Duke Energy (DUK) 10-Q10 May 212021 Q1 Quarterly reportFinancial data

Company Profile

Cover Page

Cover Page - shares	3 Months Ended
Cover Page - shares	Mar. 31, 2021	Apr. 30, 2021
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	1-32853
Entity Registrant Name	DUKE ENERGY CORPORATION
Entity Tax Identification Number	20-2777218
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	550 South Tryon Street
Entity Address, City or Town	Charlotte
Entity Address, State or Province	NC
Entity Address, Postal Zip Code	28202-1803
City Area Code	704
Local Phone Number	382-3853
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		769,218,956
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Entity Central Index Key	0001326160
Duke Energy Carolinas
Document Information [Line Items]
Entity File Number	1-4928
Entity Registrant Name	DUKE ENERGY CAROLINAS, LLC
Entity Tax Identification Number	56-0205520
Entity Incorporation, State or Country Code	NC
Entity Address, Address Line One	526 South Church Street
Entity Address, City or Town	Charlotte
Entity Address, State or Province	NC
Entity Address, Postal Zip Code	28202-1803
City Area Code	704
Local Phone Number	382-3853
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0000030371
Progress Energy
Document Information [Line Items]
Entity File Number	1-15929
Entity Registrant Name	PROGRESS ENERGY, INC.
Entity Tax Identification Number	56-2155481
Entity Incorporation, State or Country Code	NC
Entity Address, Address Line One	410 South Wilmington Street
Entity Address, City or Town	Raleigh
Entity Address, State or Province	NC
Entity Address, Postal Zip Code	27601-1748
City Area Code	704
Local Phone Number	382-3853
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0001094093
Duke Energy Progress
Document Information [Line Items]
Entity File Number	1-3382
Entity Registrant Name	DUKE ENERGY PROGRESS, LLC
Entity Tax Identification Number	56-0165465
Entity Incorporation, State or Country Code	NC
Entity Address, Address Line One	410 South Wilmington Street
Entity Address, City or Town	Raleigh
Entity Address, State or Province	NC
Entity Address, Postal Zip Code	27601-1748
City Area Code	704
Local Phone Number	382-3853
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0000017797
Duke Energy Florida
Document Information [Line Items]
Entity File Number	1-3274
Entity Registrant Name	DUKE ENERGY FLORIDA, LLC
Entity Tax Identification Number	59-0247770
Entity Incorporation, State or Country Code	FL
Entity Address, Address Line One	299 First Avenue North
Entity Address, City or Town	St. Petersburg
Entity Address, State or Province	FL
Entity Address, Postal Zip Code	33701
City Area Code	704
Local Phone Number	382-3853
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0000037637
Duke Energy Ohio
Document Information [Line Items]
Entity File Number	1-1232
Entity Registrant Name	DUKE ENERGY OHIO, INC.
Entity Tax Identification Number	31-0240030
Entity Incorporation, State or Country Code	OH
Entity Address, Address Line One	139 East Fourth Street
Entity Address, City or Town	Cincinnati
Entity Address, State or Province	OH
Entity Address, Postal Zip Code	45202
City Area Code	704
Local Phone Number	382-3853
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0000020290
Duke Energy Indiana
Document Information [Line Items]
Entity File Number	1-3543
Entity Registrant Name	DUKE ENERGY INDIANA, LLC
Entity Tax Identification Number	35-0594457
Entity Incorporation, State or Country Code	IN
Entity Address, Address Line One	1000 East Main Street
Entity Address, City or Town	Plainfield
Entity Address, State or Province	IN
Entity Address, Postal Zip Code	46168
City Area Code	704
Local Phone Number	382-3853
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0000081020
Piedmont
Document Information [Line Items]
Entity File Number	1-6196
Entity Registrant Name	PIEDMONT NATURAL GAS COMPANY, INC.
Entity Tax Identification Number	56-0556998
Entity Incorporation, State or Country Code	NC
Entity Address, Address Line One	4720 Piedmont Row Drive
Entity Address, City or Town	Charlotte
Entity Address, State or Province	NC
Entity Address, Postal Zip Code	28210
City Area Code	704
Local Phone Number	364-3120
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0000078460
Common Stock
Document Information [Line Items]
Title of 12(b) Security	Common Stock, $0.001 par value
Trading Symbol	DUK
Security Exchange Name	NYSE
Junior Subordinated Debentures 5.125% Coupon Due January 2073
Document Information [Line Items]
Title of 12(b) Security	5.125% Junior Subordinated Debentures
Trading Symbol	DUKH
Security Exchange Name	NYSE
Junior Subordinated Debentures 5.625% Coupon Due September 2078
Document Information [Line Items]
Title of 12(b) Security	5.625% Junior Subordinated Debentures
Trading Symbol	DUKB
Security Exchange Name	NYSE
Depositary Share
Document Information [Line Items]
Title of 12(b) Security	Depositary Shares
Trading Symbol	DUK PR A
Security Exchange Name	NYSE

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Millions, $ in Millions		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Operating Revenues
Regulated electric		$ 5,219	$ 5,124
Regulated natural gas		749	638
Nonregulated electric and other		182	187
Total operating revenues		6,150	5,949
Operating Expenses
Operation, maintenance and other		1,402	1,339
Depreciation and amortization		1,226	1,130
Property and other taxes		353	345
Impairment of assets and other charges			2
Total operating expenses		4,700	4,462
Gains on Sales of Other Assets and Other, net			1
Operating Income		1,450	1,488
Other Income and Expenses
Equity in (losses) earnings of unconsolidated affiliates		(17)	44
Other income and expenses, net		127	46
Total other income and expenses		110	90
Interest Expense		535	551
Income Before Income Taxes		1,025	1,027
Income Tax Expense		84	137
Net Income		941	890
Add: Net Loss Attributable to Noncontrolling Interests		51	48
Net Income and Comprehensive Income		992	938
Less: Preferred Dividends		39	39
Net Income Available to Duke Energy Corporation Common Stockholders		953	899
Other Comprehensive Income (Loss), net of tax
Pension and OPEB adjustments	[1]	2	1
Net unrealized (losses) gains on cash flow hedges	[1]	29	(81)
Unrealized (losses) gains on available-for-sale securities	[1]	(8)	1
Other Comprehensive Income (Loss), net of tax	[1]	26	(77)
Comprehensive Income		967	813
Add: Comprehensive Loss Attributable to Noncontrolling Interests		(44)	(62)
Comprehensive Income Attributable to Duke Energy		$ 1,011	$ 875
Net income attributable to Duke Energy Corporation common stockholders
Basic (in usd per share)		$ 1.25	$ 1.24
Diluted (in usd per share)		$ 1.25	$ 1.24
Weighted Average Shares Outstanding
Basic (in shares)		769	734
Diluted (in shares)		769	736
Duke Energy Carolinas
Operating Revenues
Total operating revenues		$ 1,716	$ 1,748
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas		422	453
Operation, maintenance and other		441	386
Depreciation and amortization		359	343
Property and other taxes		83	81
Impairment of assets and other charges			2
Total operating expenses		1,305	1,265
Gains on Sales of Other Assets and Other, net			1
Operating Income		411	484
Other Income and Expenses
Total other income and expenses		48	43
Interest Expense		124	123
Income Before Income Taxes		335	404
Income Tax Expense		23	65
Net Income and Comprehensive Income		312	339
Progress Energy
Operating Revenues
Total operating revenues		2,505	2,422
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas		795	763
Operation, maintenance and other		601	554
Depreciation and amortization		485	452
Property and other taxes		142	135
Total operating expenses		2,023	1,904
Gains on Sales of Other Assets and Other, net			(1)
Operating Income		482	517
Other Income and Expenses
Total other income and expenses		43	32
Interest Expense		192	206
Income Before Income Taxes		333	343
Income Tax Expense		43	60
Net Income		290	283
Other Comprehensive Income (Loss), net of tax
Net unrealized (losses) gains on cash flow hedges		1	1
Unrealized (losses) gains on available-for-sale securities		(1)	1
Other Comprehensive Income (Loss), net of tax			2
Comprehensive Income		290	285
Duke Energy Progress
Operating Revenues
Total operating revenues		1,401	1,338
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas		436	405
Operation, maintenance and other		357	305
Depreciation and amortization		285	287
Property and other taxes		49	47
Total operating expenses		1,127	1,044
Gains on Sales of Other Assets and Other, net			(1)
Operating Income		274	293
Other Income and Expenses
Total other income and expenses		24	22
Interest Expense		69	69
Income Before Income Taxes		229	246
Income Tax Expense		19	42
Net Income and Comprehensive Income		210	204
Duke Energy Florida
Operating Revenues
Total operating revenues		1,101	1,080
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas		359	358
Operation, maintenance and other		242	245
Depreciation and amortization		200	165
Property and other taxes		93	88
Total operating expenses		894	856
Operating Income		207	224
Other Income and Expenses
Total other income and expenses		18	10
Interest Expense		80	84
Income Before Income Taxes		145	150
Income Tax Expense		28	30
Net Income and Comprehensive Income		117	120
Other Comprehensive Income (Loss), net of tax
Unrealized (losses) gains on available-for-sale securities		(1)	1
Other Comprehensive Income (Loss), net of tax		(1)	1
Comprehensive Income Attributable to Duke Energy		116	121
Duke Energy Ohio
Operating Revenues
Regulated electric		363	346
Regulated natural gas		169	152
Total operating revenues		532	498
Operating Expenses
Operation, maintenance and other		108	123
Depreciation and amortization		74	68
Property and other taxes		92	83
Total operating expenses		407	398
Operating Income		125	100
Other Income and Expenses
Total other income and expenses		5	3
Interest Expense		25	24
Income Before Income Taxes		105	79
Income Tax Expense		14	14
Net Income and Comprehensive Income		91	65
Duke Energy Indiana
Operating Revenues
Total operating revenues		745	692
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas		217	194
Operation, maintenance and other		178	186
Depreciation and amortization		152	132
Property and other taxes		21	22
Total operating expenses		568	534
Operating Income		177	158
Other Income and Expenses
Total other income and expenses		9	10
Interest Expense		50	43
Income Before Income Taxes		136	125
Income Tax Expense		24	26
Net Income and Comprehensive Income		112	99
Piedmont
Operating Revenues
Total operating revenues		606	512
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas		225	162
Operation, maintenance and other		78	80
Depreciation and amortization		48	45
Property and other taxes		14	12
Total operating expenses		365	299
Operating Income		241	213
Other Income and Expenses
Equity in (losses) earnings of unconsolidated affiliates		2	2
Total other income and expenses		17	12
Interest Expense		29	27
Income Before Income Taxes		229	198
Income Tax Expense		26	20
Net Income and Comprehensive Income		203	178
Fuel used in electric generation and purchased power
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas		1,443	1,447
Fuel used in electric generation and purchased power \| Duke Energy Ohio
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas		82	87
Cost of natural gas
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas		276	199
Cost of natural gas \| Duke Energy Ohio
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas		$ 51	$ 37

[1]	Net of income tax impacts of approximately $8 million and $23 million for the three months ended March 31, 2021, and 2020, respectively.

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Net income		$ 941	$ 890
Other Comprehensive Loss, net of tax
Pension and OPEB adjustments	[1]	2	1
Net unrealized gains (losses) on cash flow hedges	[1]	29	(81)
Reclassification into earnings from cash flow hedges	[1]	3	2
Unrealized (losses) gains on available-for-sale securities	[1]	(8)	1
Other Comprehensive Income (Loss), net of tax	[1]	26	(77)
Comprehensive Income		967	813
Add: Comprehensive Loss Attributable to Noncontrolling Interests		44	62
Comprehensive Income Attributable to Duke Energy		1,011	875
Less: Preferred Dividends		39	39
Comprehensive Income Available to Duke Energy Corporation Common Stockholders		$ 972	$ 836

[1]	Net of income tax impacts of approximately $8 million and $23 million for the three months ended March 31, 2021, and 2020, respectively.

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Other comprehensive income (loss), tax	$ 8	$ 23

