Fair Value Measurements (Fair Value Measurement Amounts for Assets and Liabilities) (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	$ 2,820
Derivative assets	1,259	$ 320
Total assets	9,799	11,213
Derivative liabilities	(671)	(472)
Net assets (liabilities)	9,128	10,741
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	3	3
Total assets	6,512	8,667
Derivative liabilities	(18)	(13)
Net assets (liabilities)	6,494	8,654
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	1,196	293
Total assets	3,182	2,472
Derivative liabilities	(432)	(314)
Net assets (liabilities)	2,750	2,158
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	60	24
Total assets	60	24
Derivative liabilities	(221)	(145)
Net assets (liabilities)	(161)	(121)
Not Categorized
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	45	50
Net assets (liabilities)	45	50
NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	120	160
Equity securities, FV-NI	5,447	7,350
Debt securities, available-for-sale	2,556	2,891
NDTF | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	120	160
Debt securities, available-for-sale	778	967
NDTF | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	1,778	1,924
NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	5,447	7,350
NDTF equity securities | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	5,402	7,300
NDTF equity securities | Not Categorized
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	45	50
Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	37	36
Equity securities, FV-NI	116	156
Debt securities, available-for-sale	264	300
Other Investments | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	37	36
Equity securities, FV-NI	116	156
Debt securities, available-for-sale	56	45
Other Investments | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	208	255
Duke Energy Carolinas
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	1,286
Derivative assets	535	162
Total assets	5,016	5,921
Derivative liabilities	(113)	(35)
Net assets (liabilities)	4,903	5,886
Duke Energy Carolinas | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	3,426	4,607
Net assets (liabilities)	3,426	4,607
Duke Energy Carolinas | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	535	162
Total assets	1,545	1,264
Derivative liabilities	(113)	(35)
Net assets (liabilities)	1,432	1,229
Duke Energy Carolinas | Not Categorized
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	45	50
Net assets (liabilities)	45	50
Duke Energy Carolinas | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	41	53
Equity securities, FV-NI	3,154	4,265
Debt securities, available-for-sale	1,286	1,441
Duke Energy Carolinas | NDTF | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	41	53
Debt securities, available-for-sale	276	339
Duke Energy Carolinas | NDTF | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	1,010	1,102
Duke Energy Carolinas | NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	3,154	4,265
Duke Energy Carolinas | NDTF equity securities | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	3,109	4,215
Duke Energy Carolinas | NDTF equity securities | Not Categorized
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	45	50
Progress Energy
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	1,295
Derivative assets	437	124
Total assets	4,117	4,812
Derivative liabilities	(9)	(24)
Net assets (liabilities)	4,108	4,788
Progress Energy | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	2,887	3,840
Net assets (liabilities)	2,887	3,840
Progress Energy | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	437	124
Total assets	1,230	972
Derivative liabilities	(9)	(24)
Net assets (liabilities)	1,221	948
Progress Energy | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	79	107
Equity securities, FV-NI	2,293	3,085
Debt securities, available-for-sale	1,270	1,450
Progress Energy | NDTF | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	79	107
Debt securities, available-for-sale	502	628
Progress Energy | NDTF | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	768	822
Progress Energy | NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	2,293	3,085
Progress Energy | NDTF equity securities | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	2,293	3,085
Progress Energy | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	13	20
Debt securities, available-for-sale	25	26
Progress Energy | Other Investments | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	13	20
Progress Energy | Other Investments | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	25	26
Duke Energy Progress
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	951
Derivative assets	415	124
Total assets	3,630	4,229
Derivative liabilities	(9)	(10)
Net assets (liabilities)	3,621	4,219
Duke Energy Progress | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	2,507	3,369
Net assets (liabilities)	2,507	3,369
Duke Energy Progress | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	415	124
Total assets	1,123	860
Derivative liabilities	(9)	(10)
Net assets (liabilities)	1,114	850
Duke Energy Progress | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	47	94
Equity securities, FV-NI	2,206	2,970
Debt securities, available-for-sale	951	1,025
Duke Energy Progress | NDTF | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	47	94
Debt securities, available-for-sale	243	289
Duke Energy Progress | NDTF | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	708	736
Duke Energy Progress | NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	2,206	2,970
Duke Energy Progress | NDTF equity securities | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	2,206	2,970
Duke Energy Progress | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	11	16
Duke Energy Progress | Other Investments | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	11	16
Duke Energy Florida
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	344
Derivative assets	22
Total assets	486	582
Derivative liabilities		(14)
Net assets (liabilities)	486	568
Duke Energy Florida | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	379	470
Net assets (liabilities)	379	470
Duke Energy Florida | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	22
Total assets	107	112
Derivative liabilities		(14)
Net assets (liabilities)	107	98
Duke Energy Florida | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	32	13
Equity securities, FV-NI	87	115
Debt securities, available-for-sale	319	425
Duke Energy Florida | NDTF | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	32	13
Debt securities, available-for-sale	259	339
Duke Energy Florida | NDTF | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	60	86
Duke Energy Florida | NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	87	115
Duke Energy Florida | NDTF equity securities | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	87	115
Duke Energy Florida | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	1	3
Debt securities, available-for-sale	25	26
Duke Energy Florida | Other Investments | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	1	3
Duke Energy Florida | Other Investments | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	25	26
Duke Energy Indiana
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	59
Derivative assets	131	23
Total assets	263	184
Derivative liabilities	(18)	(27)
Net assets (liabilities)	245	157
Duke Energy Indiana | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	2	1
Total assets	75	98
Derivative liabilities	(18)	(13)
Net assets (liabilities)	57	85
Duke Energy Indiana | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	73
Total assets	132	64
Derivative liabilities		(14)
Net assets (liabilities)	132	50
Duke Energy Indiana | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	56	22
Total assets	56	22
Net assets (liabilities)	56	22
Duke Energy Indiana | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	1
Equity securities, FV-NI	72	97
Debt securities, available-for-sale	59	64
Duke Energy Indiana | Other Investments | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	1
Equity securities, FV-NI	72	97
Duke Energy Indiana | Other Investments | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	59	64
Piedmont
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets		3
Derivative liabilities	(171)	(139)
Net assets (liabilities)	(171)	(136)
Piedmont | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets		3
Net assets (liabilities)		3
Piedmont | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	(171)	(139)
Net assets (liabilities)	$ (171)	$ (139)