value	6,795	5,829
Level 1 | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	89	22
Estimated Fair Value	146	128
Debt securities, available-for-sale	46	55
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	280	760
Total assets	2,288	2,740
Derivative liabilities	(504)	(421)
Net assets (liabilities)	1,784	2,319
Level 2 | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	1,789	1,770
Level 2 | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	219	210
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	41	34
Total assets	41	34
Net assets (liabilities)	41	34
Not Categorized
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	41	42
Net assets (liabilities)	41	42
Not Categorized | NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated Fair Value	41	42
Duke Energy Carolinas
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	1,334
Derivative assets	62	330
Total assets	5,394	5,112
Derivative liabilities	(183)	(127)
Net assets (liabilities)	5,211	4,985
Duke Energy Carolinas | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	53	117
Estimated Fair Value	3,945	3,367
Debt securities, available-for-sale	1,334	1,298
Duke Energy Carolinas | NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated Fair Value	3,945	3,367
Duke Energy Carolinas | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	4,293	3,765
Net assets (liabilities)	4,293	3,765
Duke Energy Carolinas | Level 1 | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	53	117
Debt securities, available-for-sale	336	323
Duke Energy Carolinas | Level 1 | NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated Fair Value	3,904	3,325
Duke Energy Carolinas | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	62	330
Total assets	1,060	1,305
Derivative liabilities	(183)	(127)
Net assets (liabilities)	877	1,178
Duke Energy Carolinas | Level 2 | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	998	975
Duke Energy Carolinas | Not Categorized
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	41	42
Net assets (liabilities)	41	42
Duke Energy Carolinas | Not Categorized | NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated Fair Value	41	42
Progress Energy
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	1,284
Derivative assets	90	248
Total assets	4,362	4,138
Derivative liabilities	(146)	(66)
Net assets (liabilities)	4,216	4,072
Progress Energy | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	89	98
Estimated Fair Value	2,891	2,504
Debt securities, available-for-sale	1,259	1,252
Progress Energy | NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated Fair Value	2,891	2,504
Progress Energy | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	8	11
Debt securities, available-for-sale	25	25
Progress Energy | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	3,456	3,070
Net assets (liabilities)	3,456	3,070
Progress Energy | Level 1 | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	89	98
Debt securities, available-for-sale	468	457
Progress Energy | Level 1 | NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated Fair Value	2,891	2,504
Progress Energy | Level 1 | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	8	11
Progress Energy | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	90	248
Total assets	906	1,068
Derivative liabilities	(146)	(66)
Net assets (liabilities)	760	1,002
Progress Energy | Level 2 | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	791	795
Progress Energy | Level 2 | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	25	25
Duke Energy Progress
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	968
Derivative assets	60	230
Total assets	3,893	3,669
Derivative liabilities	(146)	(48)
Net assets (liabilities)	3,747	3,621
Duke Energy Progress | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	77	56
Estimated Fair Value	2,783	2,411
Debt securities, available-for-sale	968	963
Duke Energy Progress | NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated Fair Value	2,783	2,411
Duke Energy Progress | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	5	9
Duke Energy Progress | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	3,099	2,701
Net assets (liabilities)	3,099	2,701
Duke Energy Progress | Level 1 | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	77	56
Debt securities, available-for-sale	234	225
Duke Energy Progress | Level 1 | NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated Fair Value	2,783	2,411
Duke Energy Progress | Level 1 | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	5	9
Duke Energy Progress | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	60	230
Total assets	794	968
Derivative liabilities	(146)	(48)
Net assets (liabilities)	648	920
Duke Energy Progress | Level 2 | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	734	738
Duke Energy Florida
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	316
Derivative assets	30	17
Total assets	468	467
Derivative liabilities		(19)
Net assets (liabilities)	468	448
Duke Energy Florida | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	12	42
Estimated Fair Value	108	93
Debt securities, available-for-sale	291	289
Duke Energy Florida | NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated Fair Value	108	93
Duke Energy Florida | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	2	1
Debt securities, available-for-sale	25	25
Duke Energy Florida | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	356	368
Net assets (liabilities)	356	368
Duke Energy Florida | Level 1 | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	12	42
Debt securities, available-for-sale	234	232
Duke Energy Florida | Level 1 | NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated Fair Value	108	93
Duke Energy Florida | Level 1 | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	2	1
Duke Energy Florida | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	30	17
Total assets	112	99
Derivative liabilities		(19)
Net assets (liabilities)	112	80
Duke Energy Florida | Level 2 | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	57	57
Duke Energy Florida | Level 2 | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	25	25
Duke Energy Indiana
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	62
Derivative assets	37	110
Total assets	190	250
Derivative liabilities	(7)	(16)
Net assets (liabilities)	183	234
Duke Energy Indiana | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents		1
Estimated Fair Value	91	79
Debt securities, available-for-sale	62	60
Duke Energy Indiana | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	91	80
Derivative liabilities	(6)	(16)
Net assets (liabilities)	85	64
Duke Energy Indiana | Level 1 | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents		1
Estimated Fair Value	91	79
Duke Energy Indiana | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets		81
Total assets	62	141
Derivative liabilities	(1)
Net assets (liabilities)	61	141
Duke Energy Indiana | Level 2 | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	62	60
Duke Energy Indiana | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	37	29
Total assets	37	29
Net assets (liabilities)	37	29
Piedmont
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	1	0
Derivative liabilities	(156)	(168)
Net assets (liabilities)	(155)	(168)
Piedmont | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	1
Net assets (liabilities)	1
Piedmont | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	(156)	(168)
Net assets (liabilities)	$ (156)	$ (168)