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Current Assets
Cash and cash equivalents	$ 379	$ 259
Receivables (net of allowance for doubtful accounts)	950	1,009
Receivables of VIEs (net of allowance for doubtful accounts)	1,834	2,144
Inventory	3,076	3,167
Regulatory assets (includes amounts related to VIEs)	1,650	1,641
Other (includes amounts related to VIEs)	619	462
Total current assets	8,508	8,682
Property, Plant and Equipment
Cost	157,372	155,580
Accumulated depreciation and amortization	(49,772)	(48,827)
Generation facilities to be retired, net	29	29
Net property, plant and equipment	107,629	106,782
Other Noncurrent Assets
Goodwill	19,303	19,303
Regulatory assets (includes amounts related to VIEs)	12,441	12,421
Nuclear decommissioning trust funds	9,410	9,114
Operating lease right-of-use assets, net	1,540	1,524
Investments in equity method unconsolidated affiliates	919	961
Other (includes amounts related to VIEs)	3,715	3,601
Total other noncurrent assets	47,328	46,924
Total Assets	163,465	162,388
Current Liabilities
Accounts payable	2,497	3,144
Notes payable and commercial paper	4,064	2,873
Taxes accrued	574	482
Interest accrued	536	537
Current maturities of long-term debt (includes amounts related to VIEs)	5,586	4,238
Asset retirement obligations	709	718
Regulatory liabilities	1,509	1,377
Other	1,858	2,936
Total current liabilities	17,333	16,305
Long-Term Debt (includes amounts related to VIEs)	54,768	55,625
Other Noncurrent Liabilities
Deferred income taxes	9,459	9,244
Asset retirement obligations	12,299	12,286
Regulatory liabilities	15,070	15,029
Operating lease liabilities	1,352	1,340
Accrued pension and other post-retirement benefit costs	1,010	969
Investment tax credits	747	687
Other (includes amounts related to VIEs)	1,769	1,719
Total other noncurrent liabilities	41,706	41,274
Commitments and Contingencies
Equity
Common stock	1	1
Additional paid-in capital	43,761	43,767
Retained earnings	2,680	2,471
Accumulated other comprehensive loss	(218)	(237)
Total Duke Energy Corporation stockholders' equity	48,186	47,964
Noncontrolling interests	1,472	1,220
Total equity	49,658	49,184
Total Liabilities and Equity	163,465	162,388
Variable Interest Entity
Current Assets
Regulatory assets (includes amounts related to VIEs)	54	53
Other (includes amounts related to VIEs)	333	296
Other Noncurrent Assets
Regulatory assets (includes amounts related to VIEs)	927	937
Other (includes amounts related to VIEs)	82	81
Current Liabilities
Current maturities of long-term debt (includes amounts related to VIEs)	472	472
Long-Term Debt (includes amounts related to VIEs)	3,686	3,535
Other Noncurrent Liabilities
Other (includes amounts related to VIEs)	331	316
Duke Energy Carolinas
Current Assets
Cash and cash equivalents	12	21
Receivables (net of allowance for doubtful accounts)	171	247
Receivables of VIEs (net of allowance for doubtful accounts)	613	696
Receivables from affiliated companies	119	124
Inventory	1,021	1,010
Regulatory assets (includes amounts related to VIEs)	433	473
Other (includes amounts related to VIEs)	90	20
Total current assets	2,459	2,591
Property, Plant and Equipment
Cost	51,027	50,640
Accumulated depreciation and amortization	(17,690)	(17,453)
Net property, plant and equipment	33,337	33,187
Other Noncurrent Assets
Regulatory assets (includes amounts related to VIEs)	3,028	2,996
Nuclear decommissioning trust funds	5,147	4,977
Operating lease right-of-use assets, net	105	110
Other (includes amounts related to VIEs)	1,185	1,187
Total other noncurrent assets	9,465	9,270
Total Assets	45,261	45,048
Current Liabilities
Accounts payable	643	1,000
Accounts payable to affiliated companies	206	199
Notes payable to affiliated companies	508	506
Taxes accrued	138	76
Interest accrued	128	117
Current maturities of long-term debt (includes amounts related to VIEs)	507	506
Asset retirement obligations	258	264
Regulatory liabilities	559	473
Other	440	546
Total current liabilities	3,387	3,687
Long-Term Debt (includes amounts related to VIEs)	11,522	11,412
Long-Term Debt Payable to Affiliated Companies	300	300
Other Noncurrent Liabilities
Deferred income taxes	3,913	3,842
Asset retirement obligations	5,117	5,086
Regulatory liabilities	6,540	6,535
Operating lease liabilities	93	97
Accrued pension and other post-retirement benefit costs	72	73
Investment tax credits	235	236
Other (includes amounts related to VIEs)	616	626
Total other noncurrent liabilities	16,586	16,495
Commitments and Contingencies
Equity
Member's equity	13,473	13,161
Accumulated other comprehensive loss	(7)	(7)
Member's Equity	13,466	13,154
Total Liabilities and Equity	45,261	45,048
Progress Energy
Current Assets
Cash and cash equivalents	74	59
Receivables (net of allowance for doubtful accounts)	166	228
Receivables of VIEs (net of allowance for doubtful accounts)	749	901
Receivables from affiliated companies	76	157
Inventory	1,336	1,375
Regulatory assets (includes amounts related to VIEs)	821	758
Other (includes amounts related to VIEs)	257	109
Total current assets	3,479	3,587
Property, Plant and Equipment
Cost	58,546	57,892
Accumulated depreciation and amortization	(18,718)	(18,368)
Generation facilities to be retired, net	29	29
Net property, plant and equipment	39,857	39,553
Other Noncurrent Assets
Goodwill	3,655	3,655
Regulatory assets (includes amounts related to VIEs)	5,749	5,775
Nuclear decommissioning trust funds	4,263	4,137
Operating lease right-of-use assets, net	720	690
Other (includes amounts related to VIEs)	1,267	1,227
Total other noncurrent assets	15,654	15,484
Total Assets	58,990	58,624
Current Liabilities
Accounts payable	796	919
Accounts payable to affiliated companies	321	289
Notes payable to affiliated companies	2,844	2,969
Taxes accrued	143	121
Interest accrued	187	202
Current maturities of long-term debt (includes amounts related to VIEs)	2,127	1,426
Asset retirement obligations	267	283
Regulatory liabilities	702	640
Other	744	793
Total current liabilities	8,131	7,642
Long-Term Debt (includes amounts related to VIEs)	17,056	17,688
Long-Term Debt Payable to Affiliated Companies	150	150
Other Noncurrent Liabilities
Deferred income taxes	4,489	4,396
Asset retirement obligations	5,859	5,866
Regulatory liabilities	5,126	5,051
Operating lease liabilities	648	623
Accrued pension and other post-retirement benefit costs	501	505
Other (includes amounts related to VIEs)	500	462
Total other noncurrent liabilities	17,123	16,903
Commitments and Contingencies
Equity
Additional paid-in capital	9,143	9,143
Retained earnings	7,400	7,109
Accumulated other comprehensive loss	(15)	(15)
Total Duke Energy Corporation stockholders' equity	16,528	16,237
Noncontrolling interests	2	4
Total equity	16,530	16,241
Total Liabilities and Equity	58,990	58,624
Progress Energy \| Variable Interest Entity
Current Assets
Regulatory assets (includes amounts related to VIEs)	54	53
Other (includes amounts related to VIEs)	14	39
Other Noncurrent Assets
Regulatory assets (includes amounts related to VIEs)	927	937
Current Liabilities
Current maturities of long-term debt (includes amounts related to VIEs)	305	305
Long-Term Debt (includes amounts related to VIEs)	1,322	1,252
Duke Energy Progress
Current Assets
Cash and cash equivalents	46	39
Receivables (net of allowance for doubtful accounts)	80	132
Receivables of VIEs (net of allowance for doubtful accounts)	422	500
Receivables from affiliated companies	70	50
Inventory	882	911
Regulatory assets (includes amounts related to VIEs)	469	492
Other (includes amounts related to VIEs)	138	60
Total current assets	2,107	2,184
Property, Plant and Equipment
Cost	36,077	35,759
Accumulated depreciation and amortization	(13,064)	(12,801)
Generation facilities to be retired, net	29	29
Net property, plant and equipment	23,042	22,987
Other Noncurrent Assets
Regulatory assets (includes amounts related to VIEs)	4,033	3,976
Nuclear decommissioning trust funds	3,645	3,500
Operating lease right-of-use assets, net	386	346
Other (includes amounts related to VIEs)	759	740
Total other noncurrent assets	8,823	8,562
Total Assets	33,972	33,733
Current Liabilities
Accounts payable	339	454
Accounts payable to affiliated companies	225	215
Notes payable to affiliated companies	163	295
Taxes accrued	73	85
Interest accrued	71	99
Current maturities of long-term debt (includes amounts related to VIEs)	1,302	603
Asset retirement obligations	267	283
Regulatory liabilities	618	530
Other	383	411
Total current liabilities	3,441	2,975
Long-Term Debt (includes amounts related to VIEs)	7,904	8,505
Long-Term Debt Payable to Affiliated Companies	150	150
Other Noncurrent Liabilities
Deferred income taxes	2,374	2,298
Asset retirement obligations	5,366	5,352
Regulatory liabilities	4,454	4,394
Operating lease liabilities	356	323
Accrued pension and other post-retirement benefit costs	240	242
Investment tax credits	131	132
Other (includes amounts related to VIEs)	86	102
Total other noncurrent liabilities	13,007	12,843
Commitments and Contingencies
Equity
Member's Equity	9,470	9,260
Total Liabilities and Equity	33,972	33,733
Duke Energy Florida
Current Assets
Cash and cash equivalents	22	11
Receivables (net of allowance for doubtful accounts)	84	94
Receivables of VIEs (net of allowance for doubtful accounts)	327	401
Receivables from affiliated companies	7	3
Inventory	455	464
Regulatory assets (includes amounts related to VIEs)	352	265
Other (includes amounts related to VIEs)	82	41
Total current assets	1,329	1,279
Property, Plant and Equipment
Cost	22,459	22,123
Accumulated depreciation and amortization	(5,646)	(5,560)
Net property, plant and equipment	16,813	16,563
Other Noncurrent Assets
Regulatory assets (includes amounts related to VIEs)	1,717	1,799
Nuclear decommissioning trust funds	617	637
Operating lease right-of-use assets, net	333	344
Other (includes amounts related to VIEs)	355	335
Total other noncurrent assets	3,022	3,115
Total Assets	21,164	20,957
Current Liabilities
Accounts payable	457	465
Accounts payable to affiliated companies	108	85
Notes payable to affiliated companies	279	196
Taxes accrued	84	82
Interest accrued	75	69
Current maturities of long-term debt (includes amounts related to VIEs)	824	823
Regulatory liabilities	84	110
Other	356	374
Total current liabilities	2,267	2,204
Long-Term Debt (includes amounts related to VIEs)	7,060	7,092
Other Noncurrent Liabilities
Deferred income taxes	2,209	2,191
Asset retirement obligations	493	514
Regulatory liabilities	672	658
Operating lease liabilities	292	300
Accrued pension and other post-retirement benefit costs	230	231
Other (includes amounts related to VIEs)	267	209
Total other noncurrent liabilities	4,163	4,103
Commitments and Contingencies
Equity
Member's equity	7,677	7,560
Accumulated other comprehensive loss	(3)	(2)
Member's Equity	7,674	7,558
Total Liabilities and Equity	21,164	20,957
Duke Energy Florida \| Variable Interest Entity
Current Assets
Regulatory assets (includes amounts related to VIEs)	54	53
Other (includes amounts related to VIEs)	14	39
Other Noncurrent Assets
Regulatory assets (includes amounts related to VIEs)	927	937
Current Liabilities
Current maturities of long-term debt (includes amounts related to VIEs)	305	305
Long-Term Debt (includes amounts related to VIEs)	972	1,002
Duke Energy Ohio
Current Assets
Cash and cash equivalents	18	14
Receivables (net of allowance for doubtful accounts)	98	98
Receivables from affiliated companies	60	102
Inventory	108	110
Regulatory assets (includes amounts related to VIEs)	54	39
Other (includes amounts related to VIEs)	18	31
Total current assets	356	394
Property, Plant and Equipment
Cost	11,199	11,022
Accumulated depreciation and amortization	(3,049)	(3,013)
Net property, plant and equipment	8,150	8,009
Other Noncurrent Assets
Goodwill	920	920
Regulatory assets (includes amounts related to VIEs)	620	610
Operating lease right-of-use assets, net	20	20
Other (includes amounts related to VIEs)	75	72
Total other noncurrent assets	1,635	1,622
Total Assets	10,141	10,025
Current Liabilities
Accounts payable	266	279
Accounts payable to affiliated companies	56	68
Notes payable to affiliated companies	270	169
Taxes accrued	192	247
Interest accrued	32	31
Current maturities of long-term debt (includes amounts related to VIEs)	50	50
Asset retirement obligations	8	3
Regulatory liabilities	59	65
Other	67	70
Total current liabilities	1,000	982
Long-Term Debt (includes amounts related to VIEs)	3,015	3,014
Long-Term Debt Payable to Affiliated Companies	25	25
Other Noncurrent Liabilities
Deferred income taxes	1,001	981
Asset retirement obligations	104	108
Regulatory liabilities	739	748
Operating lease liabilities	20	20
Accrued pension and other post-retirement benefit costs	114	113
Other (includes amounts related to VIEs)	97	99
Total other noncurrent liabilities	2,075	2,069
Commitments and Contingencies
Equity
Common stock	762	762
Additional paid-in capital	2,776	2,776
Retained earnings	488	397
Total Duke Energy Corporation stockholders' equity	4,026	3,935
Total Liabilities and Equity	10,141	10,025
Duke Energy Indiana
Current Assets
Cash and cash equivalents	17	7
Receivables (net of allowance for doubtful accounts)	63	55
Receivables from affiliated companies	62	112
Notes receivable from affiliated companies	51
Inventory	436	473
Regulatory assets (includes amounts related to VIEs)	151	125
Other (includes amounts related to VIEs)	34	37
Total current assets	814	809
Property, Plant and Equipment
Cost	17,548	17,382
Accumulated depreciation and amortization	(5,821)	(5,661)
Net property, plant and equipment	11,727	11,721
Other Noncurrent Assets
Regulatory assets (includes amounts related to VIEs)	1,217	1,203
Operating lease right-of-use assets, net	54	55
Other (includes amounts related to VIEs)	251	253
Total other noncurrent assets	1,522	1,511
Total Assets	14,063	14,041
Current Liabilities
Accounts payable	163	188
Accounts payable to affiliated companies	72	88
Notes payable to affiliated companies		131
Taxes accrued	122	62
Interest accrued	59	51
Current maturities of long-term debt (includes amounts related to VIEs)	123	70
Asset retirement obligations	176	168
Regulatory liabilities	119	111
Other	82	83
Total current liabilities	916	952
Long-Term Debt (includes amounts related to VIEs)	3,818	3,871
Long-Term Debt Payable to Affiliated Companies	150	150
Other Noncurrent Liabilities
Deferred income taxes	1,230	1,228
Asset retirement obligations	997	1,008
Regulatory liabilities	1,629	1,627
Operating lease liabilities	52	53
Accrued pension and other post-retirement benefit costs	172	171
Investment tax credits	168	168
Other (includes amounts related to VIEs)	35	30
Total other noncurrent liabilities	4,283	4,285
Commitments and Contingencies
Equity
Member's Equity	4,896	4,783
Total Liabilities and Equity	14,063	14,041
Piedmont
Current Assets
Cash and cash equivalents	1	0
Receivables (net of allowance for doubtful accounts)	257	250
Receivables from affiliated companies	10	10
Notes receivable from affiliated companies	198	0
Inventory	37	68
Regulatory assets (includes amounts related to VIEs)	100	153
Other (includes amounts related to VIEs)	12	20
Total current assets	615	501
Property, Plant and Equipment
Cost	9,358	9,134
Accumulated depreciation and amortization	(1,809)	(1,749)
Net property, plant and equipment	7,549	7,385
Other Noncurrent Assets
Goodwill	49	49
Regulatory assets (includes amounts related to VIEs)	324	302
Operating lease right-of-use assets, net	19	20
Investments in equity method unconsolidated affiliates	88	88
Other (includes amounts related to VIEs)	274	270
Total other noncurrent assets	754	729
Total Assets	8,918	8,615
Current Liabilities
Accounts payable	166	230
Accounts payable to affiliated companies	58	79
Notes payable to affiliated companies		530
Taxes accrued	68	23
Interest accrued	37	34
Current maturities of long-term debt (includes amounts related to VIEs)	160	160
Regulatory liabilities	70	88
Other	73	69
Total current liabilities	632	1,213
Long-Term Debt (includes amounts related to VIEs)	2,967	2,620
Other Noncurrent Liabilities
Deferred income taxes	837	821
Asset retirement obligations	20	20
Regulatory liabilities	1,015	1,044
Operating lease liabilities	17	19
Accrued pension and other post-retirement benefit costs	8	8
Other (includes amounts related to VIEs)	179	155
Total other noncurrent liabilities	2,076	2,067
Commitments and Contingencies
Equity
Common stock	1,635	1,310
Retained earnings	1,608	1,405
Total Duke Energy Corporation stockholders' equity	3,243	2,715
Total Liabilities and Equity	8,918	8,615
Preferred stock, Series A
Equity
Preferred stock	973	973
Preferred stock, Series B
Equity
Preferred stock	$ 989	$ 989

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Regulatory assets (includes amounts related to VIEs)	$ 1,650	$ 1,641
Current Assets: Other	619	462
Regulatory assets (includes amounts related to VIEs)	12,441	12,421
Other Noncurrent Assets: Other	3,715	3,601
Current maturities of long-term debt (includes amounts related to VIEs)	5,586	4,238
Long-Term Debt	54,768	55,625
Other, noncurrent liabilities	$ 1,769	$ 1,719
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	2,000,000,000	2,000,000,000
Common stock, shares outstanding (in shares)	769,000,000	769,000,000
Preferred stock, Series A
Preferred stock, par value (in usd per share)	$ 0.001	$ 0.001
Preferred stock, depositary shares authorized (in shares)	40,000,000	40,000,000
Preferred stock, depositary shares outstanding (in shares)	40,000,000	40,000,000
Preferred stock, Series B
Preferred stock, par value (in usd per share)	$ 0.001	$ 0.001
Preferred stock, depositary shares authorized (in shares)	1,000,000	1,000,000
Preferred stock, depositary shares outstanding (in shares)	1,000,000	1,000,000
Variable Interest Entity
Allowance for doubtful accounts - receivables	$ 31	$ 29
Allowance for doubtful accounts - receivables of VIEs	116	117
Regulatory assets (includes amounts related to VIEs)	54	53
Current Assets: Other	333	296
Regulatory assets (includes amounts related to VIEs)	927	937
Other Noncurrent Assets: Other	82	81
Current maturities of long-term debt (includes amounts related to VIEs)	472	472
Long-Term Debt	3,686	3,535
Other, noncurrent liabilities	331	316
Duke Energy Carolinas
Allowance for doubtful accounts - receivables	2	1
Allowance for doubtful accounts - receivables of VIEs	32	22
Regulatory assets (includes amounts related to VIEs)	433	473
Current Assets: Other	90	20
Regulatory assets (includes amounts related to VIEs)	3,028	2,996
Other Noncurrent Assets: Other	1,185	1,187
Current maturities of long-term debt (includes amounts related to VIEs)	507	506
Long-Term Debt	11,522	11,412
Other, noncurrent liabilities	616	626
Progress Energy
Allowance for doubtful accounts - receivables	8	8
Regulatory assets (includes amounts related to VIEs)	821	758
Current Assets: Other	257	109
Regulatory assets (includes amounts related to VIEs)	5,749	5,775
Other Noncurrent Assets: Other	1,267	1,227
Current maturities of long-term debt (includes amounts related to VIEs)	2,127	1,426
Long-Term Debt	17,056	17,688
Other, noncurrent liabilities	$ 500	$ 462
Common stock, par value (in usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	100	100
Progress Energy \| Variable Interest Entity
Allowance for doubtful accounts - receivables of VIEs	$ 29	$ 29
Regulatory assets (includes amounts related to VIEs)	54	53
Current Assets: Other	14	39
Regulatory assets (includes amounts related to VIEs)	927	937
Current maturities of long-term debt (includes amounts related to VIEs)	305	305
Long-Term Debt	1,322	1,252
Duke Energy Progress
Allowance for doubtful accounts - receivables	4	4
Regulatory assets (includes amounts related to VIEs)	469	492
Current Assets: Other	138	60
Regulatory assets (includes amounts related to VIEs)	4,033	3,976
Other Noncurrent Assets: Other	759	740
Current maturities of long-term debt (includes amounts related to VIEs)	1,302	603
Long-Term Debt	7,904	8,505
Other, noncurrent liabilities	86	102
Duke Energy Progress \| Variable Interest Entity
Allowance for doubtful accounts - receivables of VIEs	19	19
Duke Energy Florida
Allowance for doubtful accounts - receivables	5	4
Regulatory assets (includes amounts related to VIEs)	352	265
Current Assets: Other	82	41
Regulatory assets (includes amounts related to VIEs)	1,717	1,799
Other Noncurrent Assets: Other	355	335
Current maturities of long-term debt (includes amounts related to VIEs)	824	823
Long-Term Debt	7,060	7,092
Other, noncurrent liabilities	267	209
Duke Energy Florida \| Variable Interest Entity
Allowance for doubtful accounts - receivables of VIEs	10	10
Regulatory assets (includes amounts related to VIEs)	54	53
Current Assets: Other	14	39
Regulatory assets (includes amounts related to VIEs)	927	937
Current maturities of long-term debt (includes amounts related to VIEs)	305	305
Long-Term Debt	972	1,002
Duke Energy Ohio
Allowance for doubtful accounts - receivables	4	4
Regulatory assets (includes amounts related to VIEs)	54	39
Current Assets: Other	18	31
Regulatory assets (includes amounts related to VIEs)	620	610
Other Noncurrent Assets: Other	75	72
Current maturities of long-term debt (includes amounts related to VIEs)	50	50
Long-Term Debt	3,015	3,014
Other, noncurrent liabilities	$ 97	$ 99
Common stock, par value (in usd per share)	$ 8.50	$ 8.50
Common stock, shares authorized (in shares)	120,000,000	120,000,000
Common stock, shares outstanding (in shares)	90,000,000	90,000,000
Duke Energy Indiana
Allowance for doubtful accounts - receivables	$ 3	$ 3
Regulatory assets (includes amounts related to VIEs)	151	125
Current Assets: Other	34	37
Regulatory assets (includes amounts related to VIEs)	1,217	1,203
Other Noncurrent Assets: Other	251	253
Current maturities of long-term debt (includes amounts related to VIEs)	123	70
Long-Term Debt	3,818	3,871
Other, noncurrent liabilities	35	30
Piedmont
Allowance for doubtful accounts - receivables	14	12
Regulatory assets (includes amounts related to VIEs)	100	153
Current Assets: Other	12	20
Regulatory assets (includes amounts related to VIEs)	324	302
Other Noncurrent Assets: Other	274	270
Current maturities of long-term debt (includes amounts related to VIEs)	160	160
Long-Term Debt	2,967	2,620
Other, noncurrent liabilities	$ 179	$ 155
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares outstanding (in shares)	100,000,000	100,000,000

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 941	$ 890
Net income	992	938
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	1,385	1,301
Equity in losses (earnings) of unconsolidated affiliates	17	(44)
Equity component of AFUDC	(42)	(40)
Deferred income taxes	86	422
Payments for asset retirement obligations	(114)	(132)
(Increase) decrease in
Receivables	377	466
Inventory	91	(92)
Other current assets	(47)	(131)
Increase (decrease) in
Accounts payable	(467)	(657)
Taxes accrued	104	113
Other current liabilities	(263)	(455)
Other assets	51	(37)
Other liabilities	(31)	(50)
Net cash provided by operating activities	2,088	1,554
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(2,215)	(2,832)
Contributions to equity method investments		(77)
Purchases of debt and equity securities	(1,584)	(1,392)
Proceeds from sales and maturities of debt and equity securities	1,601	1,347
Disbursements to canceled equity method investments	(855)
Other	(84)	(68)
Net cash used in investing activities	(3,137)	(3,022)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	608	1,954
Proceeds from the issuance of common stock	5	40
Payments for the redemption of long-term debt	(76)	(292)
Proceeds from the issuance of short-term debt with original maturities greater than 90 days	50	1,784
Payments for the redemption of short-term debt with original maturities greater than 90 days	(909)	(17)
Notes payable and commercial paper	2,046	(198)
Contributions from noncontrolling interests	303	103
Dividends paid	(783)	(707)
Other	(59)	(74)
Net cash provided by financing activities	1,185	2,593
Net increase in cash, cash equivalents and restricted cash	136	1,125
Cash, cash equivalents and restricted cash at beginning of period	556	573
Cash, cash equivalents and restricted cash at end of period	692	1,698
Significant non-cash transactions:
Accrued capital expenditures	921	934
Non-cash dividends		27
Duke Energy Carolinas
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	312	339
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	428	414
Equity component of AFUDC	(16)	(14)
Deferred income taxes	(8)	22
Payments for asset retirement obligations	(35)	(41)
(Increase) decrease in
Receivables	156	156
Receivables from affiliated companies	5	27
Inventory	(11)	(72)
Other current assets	(48)	96
Increase (decrease) in
Accounts payable	(255)	(253)
Accounts payable to affiliated companies	7	15
Taxes accrued	62	87
Other current liabilities	(77)	(108)
Other assets	43	(60)
Other liabilities	(17)	(10)
Net cash provided by operating activities	546	598
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(622)	(724)
Purchases of debt and equity securities	(1,128)	(607)
Proceeds from sales and maturities of debt and equity securities	1,128	607
Notes receivable from affiliated companies		(436)
Other	(43)	(18)
Net cash used in investing activities	(665)	(1,178)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	142	910
Payments for the redemption of long-term debt	(33)	(2)
Notes payable to affiliated companies	2	(29)
Distributions to parent		(300)
Other	(1)	(1)
Net cash provided by financing activities	110	578
Net increase in cash, cash equivalents and restricted cash	(9)	(2)
Cash, cash equivalents and restricted cash at beginning of period	21	18
Cash, cash equivalents and restricted cash at end of period	12	16
Significant non-cash transactions:
Accrued capital expenditures	268	254
Progress Energy
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	290	283
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	575	552
Equity component of AFUDC	(13)	(14)
Deferred income taxes	79	80
Payments for asset retirement obligations	(69)	(79)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	6	1
Receivables	214	149
Receivables from affiliated companies	81	27
Inventory	39	(40)
Other current assets	(150)	43
Increase (decrease) in
Accounts payable	(69)	(211)
Accounts payable to affiliated companies	32	19
Taxes accrued	23	71
Other current liabilities	(60)	(128)
Other assets	(27)	(38)
Other liabilities	(64)	(56)
Net cash provided by operating activities	887	659
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(796)	(972)
Purchases of debt and equity securities	(517)	(651)
Proceeds from sales and maturities of debt and equity securities	537	643
Notes receivable from affiliated companies		164
Other	(59)	(39)
Net cash used in investing activities	(835)	(855)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	98
Payments for the redemption of long-term debt	(34)	(283)
Notes payable to affiliated companies	(125)	479
Other	(2)	(1)
Net cash provided by financing activities	(63)	195
Net increase in cash, cash equivalents and restricted cash	(11)	(1)
Cash, cash equivalents and restricted cash at beginning of period	200	126
Cash, cash equivalents and restricted cash at end of period	189	125
Significant non-cash transactions:
Accrued capital expenditures	317	310
Duke Energy Progress
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	210	204
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	331	331
Equity component of AFUDC	(8)	(10)
Deferred income taxes	6	43
Payments for asset retirement obligations	(46)	(75)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	2	(2)
Receivables	131	133
Receivables from affiliated companies	(20)	2
Inventory	29	(22)
Other current assets	(21)	54
Increase (decrease) in
Accounts payable	(62)	(220)
Accounts payable to affiliated companies	10	5
Taxes accrued	(12)	26
Other current liabilities	(25)	(73)
Other assets	(35)	(48)
Other liabilities	(15)	(8)
Net cash provided by operating activities	475	340
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(400)	(466)
Purchases of debt and equity securities	(382)	(550)
Proceeds from sales and maturities of debt and equity securities	380	540
Other	(29)	(16)
Net cash used in investing activities	(431)	(492)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	98
Payments for the redemption of long-term debt	(2)	(1)
Notes payable to affiliated companies	(132)	163
Other	(1)
Net cash provided by financing activities	(37)	162
Net increase in cash, cash equivalents and restricted cash	7	10
Cash, cash equivalents and restricted cash at beginning of period	39	22
Cash, cash equivalents and restricted cash at end of period	46	32
Significant non-cash transactions:
Accrued capital expenditures	96	87
Duke Energy Florida
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	117	120
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	243	219
Equity component of AFUDC	(4)	(4)
Deferred income taxes	74	34
Payments for asset retirement obligations	(24)	(5)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	2	3
Receivables	83	15
Receivables from affiliated companies	(4)
Inventory	10	(19)
Other current assets	(101)	7
Increase (decrease) in
Accounts payable	(7)	11
Accounts payable to affiliated companies	23	(20)
Taxes accrued	3	31
Other current liabilities	(41)	(58)
Other assets	12	13
Other liabilities	(48)	(46)
Net cash provided by operating activities	338	301
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(396)	(506)
Purchases of debt and equity securities	(134)	(101)
Proceeds from sales and maturities of debt and equity securities	157	103
Notes receivable from affiliated companies		173
Other	(30)	(23)
Net cash used in investing activities	(403)	(354)
CASH FLOWS FROM FINANCING ACTIVITIES
Payments for the redemption of long-term debt	(33)	(282)
Notes payable to affiliated companies	83	305
Other		(1)
Net cash provided by financing activities	50	22
Net increase in cash, cash equivalents and restricted cash	(15)	(31)
Cash, cash equivalents and restricted cash at beginning of period	50	56
Cash, cash equivalents and restricted cash at end of period	35	25
Significant non-cash transactions:
Accrued capital expenditures	222	223
Duke Energy Ohio
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	91	65
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	75	69
Equity component of AFUDC	(2)	(1)
Deferred income taxes	12	14
(Increase) decrease in
Receivables		1
Receivables from affiliated companies	5	40
Inventory	2	14
Other current assets	(5)	8
Increase (decrease) in
Accounts payable	8	(19)
Accounts payable to affiliated companies	(12)
Taxes accrued	(55)	(49)
Other current liabilities	(8)	2
Other assets	(16)	(2)
Other liabilities	1	(5)
Net cash provided by operating activities	96	137
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(220)	(217)
Notes receivable from affiliated companies	37
Other	(10)	(10)
Net cash used in investing activities	(193)	(227)
CASH FLOWS FROM FINANCING ACTIVITIES
Notes payable to affiliated companies	101	87
Net cash provided by financing activities	101	87
Net increase in cash, cash equivalents and restricted cash	4	(3)
Cash, cash equivalents and restricted cash at beginning of period	14	17
Cash, cash equivalents and restricted cash at end of period	18	14
Significant non-cash transactions:
Accrued capital expenditures	84	66
Duke Energy Indiana
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	112	99
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	153	133
Equity component of AFUDC	(5)	(6)
Deferred income taxes	(12)	16
Payments for asset retirement obligations	(10)	(12)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	1
Receivables	(9)	15
Receivables from affiliated companies		3
Inventory	38	(21)
Other current assets	(23)	25
Increase (decrease) in
Accounts payable	1	(13)
Accounts payable to affiliated companies	(16)	(21)
Taxes accrued	71	43
Other current liabilities	20	(27)
Other assets	3	(4)
Other liabilities	12	8
Net cash provided by operating activities	336	238
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(186)	(210)
Purchases of debt and equity securities	(5)	(5)
Proceeds from sales and maturities of debt and equity securities	4	2
Notes receivable from affiliated companies	(1)	(543)
Other	(7)	(6)
Net cash used in investing activities	(195)	(762)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt		544
Notes payable to affiliated companies	(131)	(30)
Net cash provided by financing activities	(131)	514
Net increase in cash, cash equivalents and restricted cash	10	(10)
Cash, cash equivalents and restricted cash at beginning of period	7	25
Cash, cash equivalents and restricted cash at end of period	17	15
Significant non-cash transactions:
Accrued capital expenditures	74	70
Piedmont
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	203	178
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	48	46
Equity in losses (earnings) of unconsolidated affiliates	(2)	(2)
Equity component of AFUDC	(6)	(5)
Deferred income taxes	(12)	12
(Increase) decrease in
Receivables	(8)	65
Receivables from affiliated companies		(3)
Inventory	31	33
Other current assets	66	(9)
Increase (decrease) in
Accounts payable	(63)	(76)
Accounts payable to affiliated companies	(21)	9
Taxes accrued	45	12
Other current liabilities	(16)	(12)
Other assets	2	1
Other liabilities	(2)	(19)
Net cash provided by operating activities	265	230
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(200)	(231)
Notes receivable from affiliated companies	(198)
Other	(8)	(5)
Net cash used in investing activities	(406)	(236)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	347
Notes payable to affiliated companies	(530)	10
Capital contributions from parent	325
Net cash provided by financing activities	142	10
Net increase in cash, cash equivalents and restricted cash	1	4
Cash, cash equivalents and restricted cash at end of period	1	4
Significant non-cash transactions:
Accrued capital expenditures	$ 106	$ 114

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Changes in Equity - USD ($) shares in Millions, $ in Millions	Total		Preferred Stock	Common Stockholders' Equity		Additional Paid-in Capital		Retained Earnings		Accumulated Other Comprehensive (Loss) Income, Net (Losses) Gains on Cash Flow Hedges	Accumulated Other Comprehensive (Loss) Income, Net Unrealized (Losses) Gains on Available-for-Sale-Securities	Accumulated Other Comprehensive (Loss) Income, Pension and OPEB Adjustments	Noncontrolling Interests		Duke Energy Carolinas		Duke Energy CarolinasMember's Equity		Duke Energy CarolinasAccumulated Other Comprehensive (Loss) Income, Net (Losses) Gains on Cash Flow Hedges	Progress Energy	Progress EnergyCommon Stockholders' Equity	Progress EnergyAdditional Paid-in Capital	Progress EnergyRetained Earnings	Progress EnergyAccumulated Other Comprehensive (Loss) Income, Net (Losses) Gains on Cash Flow Hedges	Progress EnergyAccumulated Other Comprehensive (Loss) Income, Net Unrealized (Losses) Gains on Available-for-Sale-Securities	Progress EnergyAccumulated Other Comprehensive (Loss) Income, Pension and OPEB Adjustments	Progress EnergyNoncontrolling Interests	Duke Energy Progress	Duke Energy ProgressMember's Equity	Duke Energy Florida	Duke Energy FloridaMember's Equity	Duke Energy FloridaAccumulated Other Comprehensive (Loss) Income, Net Unrealized (Losses) Gains on Available-for-Sale-Securities	Duke Energy Ohio	Duke Energy OhioCommon Stock	Duke Energy OhioAdditional Paid-in Capital	Duke Energy OhioRetained Earnings	Duke Energy Indiana	Duke Energy IndianaMember's Equity	Piedmont	PiedmontCommon Stock	PiedmontRetained Earnings	Common Stock	Common StockCommon Stockholders' Equity	Common StockCommon Stock	Common StockAdditional Paid-in Capital
Beginning Balance at Dec. 31, 2019	$ 47,951		$ 1,962	$ 46,822		$ 40,881		$ 4,108		$ (51)	$ 3	$ (82)	$ 1,129							$ 15,593	$ 15,590	$ 9,143	$ 6,465	$ (10)	$ (1)	$ (7)	$ 3																	$ 1
Beginning Balance, in shares at Dec. 31, 2019																																												733
Beginning Balance (member's equity) at Dec. 31, 2019															$ 12,811		$ 12,818		$ (7)										$ 9,246	$ 6,788	$ 6,789	$ (1)						$ 4,575
Beginning Balance (parent) at Dec. 31, 2019																																	$ 3,683	$ 762	$ 2,776	$ 145			$ 2,443	$ 1,310	$ 1,133
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	851			899				899					(48)
Net income	938														339		339											$ 204	204	120	120		65			65	$ 99	99	178		178
Net income	890																			283	283		283
Other comprehensive (loss) income	(77)	[1]		(63)						(65)	1	1	(14)							2	2			1	1					1		1
Common stock issuances, including dividend reinvestment and employee benefits																																										$ 50	$ 50		$ 50
Common stock issuances, including dividend reinvestment and employee benefits (in shares)																																												2
Common stock dividends	(695)			(695)				(695)							(300)		(300)
Contributions from noncontrolling interests, net of transaction costs	103												103
Distributions to noncontrolling interest in subsidiaries	(7)												(7)
Other	(93)	[2]		(92)	[2]	(1)	[2]	(91)	[2]				(1)	[2]	(13)	[3]	(13)	[3]		(1)	(1)		(1)																(1)		(1)
Ending Balance at Mar. 31, 2020	48,083		1,962	46,921		40,930		4,221		(116)	4	(81)	1,162							15,877	15,874	9,143	6,747	(9)		(7)	3																	$ 1
Ending Balance (member's equity) at Mar. 31, 2020															12,837		12,844		(7)										9,450	6,909	6,909							4,674
Ending Balance, in shares at Mar. 31, 2020																																												735
Ending Balance (parent) at Mar. 31, 2020																																	$ 3,748	762	2,776	210			$ 2,620	1,310	1,310
Beginning Balance at Dec. 31, 2020	$ 49,184		1,962	47,964		43,767		2,471		(167)	6	(76)	1,220							16,241	16,237	9,143	7,109	(5)	(2)	(8)	4																	$ 1
Beginning Balance, in shares at Dec. 31, 2020	769																																90						100					769
Beginning Balance (member's equity) at Dec. 31, 2020															13,154		13,161		(7)									9,260	9,260	7,558	7,560	(2)					4,783	4,783
Beginning Balance (parent) at Dec. 31, 2020	$ 47,964																			16,237													$ 3,935	762	2,776	397			$ 2,715	1,310	1,405
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	902			953				953					(51)
Net income	992														312		312											210	210	117	117		$ 91			91	112	112	203		203
Net income	941																			290	290		290
Other comprehensive (loss) income	26	[1]		19						25	(8)	2	7											1	(1)					(1)		(1)
Common stock issuances, including dividend reinvestment and employee benefits																																										$ (3)	$ (3)		$ (3)
Common stock dividends	(744)			(744)				(744)
Contributions from noncontrolling interests, net of transaction costs	300			(3)		(3)							303
Distributions to noncontrolling interest in subsidiaries	(7)												(7)							(1)							(1)
Other																					1		1				(1)											1
Contribution from parent																																							$ 325	325
Ending Balance at Mar. 31, 2021	$ 49,658		$ 1,962	$ 48,186		$ 43,761		$ 2,680		$ (142)	$ (2)	$ (74)	$ 1,472							16,530	$ 16,528	$ 9,143	$ 7,400	$ (4)	$ (3)	$ (8)	$ 2																	$ 1
Ending Balance (member's equity) at Mar. 31, 2021															$ 13,466		$ 13,473		$ (7)									$ 9,470	$ 9,470	$ 7,674	$ 7,677	$ (3)					$ 4,896	$ 4,896
Ending Balance, in shares at Mar. 31, 2021	769																																90						100					769
Ending Balance (parent) at Mar. 31, 2021	$ 48,186																			$ 16,528													$ 4,026	$ 762	$ 2,776	$ 488			$ 3,243	$ 1,635	$ 1,608

[1]	Net of income tax impacts of approximately $8 million and $23 million for the three months ended March 31, 2021, and 2020, respectively.
[2]	Amounts in Retained earnings primarily represent impacts due to implementation of a new accounting standard related to Current Estimated Credit Losses. See Note 1 for additional discussion.
[3]	Amounts primarily represent impacts due to implementation of a new accounting standard related to Current Estimated Credit Losses. See Note 1 for additional discussion.

Organization and Basis of Prese

Organization and Basis of Presentation	3 Months Ended
Organization and Basis of Presentation	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	Index to Combined Notes to Condensed Consolidated Financial Statements The unaudited notes to the Condensed Consolidated Financial Statements that follow are a combined presentation. The following list indicates the registrants to which the footnotes apply. Applicable Notes Registrant 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Duke Energy • • • • • • • • • • • • • • • Duke Energy Carolinas • • • • • • • • • • • • • • Progress Energy • • • • • • • • • • • • • • • Duke Energy Progress • • • • • • • • • • • • • • Duke Energy Florida • • • • • • • • • • • • • • Duke Energy Ohio • • • • • • • • • • • • • • Duke Energy Indiana • • • • • • • • • • • • • • Piedmont • • • • • • • • • • • • • Tables within the notes may not sum across due to (i) Progress Energy's consolidation of Duke Energy Progress, Duke Energy Florida and other subsidiaries that are not registrants and (ii) subsidiaries that are not registrants but included in the consolidated Duke Energy balances. BASIS OF PRESENTATION These Condensed Consolidated Financial Statements have been prepared in accordance with GAAP for interim financial information and with the instructions to Form 10-Q and Regulation S-X. Accordingly, these Condensed Consolidated Financial Statements do not include all information and notes required by GAAP for annual financial statements and should be read in conjunction with the Consolidated Financial Statements in the Duke Energy Registrants’ combined Annual Report on Form 10-K for the year ended December 31, 2020. The information in these combined notes relates to each of the Duke Energy Registrants as noted in the Index to Combined Notes to Condensed Consolidated Financial Statements. However, none of the registrants make any representations as to information related solely to Duke Energy or the subsidiaries of Duke Energy other than itself. These Condensed Consolidated Financial Statements, in the opinion of the respective companies’ management, reflect all normal recurring adjustments necessary to fairly present the financial position and results of operations of each of the Duke Energy Registrants. Amounts reported in Duke Energy’s interim Condensed Consolidated Statements of Operations and each of the Subsidiary Registrants’ interim Condensed Consolidated Statements of Operations and Comprehensive Income are not necessarily indicative of amounts expected for the respective annual periods due to effects of seasonal temperature variations on energy consumption, regulatory rulings, timing of maintenance on electric generating units, changes in mark-to-market valuations, changing commodity prices and other factors. In preparing financial statements that conform to GAAP, management must make estimates and assumptions that affect the reported amounts of assets and liabilities, the reported amounts of revenues and expenses and the disclosure of contingent assets and liabilities at the date of the financial statements. Actual results could differ from those estimates. BASIS OF CONSOLIDATION These Condensed Consolidated Financial Statements include, after eliminating intercompany transactions and balances, the accounts of the Duke Energy Registrants and subsidiaries or VIEs where the respective Duke Energy Registrants have control. See Note 11 for additional information on VIEs. These Condensed Consolidated Financial Statements also reflect the Duke Energy Registrants’ proportionate share of certain jointly owned generation and transmission facilities. OTHER CURRENT LIABILITIES Included in Other within Current Liabilities on the Duke Energy Condensed Consolidated Balance Sheet is a current liability of $46 million and $936 million as of March 31, 2021, and December 31, 2020, respectively. The current liability, initially recorded in 2020, primarily represented Duke Energy's share of ACP's obligations of outstanding debt and to satisfy ARO requirements to restore construction sites. See Notes 3 and 11 for further information. NONCONTROLLING INTEREST Duke Energy maintains a controlling financial interest in certain less than wholly owned nonregulated subsidiaries. As a result, Duke Energy consolidates these subsidiaries and presents the third-party investors' portion of Duke Energy's net income (loss), net assets and comprehensive income (loss) as noncontrolling interest. Noncontrolling interest is included as a component of equity on the Condensed Consolidated Balance Sheet. Several operating agreements of Duke Energy's subsidiaries with noncontrolling interest are subject to allocations of earnings, tax attributes and cash flows in accordance with contractual agreements that vary throughout the lives of the subsidiaries. Therefore, Duke Energy and the other investors' (the owners) interests in the subsidiaries are not fixed, and the subsidiaries apply the Hypothetical Liquidation at Book Value (HLBV) method in allocating income or loss and other comprehensive income or loss (all measured on a pretax basis) to the owners. The HLBV method measures the amounts that each owner would hypothetically claim at each balance sheet reporting date, including tax benefits realized by the owners over the IRS recapture period, upon a hypothetical liquidation of the subsidiary at the net book value of its underlying assets. The change in the amount that each owner would hypothetically receive at the reporting date compared to the amount it would have received on the previous reporting date represents the amount of income or loss allocated to each owner for the reporting period. Other operating agreements of Duke Energy's subsidiaries with noncontrolling interest allocate profit and loss based on their pro rata shares of the ownership interest in the respective subsidiary. Therefore, Duke Energy allocates net income or loss and other comprehensive income or loss of these subsidiaries to the owners based on their pro rata shares . The following table presents cash received for the sale of noncontrolling interest and allocated losses to noncontrolling interest for the three months ended March 31, 2021, and 2020. Three Months Ended March 31, (in millions) 2021 2020 Noncontrolling Interest Capital Contributions Cash received for the sale of noncontrolling interest to tax equity members $ 303 $ 103 Cash received for the sale of noncontrolling interest to pro rata share members — — Total Noncontrolling Interest Capital Contributions 303 103 Noncontrolling Interest Allocation of Income Allocated losses to noncontrolling tax equity members utilizing the HLBV method 43 49 Allocated losses (gains) to noncontrolling members based on pro rata shares of ownership 8 (1) Total Noncontrolling Interest Allocated Losses $ 51 $ 48 CASH, CASH EQUIVALENTS AND RESTRICTED CASH Duke Energy, Progress Energy and Duke Energy Florida have restricted cash balances related primarily to collateral assets, escrow deposits and VIEs. See Notes 9 and 11 for additional information. Restricted cash amounts are included in Other within Current Assets and Other Noncurrent Assets on the Condensed Consolidated Balance Sheets. The following table presents the components of cash, cash equivalents and restricted cash included in the Condensed Consolidated Balance Sheets. March 31, 2021 December 31, 2020 Duke Duke Duke Progress Energy Duke Progress Energy Energy Energy Florida Energy Energy Florida Current Assets Cash and cash equivalents $ 379 $ 74 $ 22 $ 259 $ 59 $ 11 Other 210 13 13 194 39 39 Other Noncurrent Assets Other 103 102 — 103 102 — Total cash, cash equivalents and restricted cash $ 692 $ 189 $ 35 $ 556 $ 200 $ 50 INVENTORY Provisions for inventory write-offs were not material at March 31, 2021, and December 31, 2020. The components of inventory are presented in the tables below. March 31, 2021 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Materials and supplies $ 2,365 $ 816 $ 1,011 $ 680 $ 332 $ 77 $ 313 $ 11 Coal 464 170 160 101 59 12 122 — Natural gas, oil and other fuel 247 35 165 101 64 19 1 26 Total inventory $ 3,076 $ 1,021 $ 1,336 $ 882 $ 455 $ 108 $ 436 $ 37 December 31, 2020 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Materials and supplies $ 2,312 $ 785 $ 999 $ 673 $ 325 $ 78 $ 307 $ 12 Coal 561 186 193 131 63 16 165 — Natural gas, oil and other fuel 294 39 183 107 76 16 1 56 Total inventory $ 3,167 $ 1,010 $ 1,375 $ 911 $ 464 $ 110 $ 473 $ 68 NEW ACCOUNTING STANDARDS No new accounting standards were adopted by the Duke Energy Registrants in 2021, but the following accounting standard was adopted by the Duke Energy Registrants in 2020. Current Expected Credit Losses. In June 2016, the Financial Accounting Standards Board (FASB) issued new accounting guidance for credit losses. Duke Energy adopted the new accounting guidance for credit losses effective January 1, 2020, using the modified retrospective method of adoption, which does not require restatement of prior year results. Duke Energy did not adopt any practical expedients. Duke Energy recognizes allowances for credit losses based on management's estimate of losses expected to be incurred over the lives of certain assets or guarantees. Management monitors credit quality, changes in expected credit losses and the appropriateness of the allowance for credit losses on a forward-looking basis. Management reviews the risk of loss periodically as part of the existing assessment of collectability of receivables. Duke Energy reviews the credit quality of its counterparties as part of its regular risk management process and requires credit enhancements, such as deposits or letters of credit, as appropriate and as allowed by regulators. Duke Energy recorded cumulative effects of changes in accounting principles related to the adoption of new credit loss standard, for allowances for credit losses of trade and other receivables, insurance receivables and financial guarantees. These amounts are included in the Condensed Consolidated Balance Sheets in Receivables, Receivables of VIEs, Other Noncurrent Assets and Other Noncurrent Liabilities. See Notes 4 and 12 for more information. Duke Energy recorded an adjustment for the cumulative effect of a change in accounting principle due to the adoption of this standard on January 1, 2020, as shown in the table below: January 1, 2020 Duke Duke Duke Duke Energy Progress Energy Energy (in millions) Energy Carolinas Energy Progress Florida Piedmont Total pretax impact to Retained Earnings $ 120 $ 16 $ 2 $ 1 $ 1 $ 1 The following new accounting standard has been issued but not yet adopted by the Duke Energy Registrants as of March 31, 2021. Reference Rate Reform. In March 2020, the FASB issued new accounting guidance for reference rate reform. This guidance is elective and provides expedients to facilitate financial reporting for the anticipated transition away from the London Inter-bank Offered Rate (LIBOR) and other interbank reference rates by the end of 2021. The optional expedients are effective for modification of existing contracts or new arrangements executed between March 12, 2020, through December 31, 2022. Duke Energy has variable-rate debt and manages interest rate risk by entering into financial contracts including interest rate swaps that are generally indexed to LIBOR. Impacted financial arrangements extending beyond 2021 may require contractual amendment or termination to fully adapt to a post-LIBOR environment. Duke Energy is assessing these financial arrangements and is evaluating the use of optional expedients outlined in the new accounting guidance. Alternative index provisions are also being assessed and incorporated into new financial arrangements that extend beyond 2021. The full outcome of the transition away from LIBOR cannot be determined at this time, but is not expected to have a material impact on the financial statements.

Business Segments

Business Segments	3 Months Ended
Business Segments	Mar. 31, 2021
Segment Reporting [Abstract]
Business Segments	BUSINESS SEGMENTS Duke Energy Duke Energy's segment structure includes the following segments: Electric Utilities and Infrastructure, Gas Utilities and Infrastructure and Commercial Renewables. The Electric Utilities and Infrastructure segment primarily includes Duke Energy's regulated electric utilities in the Carolinas, Florida and the Midwest. The Gas Utilities and Infrastructure segment includes Piedmont, Duke Energy's natural gas local distribution companies in Ohio and Kentucky, and Duke Energy's natural gas storage and midstream pipeline investments. The Commercial Renewables segment is primarily comprised of nonregulated utility-scale wind and solar generation assets located throughout the U.S. In 2021, Duke Energy continues to monitor recoverability of its renewable merchant plants located in the Electric Reliability Council of Texas West market and in the PJM West market due to declining market pricing and declining long-term forecasted energy prices, primarily driven by lower forecasted natural gas prices. The assets were not impaired as of March 31, 2021, because the carrying value of approximately $210 million continues to approximate the aggregate estimated future undiscounted cash flows. A continued decline in energy market pricing would likely result in a future impairment. Duke Energy retained 51% ownership interest in these facilities following the 2019 transaction to sell a minority interest in certain renewable assets. The remainder of Duke Energy’s operations is presented as Other, which is primarily comprised of interest expense on holding company debt, unallocated corporate costs, Duke Energy’s wholly owned captive insurance company, Bison, and Duke Energy's ownership interest in National Methanol Company. Business segment information is presented in the following tables. Segment assets presented exclude intercompany assets. Three Months Ended March 31, 2021 Electric Gas Total Utilities and Utilities and Commercial Reportable (in millions) Infrastructure Infrastructure Renewables Segments Other Eliminations Total Unaffiliated revenues $ 5,273 $ 752 $ 119 $ 6,144 $ 6 $ — $ 6,150 Intersegment revenues 8 23 — 31 20 (51) — Total revenues $ 5,281 $ 775 $ 119 $ 6,175 $ 26 $ (51) $ 6,150 Segment income (loss) (a) $ 820 $ 245 $ 27 $ 1,092 $ (139) $ — $ 953 Less: Noncontrolling interests 51 Add: Preferred stock dividend 39 Net Income $ 941 Segment assets $ 138,734 $ 14,139 $ 6,894 $ 159,767 $ 3,710 $ (12) $ 163,465 Three Months Ended March 31, 2020 Electric Gas Total Utilities and Utilities and Commercial Reportable (in millions) Infrastructure Infrastructure Renewables Segments Other Eliminations Total Unaffiliated revenues $ 5,174 $ 640 $ 129 $ 5,943 $ 6 $ — $ 5,949 Intersegment revenues 9 24 — 33 17 (50) — Total revenues $ 5,183 $ 664 $ 129 $ 5,976 $ 23 $ (50) $ 5,949 Segment income (loss) (b) $ 705 $ 249 $ 57 $ 1,011 $ (112) $ — $ 899 Less: Noncontrolling interests 48 Add: Preferred stock dividend 39 Net Income $ 890 (a) Commercial Renewables includes a $35 million loss related to Texas Storm Uri, of which $8 million is recorded within Nonregulated electric and other revenues, $2 million within Operations, maintenance and other, $29 million within Equity in (losses) earnings of unconsolidated affiliates and $12 million within Loss Attributable to Noncontrolling Interests on the Condensed Consolidated Statements of Operations. See Note 4 for additional information. G as Utilities and Infrastructure includes $6 million, recorded within Equity in (losses) earnings of unconsolidated affiliates on the Condensed Consolidated Statements of Operations, related to gas pipeline investments. See Note 3 for additional information. (b) Other includes a $98 million reversal, recorded within Operations, maintenance and other on the Condensed Consolidated Statements of Operations, related to 2018 severance costs due to the partial settlement of the Duke Energy Carolinas 2019 North Carolina rate case. See Note 3 for additional information. Duke Energy Ohio Duke Energy Ohio has two reportable segments, Electric Utilities and Infrastructure and Gas Utilities and Infrastructure. The remainder of Duke Energy Ohio's operations is presented as Other. Three Months Ended March 31, 2021 Electric Gas Total Utilities and Utilities and Reportable (in millions) Infrastructure Infrastructure Segments Other Eliminations Total Total revenues $ 363 $ 169 $ 532 $ — $ — $ 532 Segment income/Net income $ 50 $ 43 $ 93 $ (2) $ — $ 91 Segment assets $ 6,544 $ 3,575 $ 10,119 $ 29 $ (7) $ 10,141 Three Months Ended March 31, 2020 Electric Gas Total Utilities and Utilities and Reportable (in millions) Infrastructure Infrastructure Segments Other Total Total revenues $ 346 $ 152 $ 498 $ — $ 498 Segment income/Net income $ 30 $ 36 $ 66 $ (1) $ 65

Regulatory Matters

Regulatory Matters	3 Months Ended
Regulatory Matters	Mar. 31, 2021
Regulated Operations [Abstract]
Regulatory Matters	REGULATORY MATTERS RATE-RELATED INFORMATION The NCUC, PSCSC, FPSC, IURC, PUCO, TPUC and KPSC approve rates for retail electric and natural gas services within their states. The FERC approves rates for electric sales to wholesale customers served under cost-based rates (excluding Ohio and Indiana), as well as sales of transmission service. The FERC also regulates certification and siting of new interstate natural gas pipeline projects. Duke Energy Carolinas and Duke Energy Progress 2021 Coal Ash Settlement On January 22 , 2021, Duke Energy Carolinas and Duke Energy Progress entered into the Coal Combustion Residuals Settlement Agreement (the “CCR Settlement Agreement”) with the North Carolina Public Staff (Public Staff), the North Carolina Attorney General’s Office and the Sierra Club (collectively, the "Settling Parties"), which was filed with the NCUC on January 25, 2021. The CCR Settlement Agreement resolves all coal ash prudence and cost recovery issues in connection with 2019 rate cases filed by Duke Energy Carolinas and Duke Energy Progress with the NCUC, as well as the equitable sharing issue on remand from the 2017 Duke Energy Carolinas and Duke Energy Progress North Carolina rate cases as a result of the December 11, 2020, North Carolina Supreme Court opinion. The settlement also provides clarity on coal ash cost recovery in North Carolina for Duke Energy Carolinas and Duke Energy Progress through January 2030 and February 2030 (the "Term"), respectively. Duke Energy Carolinas and Duke Energy Progress agreed not to seek recovery of approximately $1 billion of systemwide deferred coal ash expenditures, but will retain the ability to earn a debt and equity return during the amortization period, which shall be five years in the pending 2019 North Carolina rate cases and will be set by the NCUC in future rate case proceedings. The equity return and the amortization period on deferred coal ash costs under the 2017 Duke Energy Carolinas and Duke Energy Progress North Carolina rate cases will remain unaffected. The equity return on deferred coal ash costs under the 2019 North Carolina rate cases and future rate cases in North Carolina will be set at 150 basis points lower than the authorized return on equity (ROE) then in effect, with a capital structure composed of 48% debt and 52% equity. Duke Energy Carolinas and Duke Energy Progress retain the ability to earn a full WACC return during the deferral period, which is the period from when costs are incurred until they are recovered in rates. The Settling Parties agreed that execution by Duke Energy Carolinas and Duke Energy Progress of a settlement agreement between themselves and the NCDEQ dated December 31, 2019, (the “DEQ Settlement”) and the coal ash management plans included therein or subsequently approved by DEQ are reasonable and prudent. The Settling Parties retain the right to challenge the reasonableness and prudence of actions taken by Duke Energy Carolinas and Duke Energy Progress and costs incurred to implement the scope of work agreed upon in the DEQ Settlement, after February 1, 2020, and March 1, 2020, for Duke Energy Carolinas and Duke Energy Progress, respectively. The Settling Parties further agreed to waive rights through the Term to challenge the reasonableness or prudence of Duke Energy Carolinas’ and Duke Energy Progress’ historical coal ash management practices, and to waive the right to assert any arguments that future coal ash costs, including financing costs, shall be shared between either company and customers through equitable sharing or any other rate base or return adjustment that shares the revenue requirement burden of coal ash costs not otherwise disallowed due to imprudence. The Settling Parties agreed to a sharing arrangement for future coal ash insurance litigation proceeds between Duke Energy Carolinas and Duke Energy Progress and North Carolina customers, if achieved. On January 29, 2021, Duke Energy Carolinas and Duke Energy Progress filed joint motions with the Settling Parties seeking approval of the CCR Settlement Agreement, along with supporting testimony and exhibits from Duke Energy Carolinas and Duke Energy Progress. On February 5, 2021, the Public Staff filed testimony and exhibits supporting the CCR Settlement Agreement. As a result of the CCR Settlement Agreement, Duke Energy Carolinas and Duke Energy Progress recorded a pretax charge of approximately $454 million and $494 million, respectively, in the fourth quarter of 2020 to Impairment charges and a reversal of approximately $50 million and $102 million, respectively, to Regulated electric operating revenues on the respective Consolidated Statements of Operations. The Coal Ash Settlement was approved without modification in the NCUC Orders in the 2019 rate cases on March 31, 2021, and April 16, 2021, for Duke Energy Carolinas and Duke Energy Progress, respectively. 2020 North Carolina Storm Securitization Filings On October 26, 2020, Duke Energy Carolinas and Duke Energy Progress filed a joint petition with the NCUC, as agreed to in partial settlements reached in the 2019 North Carolina Rate Cases for Duke Energy Carolinas and Duke Energy Progress, seeking authorization for the financing of the costs of each utility's storm recovery activities required as a result of Hurricane Florence, Hurricane Michael, Hurricane Dorian and Winter Storm Diego. Specifically, Duke Energy Carolinas and Duke Energy Progress requested that the NCUC find that their storm recovery costs and related financing costs are appropriately financed by debt secured by storm recovery property, and that the commission issue financing orders by which each utility may accomplish such financing using a securitization structure. On January 27, 2021, Duke Energy Carolinas, Duke Energy Progress and the Public Staff filed an Agreement and Stipulation of Partial Settlement, which is subject to review and approval of the NCUC, resolving certain accounting issues, including agreement to support an 18- to 20-year bond period. The total revenue requirement over a proposed 20-year bond period for the storm recovery charges is approximately $287 million for Duke Energy Carolinas and $920 million for Duke Energy Progress. A remote evidentiary hearing ended on January 29, 2021, and on February 1, 2021, the NCUC granted a motion by Duke Energy Carolinas and Duke Energy Progress for a temporary 30-day waiver of the 135-day time frame for the NCUC to issue orders on the joint petition, extending the deadline for the NCUC to issue an order to May 10, 2021. In the NCUC Orders in the 2019 rate cases on March 31, 2021, and April 16, 2021, for Duke Energy Carolinas and Duke Energy Progress, respectively, the reasonableness and prudence of the deferred storm costs was approved. Duke Energy Carolinas and Duke Energy Progress cannot predict the outcome of this matter. COVID-19 Filings North Carolina Duke Energy Carolinas and Duke Energy Progress filed a joint petition on August 7, 2020, with the NCUC for deferral treatment of incremental costs and waived customer fees due to the COVID-19 pandemic. Comments on the joint petition were filed on November 5, 2020, and reply comments were filed on November 30, 2020. Duke Energy Carolinas and Duke Energy Progress cannot predict the outcome of this matter. South Carolina Duke Energy Carolinas and Duke Energy Progress filed a report on June 30, 2020, as required by PSCSC order, reporting revenue impact, costs and savings related to COVID-19 to date. On August 14, 2020, Duke Energy Carolinas and Duke Energy Progress filed a joint petition with the PSCSC for approval of an accounting order to defer incremental COVID-19 related costs incurred through June 30, 2020, and for the ongoing months during the duration of the COVID-19 pandemic. The deferral request did not include lost revenues. Updates on cost impacts were filed on September 30, 2020, and included financial impacts through the end of August 2020. On October 16, 2020, the South Carolina Office of Regulatory Staff (ORS) requested the PSCSC delay taking formal action on the deferral request until the ORS and any intervenors complete discovery. The PSCSC issued an order on October 21, 2020, to grant additional time to complete discovery until January 20, 2021, and to establish a procedural schedule. Updates on cost impacts were filed on December 30, 2020, and included financial impacts through November 30, 2020. On January 15, 2021, the ORS requested the PSCSC suspend the dates for the ORS report and public hearing. The ORS conferred with the companies regarding the status of the docket, and the parties mutually agreed that recently enacted federal laws addressing COVID-19 aid and recovery should be studied before further action is taken in this docket. On January 27, 2021, the PSCSC voted to grant the ORS request to suspend the virtual public hearing. The ORS filed its report on April 16, 2021. Duke Energy Carolinas and Duke Energy Progress cannot predict the outcome of this matter. Duke Energy Carolinas 2017 North Carolina Rate Case On August 25, 2017, Duke Energy Carolinas filed an application with the NCUC for a rate increase for retail customers of approximately $647 million. On February 28, 2018, Duke Energy Carolinas and the Public Staff filed an Agreement and Stipulation of Partial Settlement resolving certain portions of the proceeding. Terms of the settlement included an ROE of 9.9% and a capital structure of 52% equity and 48% debt. On June 22, 2018, the NCUC issued an order approving the Stipulation of Partial Settlement and requiring a revenue reduction. The North Carolina Attorney General and other parties separately filed Notices of Appeal to the North Carolina Supreme Court. The North Carolina Supreme Court consolidated the Duke Energy Carolinas and Duke Energy Progress appeals. On December 11, 2020, the North Carolina Supreme Court issued an opinion, which affirmed, in part, and reversed and remanded, in part, the NCUC’s decisions. In the Opinion, the court upheld the NCUC's decision to include coal ash costs in the cost of service, as well as the NCUC’s discretion to allow a return on the unamortized balance of coal ash costs. The court also remanded to the NCUC a single issue to consider the assessment of support for the Public Staff’s equitable sharing argument. In response to a NCUC order seeking comments on the proposed procedure on remand, on January 11, 2021, Duke Energy Carolinas, Duke Energy Progress, the Public Staff, the North Carolina Attorney General, Sierra Club and Carolina Industrial Group for Fair Utility Rates II and III filed joint comments proposing that the NCUC not hold additional evidentiary hearings, but instead rely upon existing records in the 2017 North Carolina rate cases, or in the alternative the records in the 2019 North Carolina rate cases, in deciding the issue on remand. On January 22, 2021, Duke Energy Carolinas and Duke Energy Progress entered into the CCR Settlement Agreement with the Settling Parties, which was filed with the NCUC on January 25, 2021, and approved by the NCUC on March 31, 2021. 2019 North Carolina Rate Case On September 30, 2019, Duke Energy Carolinas filed an application with the NCUC for a net rate increase for retail customers of approximately $291 million, which represented an approximate 6% increase in annual base revenues. The gross rate case revenue increase request was $445 million, which was offset by an EDIT rider of $154 million to return to customers North Carolina and federal EDIT resulting from recent reductions in corporate tax rates. The request for a rate increase was driven by major capital investments subsequent to the previous base rate case, coal ash pond closure costs, accelerated coal plant depreciation and deferred 2018 storm costs. Duke Energy Carolinas requested rates be effective no later than August 1, 2020. The NCUC established a procedural schedule with an evidentiary hearing to begin on March 23, 2020. On March 16, 2020, in consideration of public health and safety as a result of the COVID-19 pandemic, Duke Energy Carolinas filed a motion with the NCUC seeking a suspension of the procedural schedule in the rate case, including issuing discovery requests, and postponement of the evidentiary hearing for 60 days. Also on March 16, 2020, the NCUC issued an Order Postponing Hearing and Addressing Procedural Matters, which postponed the evidentiary hearing until further order by the commission. On March 25, 2020, Duke Energy Carolinas and the Public Staff filed an Agreement and Stipulation of Partial Settlement, subject to review and approval of the NCUC, resolving certain issues in the base rate proceeding. On July 24, 2020, Duke Energy Carolinas filed its request for approval of its notice to customers required to implement temporary rates. On July 27, 2020, Duke Energy Carolinas filed a joint motion with Duke Energy Progress and the Public Staff notifying the commission that the parties reached a joint partial settlement with the Public Staff. Also on July 27, 2020, Duke Energy Carolinas filed a letter stating that it intended to update its temporary rates calculation to reflect the terms of the partial settlement. On July 31, 2020, Duke Energy Carolinas and the Public Staff filed a Second Agreement and Stipulation of Partial Settlement (Second Partial Settlement), subject to review and approval of the NCUC, resolving certain remaining issues in the base rate proceeding. The remaining items litigated at hearing included recovery of deferred coal ash compliance costs that are subject to asset retirement obligation accounting, implementation of new depreciation rates and the amortization period of the loss on the hydro station sale. On August 4, 2020, Duke Energy Carolinas filed an amended motion for approval of its amended notice to customers, seeking to exercise its statutory right to implement temporary rates subject to refund on or after August 24, 2020. The revenue requirement to be recovered, subject to refund, through the temporary rates was based on and consistent with the base rate component of the Second Partial Settlement and excluded the items to be litigated noted above. The NCUC approved the August 4, 2020 amended temporary rates motion on August 6, 2020, and temporary rates went into effect on August 24, 2020. The Duke Energy Carolinas evidentiary hearing concluded on September 18, 2020, and post-hearing filings were made with the NCUC from all parties by November 4, 2020. On January 22, 2021, Duke Energy Carolinas and Duke Energy Progress entered into the CCR Settlement Agreement with the Settling Parties, which was filed with the NCUC on January 25, 2021. On March 31, 2021, the NCUC issued an order approving the March 25, 2020, and July 31, 2020, partial settlements. The order includes approval of 1) an ROE of 9.6% based upon a capital structure of 52% equity and 48% debt; 2) deferral treatment of approximately $800 million of grid improvement projects with a return; 3) a flow back period of five years for unprotected federal EDIT; and 4) the reasonableness and prudence of $213 million of deferred storm costs, which were removed from the rate case and for which Duke Energy Carolinas filed a petition seeking securitization in October 2020. Additionally, the order approved without modification the CCR Settlement Agreement. The order denied Duke Energy Carolinas' proposal to shorten the remaining depreciable lives of certain Duke Energy Carolinas coal-fired generating units, indicating the appropriate proceeding for the review of generating plant retirements is Duke Energy Carolinas' integrated resource planning (IRP) proceeding. On April 12, 2021, Duke Energy Carolinas filed its final revenue requirement with the NCUC, which results in a net increase of approximately $33 million. Revised customer rates are expected to become effective in June 2021. 2018 South Carolina Rate Case On November 8, 2018, Duke Energy Carolinas filed an application with the PSCSC for a rate increase for retail customers of approximately $168 million. After hearings in March 2019, the PSCSC issued an order on May 21, 2019, which included an ROE of 9.5% and a capital structure of 53% equity and 47% debt. The order also included the following material components: • Approval of cancellation of the Lee Nuclear Project, with Duke Energy Carolinas maintaining the Combined Operating License; • Approval of recovery of $125 million (South Carolina retail portion) of Lee Nuclear Project development costs (including AFUDC through December 2017) over a 12-year period, but denial of a return on the deferred balance of costs; • Approval of recovery of $96 million of coal ash costs over a five-year period with a return at Duke Energy Carolinas' WACC; • Denial of recovery of $115 million of certain coal ash costs deemed to be related to the Coal Ash Act and incremental to the federal CCR rule; • Approval of a $66 million decrease to base rates to reflect the change in ongoing tax expense, primarily the reduction in the federal income tax rate from 35% to 21%; • Approval of a $45 million decrease through the EDIT Rider to return EDIT resulting from the federal tax rate change and deferred revenues since January 2018 related to the change, to be returned in accordance with the Average Rate Assumption Method (ARAM) for protected EDIT, over a 20-year period for unprotected EDIT associated with Property, Plant and Equipment, over a five-year period for unprotected EDIT not associated with Property, Plant and Equipment and over a five-year period for the deferred revenues; and • Approval of a $17 million decrease through the EDIT Rider related to reductions in the North Carolina state income tax rate from 6.9% to 2.5% to be returned over a five-year period. As a result of the order, revised customer rates were effective June 1, 2019. On May 31, 2019, Duke Energy Carolinas filed a Petition for Rehearing or Reconsideration of that order contending substantial rights of Duke Energy Carolinas were prejudiced by unlawful, arbitrary and capricious rulings by the PSCSC on certain issues presented in the proceeding. On June 19, 2019, the PSCSC issued a Directive denying Duke Energy Carolinas' request to rehear or reconsider the commission's rulings on certain issues presented in the proceeding including coal ash remediation and disposal costs, ROE and the recovery of a return on deferred operation and maintenance expenses. An order detailing the commission's decision in the Directive was issued on October 18, 2019. Duke Energy Carolinas filed a notice of appeal on November 15, 2019, with the Supreme Court of South Carolina. On November 20, 2019, the South Carolina Energy Users Committee filed a Notice of Appeal with the Supreme Court of South Carolina. Initial briefs were filed on April 21, 2020, which included the South Carolina Energy User's Committee brief arguing that the PSCSC erred in allowing Duke Energy Carolinas' recovery of costs related to the Lee Nuclear Station. Response briefs were filed on July 6, 2020, and reply briefs were filed on August 11, 2020. Oral arguments before the Supreme Court of South Carolina have been scheduled to occur on May 26, 2021. Based on legal analysis and the filing of the appeal, Duke Energy Carolinas has not recorded an adjustment for its deferred coal ash costs in this matter. Duke Energy Carolinas cannot predict the outcome of this matter. Duke Energy Progress 2017 North Carolina Rate Case On June 1, 2017, Duke Energy Progress filed an application with the NCUC for a rate increase for retail customers of approximately $477 million, which was subsequently adjusted to $420 million. On November 22, 2017, Duke Energy Progress and the Public Staff filed an Agreement and Stipulation of Partial Settlement resolving certain portions of the proceeding. Terms of the settlement included an ROE of 9.9% and a capital structure of 52% equity and 48% debt. On February 23, 2018, the NCUC issued an order approving the stipulation. The Public Staff, the North Carolina Attorney General and the Sierra Club filed notices of appeal to the North Carolina Supreme Court. The North Carolina Supreme Court consolidated the Duke Energy Carolinas and Duke Energy Progress appeals. On December 11, 2020, the North Carolina Supreme Court issued an opinion, which affirmed, in part, and reversed and remanded, in part, the NCUC’s decisions. In the Opinion, the court upheld the NCUC's decision to include coal ash costs in the cost of service, as well as the NCUC’s discretion to allow a return on the unamortized balance of coal ash costs. The court also remanded to the NCUC a single issue to consider the assessment of support for the Public Staff’s equitable sharing argument. In response to a NCUC order seeking comments on the proposed procedure on remand, on January 11, 2021, Duke Energy Carolinas, Duke Energy Progress, the Public Staff, the North Carolina Attorney General, Sierra Club and Carolina Industrial Group for Fair Utility Rates II and III filed joint comments proposing that the NCUC not hold additional evidentiary hearings, but instead rely upon existing records in the 2017 North Carolina rate cases or in the alternative the records in the 2019 North Carolina rate cases, in deciding the issue on remand. On January 22, 2021, Duke Energy Progress and Duke Energy Carolinas entered into the CCR Settlement Agreement with the Settling Parties, which was filed with the NCUC on January 25, 2021, and approved by the NCUC on April 16, 2021. 2019 North Carolina Rate Case On October 30, 2019, Duke Energy Progress filed an application with the NCUC for a net rate increase for retail customers of approximately $464 million, which represented an approximate 12.3% increase in annual base revenues. The gross rate case revenue increase request was $586 million, which was offset by riders of $122 million, primarily an EDIT rider of $120 million to return to customers North Carolina and federal EDIT resulting from recent reductions in corporate tax rates. The request for rate increase was driven by major capital investments subsequent to the previous base rate case, coal ash pond closure costs, accelerated coal plant depreciation and deferred 2018 storm costs. Duke Energy Progress sought to defer and recover incremental Hurricane Dorian storm costs in this proceeding and requested rates be effective no later than September 1, 2020. As a result of the COVID-19 pandemic, on March 24, 2020, the NCUC suspended the procedural schedule and postponed the previously scheduled evidentiary hearing on this matter indefinitely. On April 7, 2020, the NCUC issued an order partially resuming the procedural schedule requiring intervenors to file direct testimony on April 13, 2020. Public Staff filed supplemental direct testimony on April 23, 2020. Duke Energy Progress filed rebuttal testimony on May 4, 2020. On June 2, 2020, Duke Energy Progress and the Public Staff filed an Agreement and Stipulation of Partial Settlement, subject to review and approval of the NCUC, resolving certain issues in the base rate proceeding. On July 27, 2020, Duke Energy Progress filed a joint motion with Duke Energy Carolinas and the Public Staff notifying the commission that the parties reached a joint partial settlement with the Public Staff. On July 31, 2020, Duke Energy Progress and the Public Staff filed a Second Agreement and Stipulation of Partial Settlement, subject to review and approval of the NCUC, resolving certain remaining issues in the base rate proceeding. The remaining items litigated at hearing included recovery of deferred coal ash compliance costs that are subject to asset retirement obligation accounting and implementation of new depreciation rates. On August 7, 2020, Duke Energy Progress filed a motion for approval of notice required to implement temporary rates, seeking to exercise its statutory right to implement temporary rates subject to refund on or after September 1, 2020. The revenue requirement to be recovered subject to refund through the temporary rates was based on and consistent with the terms of the base rate component of the settlement agreements with the Public Staff and excluded items to be litigated noted above. Duke Energy Progress will not begin the amortization or implementation of these items until a final determination is issued in the rate case and new base rates are implemented. These items will also be excluded when determining whether a refund of amounts collected through these temporary rates is needed. In addition, Duke Energy Progress also sought authorization to place a temporary decrement EDIT Rider into effect, concurrent with the temporary base rate change. The temporary rate changes are not final rates and remain subject to the NCUC's determination of the just and reasonable rates to be charged by Duke Energy Progress on a permanent basis. The NCUC approved the August 7, 2020 temporary rates motion on August 11, 2020, and temporary rates went into effect on September 1, 2020. The Duke Energy Progress evidentiary hearing concluded on October 6, 2020, and post-hearing filings were filed with the NCUC from all parties by December 4, 2020. On January 22, 2021, Duke Energy Progress and Duke Energy Carolinas entered into the CCR Settlement Agreement with the Settling Parties, which was filed with the NCUC on January 25, 2021. On April 16, 2021, the NCUC issued an order approving the June 2, 2020, and July 31, 2020, partial settlements. The order includes approval of 1) an ROE of 9.6% based upon a capital structure of 52% equity and 48% debt; 2) deferral treatment of approximately $400 million of grid improvement projects with a return; 3) a flow back period of five years for unprotected federal EDIT; and 4) the reasonableness and prudence of approximately $714 million of deferred storm costs, which were removed from the rate case and for which Duke Energy Progress filed a petition seeking securitization in October 2020. Additionally, the order approved without modification the CCR Settlement Agreement. The order denied Duke Energy Progress' proposal to shorten the remaining depreciable lives of certain Duke Energy Progress coal-fired generating units, indicating the appropriate proceeding for the review of generating plant retirements is Duke Energy Progress' IRP proceeding. On April 26, 2021, Duke Energy Progress filed its final revenue requirement with the NCUC, which results in a net increase of approximately $178 million. Revised customer rates are expected to become effective in June 2021. Hurricane Dorian Hurricane Dorian reached the Carolinas in September 2019 as a Category 2 hurricane making landfall within Duke Energy Progress’ service territory. Total estimated incremental operation and maintenance expenses incurred to repair and restore the system are approximately $168 million with an additional $4 million in capital investments made for restoration efforts. Approximately $145 million of the operation and maintenance expenses are deferred in Regulatory assets within Other Noncurrent Assets on the Condensed Consolidated Balance Sheets as of March 31, 2021, and December 31, 2020. A request for an accounting order to defer incremental storm costs associated with Hurricane Dorian was included in Duke Energy Progress' October 30, 2019, general rate case filing with the NCUC. Terms of the June 2, 2020, Agreement and Stipulation of Partial Settlement removed incremental storm costs from the general rate case. A petition seeking to securitize these costs, along with costs from Hurricane Florence, Hurricane Michael and Winter Storm Diego, was filed on October 26, 2020, with the NCUC. For information on the securitization filing, see "2020 North Carolina Storm Securitization Filings." Duke Energy Progress cannot predict the outcome of this matter. 2018 South Carolina Rate Case On November 8, 2018, Duke Energy Progress filed an application with the PSCSC for a rate increase for retail customers of approximately $59 million. After hearings in April 2019, the PSCSC issued an order on May 21, 2019, which included an ROE of 9.5% and a capital structure of 53% equity and 47% debt. The order also included the following material components: • Approval of recovery of $4 million of coal ash costs over a five-year period with a return at Duke Energy Progress' WACC; • Denial of recovery of $65 million of certain coal ash costs deemed to be related to the Coal Ash Act and incremental to the federal CCR rule; • Approval of a $17 million decrease to base rates to reflect the change in ongoing tax expense, primarily the reduction in the federal income tax rate from 35% to 21%; • Approval of a $12 million decrease through the EDIT Tax Savings Rider resulting from the federal tax rate change and deferred revenues since January 2018 related to the change, to be returned in accordance with ARAM for protected EDIT, over a 20-year period for unprotected EDIT associated with Property, Plant and Equipment, over a five-year period for unprotected EDIT not associated with Property, Plant and Equipment and over a three-year period for the deferred revenues; and • Approval of a $12 million increase due to the expiration of EDIT related to reductions in the North Carolina state income tax rate from 6.9% to 2.5%. As a result of the order, revised customer rates were effective June 1, 2019. On May 31, 2019, Duke Energy Progress filed a Petition for Rehearing or Reconsideration of that order contending substantial rights of Duke Energy Progress were prejudiced by unlawful, arbitrary and capricious rulings by the PSCSC on certain issues presented in the proceeding. On June 19, 2019, the PSCSC issued a Directive denying Duke Energy Progress' request to rehear or reconsider the commission's rulings on certain issues presented in the proceeding including coal ash remediation and disposal costs, ROE and the recovery of a return on deferred operation and maintenance expenses, but allowing additional litigation-related costs. As a result of the Directive allowing litigation-related costs, customer rates were revised effective July 1, 2019. An order detailing the commission's decision in the Directive was issued on October 18, 2019. Duke Energy Progress filed a notice of appeal on November 15, 2019, with the Supreme Court of South Carolina. Initial briefs were filed on April 21, 2020. Response briefs were filed on July 6, 2020, and reply briefs were filed on August 11, 2020. Oral arguments before the Supreme Court of South Carolina have been scheduled to occur on May 26, 2021. Based on legal analysis and the filing of the appeal, Duke Energy Progress has not recorded an adjustment for its deferred coal ash costs in this matter. Duke Energy Progress cannot predict the outcome of this matter. Western Carolinas Modernization Plan On October 8, 2018, Duke Energy Progress filed an application with the NCUC for a CPCN to construct the Hot Springs Microgrid Solar and Battery Storage Facility, which was approved with certain conditions on May 10, 2019. A hearing to update the NCUC on the status of the project was held on March 5, 2020. Construction began in May 2020 with commercial operation expected to begin in October 2021. On July 27, 2020, Duke Energy Progress filed an application with the NCUC for a CPCN to construct the Woodfin Solar Facility, a 5-MW solar generating facility to be constructed on a closed landfill in Buncombe County. The expert hearing was held on November 18, 2020. The application was approved and a CPCN was granted by order of the NCUC on April 20, 2021. FERC Return on Equity Complaints On October 11, 2019, North Carolina Eastern Municipal Power Agency (NCEMPA) filed a complaint at the FERC against Duke Energy Progress pursuant to Section 206 of the Federal Power Act (FPA), alleging that the 11% stated ROE component contained in the demand formula rate in the Full Requirements Power Purchase Agreement (FRPPA) between NCEMPA and Duke Energy Progress is unjust and unreasonable. On July 16, 2020, the FERC set this matter for hearing and settlement judge procedures and established a refund effective date of October 11, 2019. In its order setting the matter for settlement, the FERC allowed for the consideration of variations to the base transmission-related ROE methodology developed in its Order No. 569-A, through the introduction of “specific facts and circumstances” involving issues specific to the case. The parties reached a settlement in principle at a settlement conference on January 7, 2021, and filed a settlement package on March 10, 2021. The FERC Trial Staff filed comments in support of the se

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
Commitments and Contingencies	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	COMMITMENTS AND CONTINGENCIES ENVIRONMENTAL The Duke Energy Registrants are subject to federal, state and local regulations regarding air and water quality, hazardous and solid waste disposal, coal ash and other environmental matters. These regulations can be changed from time to time, imposing new obligations on the Duke Energy Registrants. The following environmental matters impact all Duke Energy Registrants. Remediation Activities In addition to AROs recorded as a result of various environmental regulations, the Duke Energy Registrants are responsible for environmental remediation at various sites. These include certain properties that are part of ongoing operations and sites formerly owned or used by Duke Energy entities. These sites are in various stages of investigation, remediation and monitoring. Managed in conjunction with relevant federal, state and local agencies, remediation activities vary based upon site conditions and location, remediation requirements, complexity and sharing of responsibility. If remediation activities involve joint and several liability provisions, strict liability, or cost recovery or contribution actions, the Duke Energy Registrants could potentially be held responsible for environmental impacts caused by other potentially responsible parties and may also benefit from insurance policies or contractual indemnities that cover some or all cleanup costs. Liabilities are recorded when losses become probable and are reasonably estimable. The total costs that may be incurred cannot be estimated because the extent of environmental impact, allocation among potentially responsible parties, remediation alternatives and/or regulatory decisions have not yet been determined at all sites. Additional costs associated with remediation activities are likely to be incurred in the future and could be significant. Costs are typically expensed as Operation, maintenance and other on the Condensed Consolidated Statements of Operations unless regulatory recovery of the costs is deemed probable. The following table contains information regarding reserves for probable and estimable costs related to the various environmental sites. These reserves are recorded in Accounts Payable within Current Liabilities and Other within Other Noncurrent Liabilities on the Condensed Consolidated Balance Sheets. (in millions) March 31, 2021 December 31, 2020 Reserves for Environmental Remediation Duke Energy $ 74 $ 75 Duke Energy Carolinas 18 19 Progress Energy 18 19 Duke Energy Progress 6 6 Duke Energy Florida 12 12 Duke Energy Ohio 21 22 Duke Energy Indiana 5 6 Piedmont 11 10 Additional losses in excess of recorded reserves that could be incurred for the stages of investigation, remediation and monitoring for environmental sites that have been evaluated at this time are not material except as presented in the table below. (in millions) Duke Energy $ 20 Duke Energy Carolinas 12 Duke Energy Ohio 4 LITIGATION Duke Energy Texas Storm Uri Tort Litigation Duke Energy and several Duke Energy renewables project companies have been named in multiple lawsuits arising out of Texas Storm Uri in mid-February 2021, and particularly, in the deregulated market managed by the Electric Reliability Council of Texas.. Currently, 15 state court actions have been filed in counties across Texas and one case is pending in federal court in Texas. These lawsuits, filed by individuals, seek recovery for property damages, personal injury and for wrongful death allegedly incurred by the plaintiffs as a result of power losses, which the plaintiffs claim was the result of the defendants' failure to take appropriate precautions. Certain defendants have moved to transfer all related cases including those naming Duke Energy entities into a Texas state court multi-district litigation proceeding for coordination before a single judge. No ruling has yet been issued on this motion. Duke Energy cannot predict the outcomes of these state and federal litigation matters. Duke Energy Carolinas and Duke Energy Progress Coal Ash Insurance Coverage Litigation In March 2017, Duke Energy Carolinas and Duke Energy Progress filed a civil action in the North Carolina Business Court against various insurance providers. The lawsuit seeks payment for coal ash-related liabilities covered by third-party liability insurance policies. The insurance policies were issued between 1971 and 1986 and provide third-party liability insurance for property damage. The civil action seeks damages for breach of contract and indemnification for costs arising from the Coal Ash Act and the U.S. Environmental Protection Agency CCR rule at 15 coal-fired plants in North Carolina and South Carolina. Fact discovery has been completed. The parties' fully briefed and argued motions relating to key legal matters are pending before the court for rulings. Trial remains scheduled for January 24, 2022. Duke Energy Carolinas and Duke Energy Progress cannot predict the outcome of this matter. Duke Energy Carolinas NTE Carolinas II, LLC Litigation In November 2017, Duke Energy Carolinas entered into a standard FERC large generator interconnection agreement (LGIA) with NTE Carolinas II, LLC (NTE), a company that proposed to build a combined-cycle natural gas plant in Rockingham County, North Carolina. On September 6, 2019, Duke Energy Carolinas filed a lawsuit in Mecklenburg County Superior Court against NTE for breach of contract, alleging that NTE's failure to pay benchmark payments for Duke Energy Carolinas' transmission system upgrades required under the interconnection agreement constituted a termination of the interconnection agreement. Duke Energy Carolinas is seeking a monetary judgment against NTE because NTE failed to make multiple milestone payments. The lawsuit was moved to federal court in North Carolina. NTE filed a motion to dismiss Duke Energy Carolinas’ complaint and brought counterclaims alleging anti-competitive conduct and violations of state and federal statutes. Duke Energy Carolinas filed a motion to dismiss NTE's counterclaims. On May 21, 2020, in response to a NTE petition challenging Duke Energy Carolinas' termination of the LGIA, FERC issued a ruling (i) that it has exclusive jurisdiction to determine whether a transmission provider may terminate a LGIA, (ii) FERC approval is required to terminate a conforming LGIA if objected to by the interconnection customer, and (iii) Duke Energy may not announce the termination of a conforming LGIA unless FERC has approved the termination. FERC's Office of Enforcement also initiated an investigation of Duke Energy Carolinas into matters pertaining to the LGIA. Duke Energy Carolinas is cooperating with the Office of Enforcement but cannot predict the outcome of this investigation. On August 17, 2020, the court denied both NTE’s and Duke Energy Carolinas’ Motion to Dismiss. The parties are in active discovery and trial is scheduled for June 20, 2022. Duke Energy Carolinas cannot predict the outcome of this matter. Asbestos-related Injuries and Damages Claims Duke Energy Carolinas has experienced numerous claims for indemnification and medical cost reimbursement related to asbestos exposure. These claims relate to damages for bodily injuries alleged to have arisen from exposure to or use of asbestos in connection with construction and maintenance activities conducted on its electric generation plants prior to 1985. As of March 31, 2021, there were 126 asserted claims for non-malignant cases with cumulative relief sought of up to $31 million, and 47 asserted claims for malignant cases with cumulative relief sought of up to $17 million. Based on Duke Energy Carolinas’ experience, it is expected that the ultimate resolution of most of these claims likely will be less than the amount claimed. Duke Energy Caroli nas has recognized asbestos-related reserves of $564 million at March 31, 2021, and $572 million at December 31, 2020. These reserves are classified in Other within Other Noncurrent Liabilities and Other within Current Liabilities on the Condensed Consolidated Balance Sheets. These reserves are based upon Duke Energy Carolinas' best estimate for current and future asbestos claims through 2040 and are recorded on an undiscounted basis. In light of the uncertainties inherent in a longer-term forecast, management does not believe they can reasonably estimate the indemnity and medical costs that might be incurred after 2040 related to such potential claims. It is possible Duke Energy Carolinas may incur asbestos liabilities in excess of the recorded reserves. Duke Energy Carolinas has third-party insurance to cover certain losses related to asbestos-related injuries and damages above an aggregate self-insured retention. Duke Energy Carolinas’ cumulative payments began to exceed the self-insured retention in 2008. Future payments up to the policy limit will be reimbursed by the third-party insurance carrier. The insurance policy limit for potential future insurance recoveries indemnification and medical cost claim payments is $714 million in excess of the self-insured retention. Receivables for insurance recoveries were $704 million at March 31, 2021, and December 31, 2020. These amounts are classified in Other within Other Noncurrent Assets and Receivables within Current Assets on the Condensed Consolidated Balance Sheets. Duke Energy Carolinas is not aware of any uncertainties regarding the legal sufficiency of insurance claims. Duke Energy Carolinas believes the insurance recovery asset is probable of recovery as the insurance carrier continues to have a strong financial strength rating. As described in Note 1, Duke Energy adopted the new guidance for credit losses effective January 1, 2020, using the modified retrospective method of adoption, which does not require restatement of prior year reported results. The reserve for credit losses for insurance receivables based on adoption of the new standard is $15 million for Duke Energy and Duke Energy Carolinas as of March 31, 2021, and December 31, 2020. The insurance receivable is evaluated based on the risk of default and the historical losses, current conditions and expected conditions around collectability. Management evaluates the risk of default annually based on payment history, credit rating and changes in the risk of default from credit agencies. Duke Energy Progress and Duke Energy Florida Spent Nuclear Fuel Matters On June 18, 2018, Duke Energy Progress and Duke Energy Florida sued the U.S. in the U.S. Court of Federal Claims for damages incurred for the period 2014 through 2018. The lawsuit claimed the Department of Energy breached a contract in failing to accept spent nuclear fuel under the Nuclear Waste Policy Act of 1982 and asserted damages for the cost of on-site storage in the amount of $100 million and $200 million for Duke Energy Progress and Duke Energy Florida, respectively. Discovery is ongoing and a trial is expected to occur in 2021. Duke Energy Florida Power Purchase Dispute Arbitration Duke Energy Florida, on behalf of its customers, entered into a PPA for the purchase of firm capacity and energy from a qualifying facility under the Public Utilities Regulatory Policies Act of 1978. Duke Energy Florida determined the qualifying facility did not perform in accordance with the PPA, and Duke Energy Florida terminated the PPA. The qualifying facility counterparty filed a confidential American Arbitration Association (AAA) arbitration demand, challenging the termination of the PPA and seeking damages. The final arbitration hearing occurred during the week of December 7, 202 0. An arbitral award was issued in March 2021, upholding Duke Energy Florida's positions on all issues and awarding the company termination costs. Duke Energy Indiana Coal Ash Basin Closure Plan Appeal On January 27, 2020, Hoosier Environmental Council (HEC) filed a Petition for Administrative Review with the Indiana Office of Environmental Adjudication challenging the Indiana Department of Environmental Management’s December 10, 2019, partial approval of Duke Energy Indiana’s ash pond closure plan. On March 11, 2020, Duke Energy Indiana filed a Motion to Dismiss. On May 5, 2020, the court denied the motion. After hearing oral arguments in early April 2021 on Duke Energy Indiana's and HEC's competing Motions for Summary Judgment, on May 4, 2021, the administrative court rejected all of HEC’s claims and issued a ruling in favor of Duke Energy Indiana. HEC has until June 3, 2021, to seek judicial review of the order . Du ke Energy Indiana cannot predict the outcome of this matter. Other Litigation and Legal Proceedings The Duke Energy Registrants are involved in other legal, tax and regulatory proceedings arising in the ordinary course of business, some of which involve significant amounts. The Duke Energy Registrants believe the final disposition of these proceedings will not have a material effect on their results of operations, cash flows or financial position. The table below presents recorded reserves based on management’s best estimate of probable loss for legal matters, excluding asbestos-related reserves discussed above. Reserves are classified on the Condensed Consolidated Balance Sheets in Other within Other Noncurrent Liabilities and Other within Current Liabilities. The reasonably possible range of loss in excess of recorded reserves is not material, other than as described above. (in millions) March 31, 2021 December 31, 2020 Reserves for Legal Matters Duke Energy $ 65 $ 68 Duke Energy Carolinas 3 2 Progress Energy 57 61 Duke Energy Progress 11 13 Duke Energy Florida 26 28 Piedmont 1 1 OTHER COMMITMENTS AND CONTINGENCIES General As part of their normal business, the Duke Energy Registrants are party to various financial guarantees, performance guarantees and other contractual commitments to extend guarantees of credit and other assistance to various subsidiaries, investees and other third parties. These guarantees involve elements of performance and credit risk, which are not fully recognized on the Condensed Consolidated Balance Sheets and have uncapped maximum potential payments. However, the Duke Energy Registrants do not believe these guarantees will have a material effect on their results of operations, cash flows or financial position.

Debt and Credit Facilities

Debt and Credit Facilities	3 Months Ended
Debt and Credit Facilities	Mar. 31, 2021
Debt Disclosure [Abstract]
Debt And Credit Facilities	DEBT AND CREDIT FACILITIES SUMMARY OF SIGNIFICANT DEBT ISSUANCES The following table summarizes significant debt issuances (in millions). Three Months Ended March 31, 2021 Duke Duke Duke Duke Duke Duke Maturity Interest Duke Energy Energy Energy Energy Energy Energy Issuance Date Date Rate Energy (Parent) Carolinas Progress Florida Ohio Indiana Piedmont Unsecured Debt March 2021 (a) Mar 2031 2.500 % $ 350 $ — $ — $ — $ — $ — $ — $ 350 Total issuances $ 350 $ — $ — $ — $ — $ — $ — $ 350 (a) Debt issued to repay at maturity $160 million senior unsecured notes due June 2021, pay down short-term debt and for general corporate purposes. In March 2021, Duke Energy Carolinas priced $1 billion of First Mortgage Bonds. The issuance and sale of securities settled in April 2021, in two separate tranches. The first tranche was issued for $550 million at a fixed interest rate of 2.55% and mature in April 2031. The second tranche was issued for $450 million at a fixed interest rate of 3.45% and mature in April 2051. Proceeds from the issuance will be used to repay at maturity $500 million of 3.90% First Mortgage Bonds due June 2021, pay down intercompany short-term debt and for general company purposes. CURRENT MATURITIES OF LONG-TERM DEBT The following table shows the significant components of Current maturities of long-term debt on the Condensed Consolidated Balance Sheets. The Duke Energy Registrants currently anticipate satisfying these obligations with cash on hand and proceeds from additional borrowings. (in millions) Maturity Date Interest Rate March 31, 2021 Unsecured Debt Duke Energy (Parent) May 2021 0.698 % (a) 500 Piedmont June 2021 4.240 % 160 Duke Energy (Parent) September 2021 3.550 % 500 Duke Energy (Parent) September 2021 1.800 % 750 Duke Energy Florida November 2021 0.441 % (a) 200 Duke Energy Progress February 2022 0.369 % (a) 700 Duke Energy (Parent) March 2022 3.227 % 300 Duke Energy (Parent) March 2022 0.827 % (a) 300 First Mortgage Bonds Duke Energy Carolinas June 2021 3.900 % 500 Duke Energy Florida August 2021 3.100 % 300 Duke Energy Progress September 2021 3.000 % 500 Duke Energy Progress September 2021 8.625 % 100 Duke Energy Indiana January 2022 8.850 % 53 Other (b) 723 Current maturities of long-term debt $ 5,586 (a) Debt has a floating interest rate. (b) Includes finance lease obligations, amortizing debt, tax-exempt bonds with mandatory put options and small bullet maturities. AVAILABLE CREDIT FACILITIES Master Credit Facility In March 2021, Duke Energy amended its existing $8 billion Master Credit Facility to extend the termination date to March 2026. The Duke Energy Registrants, excluding Progress Energy, have borrowing capacity under the Master Credit Facility up to a specified sublimit for each borrower. Duke Energy has the unilateral ability at any time to increase or decrease the borrowing sublimits of each borrower, subject to a maximum sublimit for each borrower. The amount available under the Master Credit Facility has been reduced to backstop issuances of commercial paper, certain letters of credit and variable-rate demand tax-exempt bonds that may be put to the Duke Energy Registrants at the option of the holder. The table below includes the current borrowing sublimits and available capacity under these credit facilities. March 31, 2021 Duke Duke Duke Duke Duke Duke Duke Energy Energy Energy Energy Energy Energy (in millions) Energy (Parent) Carolinas Progress Florida Ohio Indiana Piedmont Facility size (a) $ 8,000 $ 2,650 $ 1,475 $ 1,250 $ 700 $ 625 $ 600 $ 700 Reduction to backstop issuances Commercial paper (b) (3,466) (1,781) (741) (292) (243) (259) (150) — Outstanding letters of credit (31) (25) (4) (2) — — — — Tax-exempt bonds (81) — — — — — (81) — Available capacity under the Master Credit Facility $ 4,422 $ 844 $ 730 $ 956 $ 457 $ 366 $ 369 $ 700 (a) Represents the sublimit of each borrower. (b) Duke Energy issued $625 million of commercial paper and loaned the proceeds through the money pool to Duke Energy Carolinas, Duke Energy Progress, Duke Energy Ohio and Duke Energy Indiana. The balances are classified as Long-Term Debt Payable to Affiliated Companies on the Condensed Consolidated Balance Sheets. Other Credit Facilities March 31, 2021 (in millions) Facility size Amount drawn Duke Energy (Parent) Three (a) $ 1,000 $ 500

Goodwill

Goodwill	3 Months Ended
Goodwill	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	GOODWILL Duke Energy The following table presents the goodwill by reportable segment included on Duke Energy's Condensed Consolidated Balance Sheets at March 31, 2021, and December 31, 2020. Electric Utilities Gas Utilities Commercial (in millions) and Infrastructure and Infrastructure Renewables Total Goodwill balance $ 17,379 $ 1,924 $ 122 $ 19,425 Accumulated impairment charges — — (122) (122) Goodwill, adjusted for accumulated impairment charges $ 17,379 $ 1,924 $ — $ 19,303 Duke Energy Ohio Duke Energy Ohio's Goodwill balance of $920 million, allocated $596 million to Electric Utilities and Infrastructure and $324 million to Gas Utilities and Infrastructure, is presented net of accumulated impairment charges of $216 million on the Condensed Consolidated Balance Sheets at March 31, 2021, and December 31, 2020. Progress Energy Progress Energy's Goodwill is included in the Electric Utilities and Infrastructure segment and there are no accumulated impairment charges. Piedmont Piedmont's Goodwill is included in the Gas Utilities and Infrastructure segment and there are no accumulated impairment charges.

Related Party Transactions

Related Party Transactions	3 Months Ended
Related Party Transactions	Mar. 31, 2021
Related Party Transactions [Abstract]
Related Party Transactions	RELATED PARTY TRANSACTIONS The Subsidiary Registrants engage in related party transactions in accordance with applicable state and federal commission regulations. Refer to the Condensed Consolidated Balance Sheets of the Subsidiary Registrants for balances due to or due from related parties. Material amounts related to transactions with related parties included on the Condensed Consolidated Statements of Operations and Comprehensive Income are presented in the following table. Three Months Ended March 31, (in millions) 2021 2020 Duke Energy Carolinas Corporate governance and shared service expenses (a) $ 203 $ 134 Indemnification coverages (b) 6 5 Joint Dispatch Agreement (JDA) revenue (c) 13 7 JDA expense (c) 40 24 Intercompany natural gas purchases (d) 14 6 Progress Energy Corporate governance and shared service expenses (a) $ 181 $ 146 Indemnification coverages (b) 10 9 JDA revenue (c) 40 24 JDA expense (c) 13 7 Intercompany natural gas purchases (d) 19 19 Duke Energy Progress Corporate governance and shared service expenses (a) $ 105 $ 75 Indemnification coverages (b) 5 4 JDA revenue (c) 40 24 JDA expense (c) 13 7 Intercompany natural gas purchases (d) 19 19 Duke Energy Florida Corporate governance and shared service expenses (a) $ 76 $ 71 Indemnification coverages (b) 5 5 Duke Energy Ohio Corporate governance and shared service expenses (a) $ 79 $ 84 Indemnification coverages (b) 1 1 Duke Energy Indiana Corporate governance and shared service expenses (a) $ 113 $ 106 Indemnification coverages (b) 2 2 Piedmont Corporate governance and shared service expenses (a) $ 33 $ 34 Indemnification coverages (b) 1 1 Intercompany natural gas sales (d) 33 25 Natural gas storage and transportation costs (e) 6 6 (a) The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, primarily related to human resources, employee benefits, information technology, legal and accounting fees, as well as other third-party costs. These amounts are primarily recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income. (b) The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income. (c) Duke Energy Carolinas and Duke Energy Progress participate in a JDA, which allows the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power and expenses from the purchase of power pursuant to the JDA are recorded in Operating Revenues and Fuel used in electric generation and purchased power, respectively, on the Condensed Consolidated Statements of Operations and Comprehensive Income. (d) Piedmont provides long-term natural gas delivery service to certain Duke Energy Carolinas and Duke Energy Progress natural gas-fired generation facilities. Piedmont records the sales in Operating revenues, and Duke Energy Carolinas and Duke Energy Progress record the related purchases as a component of Fuel used in electric generation and purchased power on their respective Condensed Consolidated Statements of Operations and Comprehensive Income. (e) Piedmont has related party transactions as a customer of its equity method investments in Pine Needle LNG Company, LLC, Hardy Storage Company, LLC and Cardinal Pipeline Company, LLC natural gas storage and transportation facilities. These expenses are included in Cost of natural gas on Piedmont's Condensed Consolidated Statements of Operations and Comprehensive Income. In addition to the amounts presented above, the Subsidiary Registrants have other affiliate transactions, including rental of office space, participation in a money pool arrangement, other operational transactions, such as pipeline lease arrangements, and their proportionate share of certain charged expenses. These transactions of the Subsidiary Registrants are incurred in the ordinary course of business and are eliminated in consolidation. As discussed in Note 11, certain trade receivables have been sold by Duke Energy Ohio and Duke Energy Indiana to CRC, an affiliate formed by a subsidiary of Duke Energy. The proceeds obtained from the sales of receivables are largely cash but do include a subordinated note from CRC for a portion of the purchase price. Intercompany Income Taxes Duke Energy and the Subsidiary Registrants file a consolidated federal income tax return and other state and jurisdictional returns. The Subsidiary Registrants have a tax sharing agreement with Duke Energy for the allocation of consolidated tax liabilities and benefits. Income taxes recorded represent amounts the Subsidiary Registrants would incur as separate C-Corporations. The following table includes the balance of intercompany income tax receivables and payables for the Subsidiary Registrants. Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Carolinas Energy Progress Florida Ohio Indiana Piedmont March 31, 2021 Intercompany income tax receivable $ — $ 84 $ — $ 46 $ — $ — $ — Intercompany income tax payable 31 — 12 — 2 36 39 December 31, 2020 Intercompany income tax receivable $ — $ — $ — $ — $ — $ 9 $ 10 Intercompany income tax payable 31 33 46 35 2 — —

Derivatives and Hedging

Derivatives and Hedging	3 Months Ended
Derivatives and Hedging	Mar. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging	DERIVATIVES AND HEDGING The Duke Energy Registrants use commodity and interest rate contracts to manage commodity price risk and interest rate risk. The primary use of commodity derivatives is to hedge the generation portfolio against changes in the prices of electricity and natural gas. Piedmont enters into natural gas supply contracts to provide diversification, reliability and natural gas cost benefits to its customers. Interest rate derivatives are used to manage interest rate risk associated with borrowings. All derivative instruments not identified as NPNS are recorded at fair value as assets or liabilities on the Condensed Consolidated Balance Sheets. Cash collateral related to derivative instruments executed under master netting arrangements is offset against the collateralized derivatives on the Condensed Consolidated Balance Sheets. The cash impacts of settled derivatives are recorded as operating activities on the Condensed Consolidated Statements of Cash Flows. INTEREST RATE RISK The Duke Energy Registrants are exposed to changes in interest rates as a result of their issuance or anticipated issuance of variable-rate and fixed-rate debt and commercial paper. Interest rate risk is managed by limiting variable-rate exposures to a percentage of total debt and by monitoring changes in interest rates. To manage risk associated with changes in interest rates, the Duke Energy Registrants may enter into interest rate swaps, U.S. Treasury lock agreements and other financial contracts. In anticipation of certain fixed-rate debt issuances, a series of forward-starting interest rate swaps or Treasury locks may be executed to lock in components of current market interest rates. These instruments are later terminated prior to or upon the issuance of the corresponding debt. Cash Flow Hedges For a derivative designated as hedging the exposure to variable cash flows of a future transaction, referred to as a cash flow hedge, the effective portion of the derivative's gain or loss is initially reported as a component of other comprehensive income and subsequently reclassified into earnings once the future transaction impacts earnings. Amounts for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt. Gains and losses reclassified out of accumulated other comprehensive loss for the three months ended March 31, 2021, and 2020, were not material. Duke Energy's interest rate derivatives designated as hedges include interest rate swaps used to hedge existing debt within the Commercial Renewables segment and forward-starting interest rate swaps not accounted for under regulatory accounting. Undesignated Contracts Undesignated contracts primarily include contracts not designated as a hedge because they are accounted for under regulatory accounting or contracts that do not qualify for hedge accounting. Duke Energy’s interest rate swaps for its regulated operations employ regulatory accounting. With regulatory accounting, the mark-to-market gains or losses on the swaps are deferred as regulatory liabilities or regulatory assets, respectively. Regulatory assets and liabilities are amortized consistent with the treatment of the related costs in the ratemaking process. The accrual of interest on the swaps is recorded as Interest Expense on the Duke Energy Registrant's Condensed Consolidated Statements of Operations and Comprehensive Income. The following table shows notional amounts of outstanding derivatives related to interest rate risk. March 31, 2021 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Cash flow hedges $ 1,630 $ — $ — $ — $ — $ — Undesignated contracts 1,731 400 1,250 750 500 27 Total notional amount (a) $ 3,361 $ 400 $ 1,250 $ 750 $ 500 $ 27 December 31, 2020 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Cash flow hedges $ 632 $ — $ — $ — $ — $ — Undesignated contracts 1,177 400 750 750 — 27 Total notional amount (a) $ 1,809 $ 400 $ 750 $ 750 $ — $ 27 (a) Duke Energy includes amounts related to consolidated VIEs of $631 million in cash flow hedges and $54 million in undesignated contracts as of March 31, 2021, and $632 million in cash flow hedges as of December 31, 2020. COMMODITY PRICE RISK The Duke Energy Registrants are exposed to the impact of changes in the prices of electricity purchased and sold in bulk power markets and natural gas purchases, including Piedmont's natural gas supply contracts. Exposure to commodity price risk is influenced by a number of factors including the term of contracts, the liquidity of markets and delivery locations. To manage risk associated with commodity prices, the Duke Energy Registrants may enter into long-term power purchase or sales contracts and long-term natural gas supply agreements. Cash Flow Hedges For derivatives designated as hedging the exposure to variable cash flows of a future transaction, referred to as a cash flow hedge, the derivative's gain or loss is initially reported as a component of other comprehensive income and subsequently reclassified into earnings once the future transaction impacts earnings. Gains and losses reclassified out of accumulated other comprehensive loss for the three months ended March 31, 2021, and 2020, were not material. Duke Energy’s commodity derivatives designated as hedges include long-term electricity sales in the Commercial Renewables segment. Undesignated Contracts For the Subsidiary Registrants, bulk power electricity and natural gas purchases flow through fuel adjustment clauses, formula-based contracts or other cost-sharing mechanisms. Differences between the costs included in rates and the incurred costs, including undesignated derivative contracts, are largely deferred as regulatory assets or regulatory liabilities. Piedmont policies allow for the use of financial instruments to hedge commodity price risks. The strategy and objective of these hedging programs are to use the financial instruments to reduce natural gas costs volatility for customers. Volumes The tables below include volumes of outstanding commodity derivatives. Amounts disclosed represent the absolute value of notional volumes of commodity contracts excluding NPNS. The Duke Energy Registrants have netted contractual amounts where offsetting purchase and sale contracts exist with identical delivery locations and times of delivery. Where all commodity positions are perfectly offset, no quantities are shown. March 31, 2021 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy Carolinas Energy Progress Ohio Indiana Piedmont Electricity (GWh) (a) 16,259 — — — 1,325 4,214 — Natural gas (millions of dekatherms) 675 151 158 158 — 2 364 December 31, 2020 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy Carolinas Energy Progress Ohio Indiana Piedmont Electricity (GWh) (a) 35,409 — — — 2,559 10,802 — Natural gas (millions of dekatherms) 678 145 158 158 — 2 373 (a) Duke Energy includes 10,720 GWh and 22,048 GWh related to cash flow hedges as of March 31, 2021, and December 31, 2020, respectively. LOCATION AND FAIR VALUE OF DERIVATIVE ASSETS AND LIABILITIES RECOGNIZED ON THE CONDENSED CONSOLIDATED BALANCE SHEETS The following tables show the fair value and balance sheet location of derivative instruments. Although derivatives subject to master netting arrangements are netted on the Condensed Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown. Derivative Assets March 31, 2021 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Commodity Contracts Not Designated as Hedging Instruments Current $ 32 $ 17 $ 12 $ 12 $ — $ — $ 2 $ 1 Noncurrent 14 7 7 7 — — — — Total Derivative Assets – Commodity Contracts $ 46 $ 24 $ 19 $ 19 $ — $ — $ 2 $ 1 Interest Rate Contracts Designated as Hedging Instruments Current $ 31 $ — $ — $ — $ — $ — $ — $ — Not Designated as Hedging Instruments Current $ 129 $ 38 $ 84 $ 81 $ 3 $ — $ — $ — Total Derivative Assets – Interest Rate Contracts $ 160 $ 38 $ 84 $ 81 $ 3 $ — $ — $ — Total Derivative Assets $ 206 $ 62 $ 103 $ 100 $ 3 $ — $ 2 $ 1 Derivative Liabilities March 31, 2021 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Commodity Contracts Designated as Hedging Instruments Current $ 19 $ — $ — $ — $ — $ — $ — — Noncurrent 109 — — — — — — — Not Designated as Hedging Instruments Current $ 19 $ — $ — $ — $ — $ — $ — $ 19 Noncurrent 154 — 25 9 — — — 129 Total Derivative Liabilities – Commodity Contracts $ 301 $ — $ 25 $ 9 $ — $ — $ — $ 148 Interest Rate Contracts Designated as Hedging Instruments Current $ 15 $ — $ — $ — $ — $ — $ — $ — Noncurrent 25 — — — — — — — Not Designated as Hedging Instruments Current 4 — 3 — 3 1 — — Noncurrent 4 — — — — 4 — — Total Derivative Liabilities – Interest Rate Contracts $ 48 $ — $ 3 $ — $ 3 $ 5 $ — $ — Total Derivative Liabilities $ 349 $ — $ 28 $ 9 $ 3 $ 5 $ — $ 148 Derivative Assets December 31, 2020 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Commodity Contracts Not Designated as Hedging Instruments Current $ 30 $ 14 $ 9 $ 9 $ — $ 1 $ 6 $ 1 Noncurrent 13 6 6 6 — — — — Total Derivative Assets – Commodity Contracts $ 43 $ 20 $ 15 $ 15 $ — $ 1 $ 6 $ 1 Interest Rate Contracts Not Designated as Hedging Instruments Current $ 18 $ — $ 18 $ 18 $ — $ — $ — $ — Total Derivative Assets – Interest Rate Contracts $ 18 $ — $ 18 $ 18 $ — $ — $ — $ — Total Derivative Assets $ 61 $ 20 $ 33 $ 33 $ — $ 1 $ 6 $ 1 Derivative Liabilities December 31, 2020 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Commodity Contracts Designated as Hedging Instruments Current $ 14 $ — $ — $ — $ — $ — $ — $ — Noncurrent 70 — — — — — — — Not Designated as Hedging Instruments Current $ 30 $ 13 $ 2 $ 2 $ — $ — $ 1 $ 15 Noncurrent 137 3 27 12 — — — 107 Total Derivative Liabilities – Commodity Contracts $ 251 $ 16 $ 29 $ 14 $ — $ — $ 1 $ 122 Interest Rate Contracts Designated as Hedging Instruments Current $ 15 $ — $ — $ — $ — $ — $ — $ — Noncurrent 48 — — — — — — — Not Designated as Hedging Instruments Current 5 4 — — — 1 — — Noncurrent 5 — — — — 5 — — Total Derivative Liabilities – Interest Rate Contracts $ 73 $ 4 $ — $ — $ — $ 6 $ — $ — Total Derivative Liabilities $ 324 $ 20 $ 29 $ 14 $ — $ 6 $ 1 $ 122 OFFSETTING ASSETS AND LIABILITIES The following tables present the line items on the Condensed Consolidated Balance Sheets where derivatives are reported. Substantially all of Duke Energy's outstanding derivative contracts are subject to enforceable master netting arrangements. The gross amounts offset in the tables below show the effect of these netting arrangements on financial position, and include collateral posted to offset the net position. The amounts shown are calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below. Derivative Assets March 31, 2021 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Current Gross amounts recognized $ 192 $ 55 $ 96 $ 93 $ 3 $ — $ 2 $ 1 Gross amounts offset — — — — — — — — Net amounts presented in Current Assets: Other $ 192 $ 55 $ 96 $ 93 $ 3 $ — $ 2 $ 1 Noncurrent Gross amounts recognized $ 14 $ 7 $ 7 $ 7 $ — $ — $ — $ — Gross amounts offset (4) — (4) (4) — — — — Net amounts presented in Other Noncurrent Assets: Other $ 10 $ 7 $ 3 $ 3 $ — $ — $ — $ — Derivative Liabilities March 31, 2021 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Current Gross amounts recognized $ 57 $ — $ 3 $ — $ 3 $ 1 $ — $ 19 Gross amounts offset — — — — — — — — Net amounts presented in Current Liabilities: Other $ 57 $ — $ 3 $ — $ 3 $ 1 $ — $ 19 Noncurrent Gross amounts recognized $ 292 $ — $ 25 $ 9 $ — $ 4 $ — $ 129 Gross amounts offset (4) — (4) (4) — — — — Net amounts presented in Other Noncurrent Liabilities: Other $ 288 $ — $ 21 $ 5 $ — $ 4 $ — $ 129 Derivative Assets December 31, 2020 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Current Gross amounts recognized $ 48 $ 14 $ 27 $ 27 $ — $ 1 $ 6 $ 1 Gross amounts offset (3) (2) (2) (2) — — — — Net amounts presented in Current Assets: Other $ 45 $ 12 $ 25 $ 25 $ — $ 1 $ 6 $ 1 Noncurrent Gross amounts recognized $ 13 $ 6 $ 6 $ 6 $ — $ — $ — $ — Gross amounts offset (5) (1) (4) (4) — — — — Net amounts presented in Other Noncurrent Assets: Other $ 8 $ 5 $ 2 $ 2 $ — $ — $ — $ — Derivative Liabilities December 31, 2020 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Current Gross amounts recognized $ 64 $ 17 $ 2 $ 2 $ — $ 1 $ 1 $ 15 Gross amounts offset (3) (2) (2) (2) — — — — Net amounts presented in Current Liabilities: Other $ 61 $ 15 $ — $ — $ — $ 1 $ 1 $ 15 Noncurrent Gross amounts recognized $ 260 $ 3 $ 27 $ 12 $ — $ 5 $ — $ 107 Gross amounts offset (5) (1) (4) (4) — — — — Net amounts presented in Other Noncurrent Liabilities: Other $ 255 $ 2 $ 23 $ 8 $ — $ 5 $ — $ 107

Investments in Debt and Equity

Investments in Debt and Equity Securities	3 Months Ended
Investments in Debt and Equity Securities	Mar. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Investments In Debt And Equity Securities	INVESTMENTS IN DEBT AND EQUITY SECURITIES Duke Energy’s investments in debt and equity securities are primarily comprised of investments held in (i) the NDTF at Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida, (ii) the grantor trusts at Duke Energy Progress, Duke Energy Florida and Duke Energy Indiana related to OPEB plans and (iii) Bison. The Duke Energy Registrants classify investments in debt securities as AFS and investments in equity securities as fair value through net income (FV-NI). For investments in debt securities classified as AFS, the unrealized gains and losses are included in other comprehensive income until realized, at which time they are reported through net income. For investments in equity securities classified as FV-NI, both realized and unrealized gains and losses are reported through net income. Substantially all of Duke Energy’s investments in debt and equity securities qualify for regulatory accounting, and accordingly, all associated realized and unrealized gains and losses on these investments are deferred as a regulatory asset or liability. Duke Energy classifies the majority of investments in debt and equity securities as long term, unless otherwise noted. Investment Trusts The investments within the Investment Trusts are managed by independent investment managers with discretion to buy, sell and invest pursuant to the objectives set forth by the investment manager agreements and trust agreements. The Duke Energy Registrants have limited oversight of the day-to-day management of these investments. As a result, the ability to hold investments in unrealized loss positions is outside the control of the Duke Energy Registrants. Accordingly, all unrealized losses associated with debt securities within the Investment Trusts are recognized immediately and deferred to regulatory accounts where appropriate. Other AFS Securities Unrealized gains and losses on all other AFS securities are included in other comprehensive income until realized, unless it is determined the carrying value of an investment has a credit loss. The Duke Energy Registrants analyze all investment holdings each reporting period to determine whether a decline in fair value is related to a credit loss. If a credit loss exists, the unrealized credit loss is included in earnings. There were no material credit losses as of March 31, 2021, and December 31, 2020. Other Investments amounts are recorded in Other within Other Noncurrent Assets on the Condensed Consolidated Balance Sheets. DUKE ENERGY The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS. March 31, 2021 December 31, 2020 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses Value Gains Losses Value NDTF Cash and cash equivalents $ — $ — $ 193 $ — $ — $ 177 Equity securities 4,363 47 6,379 4,138 54 6,235 Corporate debt securities 38 8 793 76 1 806 Municipal bonds 13 1 299 22 — 370 U.S. government bonds 31 18 1,559 51 — 1,361 Other debt securities 5 — 184 8 — 180 Total NDTF Investments $ 4,450 $ 74 $ 9,407 $ 4,295 $ 55 $ 9,129 Other Investments Cash and cash equivalents $ — $ — $ 222 $ — $ — $ 127 Equity securities 86 — 154 79 — 146 Corporate debt securities 2 — 109 8 — 110 Municipal bonds 3 1 77 5 — 86 U.S. government bonds — 1 55 — — 42 Other debt securities — 1 36 — — 47 Total Other Investments $ 91 $ 3 $ 653 $ 92 $ — $ 558 Total Investments $ 4,541 $ 77 $ 10,060 $ 4,387 $ 55 $ 9,687 Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2021, and 2020, were as follows. Three Months Ended (in millions) March 31, 2021 March 31, 2020 FV-NI: Realized gains $ 140 $ 23 Realized losses 23 65 AFS: Realized gains 18 20 Realized losses 13 6 DUKE ENERGY CAROLINAS The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS. March 31, 2021 December 31, 2020 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses Value Gains Losses Value NDTF Cash and cash equivalents $ — $ — $ 63 $ — $ — $ 30 Equity securities 2,531 23 3,738 2,442 23 3,685 Corporate debt securities 23 5 475 49 1 510 Municipal bonds — — 22 6 — 91 U.S. government bonds 16 9 669 25 — 475 Other debt securities 4 — 178 7 — 174 Total NDTF Investments $ 2,574 $ 37 $ 5,145 $ 2,529 $ 24 $ 4,965 Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2021, and 2020, were as follows. Three Months Ended (in millions) March 31, 2021 March 31, 2020 FV-NI: Realized gains $ 128 $ 9 Realized losses 16 45 AFS: Realized gains 13 12 Realized losses 9 5 PROGRESS ENERGY The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS. March 31, 2021 December 31, 2020 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses Value Gains Losses Value NDTF Cash and cash equivalents $ — $ — $ 130 $ — $ — $ 147 Equity securities 1,832 24 2,641 1,696 31 2,550 Corporate debt securities 15 3 318 27 — 296 Municipal bonds 13 1 277 16 — 279 U.S. government bonds 15 9 890 26 — 886 Other debt securities 1 — 6 1 — 6 Total NDTF Investments $ 1,876 $ 37 $ 4,262 $ 1,766 $ 31 $ 4,164 Other Investments Cash and cash equivalents $ — $ — $ 107 $ — $ — $ 106 Municipal bonds 2 — 26 3 — 26 Total Other Investments $ 2 $ — $ 133 $ 3 $ — $ 132 Total Investments $ 1,878 $ 37 $ 4,395 $ 1,769 $ 31 $ 4,296 Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2021, and 2020, were as follows. Three Months Ended (in millions) March 31, 2021 March 31, 2020 FV-NI: Realized gains $ 12 $ 14 Realized losses 7 20 AFS: Realized gains 4 5 Realized losses 3 1 DUKE ENERGY PROGRESS The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS. March 31, 2021 December 31, 2020 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses Value Gains Losses Value NDTF Cash and cash equivalents $ — $ — $ 95 $ — $ — $ 76 Equity securities 1,746 24 2,547 1,617 31 2,459 Corporate debt securities 15 3 291 27 — 296 Municipal bonds 13 1 277 16 — 279 U.S. government bonds 15 4 429 26 — 412 Other debt securities 1 — 6 1 — 6 Total NDTF Investments $ 1,790 $ 32 $ 3,645 $ 1,687 $ 31 $ 3,528 Other Investments Cash and cash equivalents $ — $ — $ 1 $ — $ — $ 1 Total Other Investments $ — $ — $ 1 $ — $ — $ 1 Total Investments $ 1,790 $ 32 $ 3,646 $ 1,687 $ 31 $ 3,529 Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2021, and 2020, were as follows. Three Months Ended (in millions) March 31, 2021 March 31, 2020 FV-NI: Realized gains $ 12 $ 14 Realized losses 7 20 AFS: Realized gains 4 5 Realized losses 3 1 DUKE ENERGY FLORIDA The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS. March 31, 2021 December 31, 2020 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses Value Gains Losses Value NDTF Cash and cash equivalents $ — $ — $ 35 $ — $ — $ 71 Equity securities 86 — 94 79 — 91 Corporate debt securities — — 27 — — — U.S. government bonds — 5 461 — — 474 Total NDTF Investments (a) $ 86 $ 5 $ 617 $ 79 $ — $ 636 Other Investments Cash and cash equivalents $ — $ — $ 2 $ — $ — $ 1 Municipal bonds 2 — 26 3 — 26 Total Other Investments $ 2 $ — $ 28 $ 3 $ — $ 27 Total Investments $ 88 $ 5 $ 645 $ 82 $ — $ 663 (a) During the three months ended March 31, 2021, and the year ended December 31, 2020, Duke Energy Florida received reimbursements from the NDTF for costs related to ongoing decommissioning activity of Crystal River Unit 3. Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2021, and 2020, were immaterial. DUKE ENERGY INDIANA The following table presents the estimated fair value of investments in debt and equity securities; equity investments are measured at FV-NI and debt investments are classified as AFS. March 31, 2021 December 31, 2020 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses Value Gains Losses Value Investments Cash and cash equivalents $ — $ — $ — $ — $ — $ 1 Equity securities 62 — 102 58 — 97 Corporate debt securities — — 4 — — 3 Municipal bonds 1 1 35 1 — 38 U.S. government bonds — — 6 — — 4 Total Investments $ 63 $ 1 $ 147 $ 59 $ — $ 143 Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2021, and 2020, were immaterial. DEBT SECURITY MATURITIES The table below summarizes the maturity date for debt securities. March 31, 2021 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Indiana Due in one year or less $ 152 $ 7 $ 116 $ 18 $ 98 $ 5 Due after one through five years 1,013 375 579 267 312 18 Due after five through 10 years 693 310 289 217 72 9 Due after 10 years 1,254 652 533 501 32 13 Total $ 3,112 $ 1,344 $ 1,517 $ 1,003 $ 514 $ 45

Fair Value Measurements

Fair Value Measurements	3 Months Ended
Fair Value Measurements	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS Fair value is the exchange price to sell an asset or transfer a liability in an orderly transaction between market participants at the measurement date. The fair value definition focuses on an exit price versus the acquisition cost. Fair value measurements use market data or assumptions market participants would use in pricing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs may be readily observable, corroborated by market data or generally unobservable. Valuation techniques maximize the use of observable inputs and minimize use of unobservable inputs. A midmarket pricing convention (the midpoint price between bid and ask prices) is permitted for use as a practical expedient. Fair value measurements are classified in three levels based on the fair value hierarchy as defined by GAAP. Certain investments are not categorized within the fair value hierarchy. These investments are measured at fair value using the net asset value (NAV) per share practical expedient. The NAV is derived based on the investment cost, less any impairment, plus or minus changes resulting from observable price changes for an identical or similar investment of the same issuer. Fair value accounting guidance permits entities to elect to measure certain financial instruments that are not required to be accounted for at fair value, such as equity method investments or the company’s own debt, at fair value. The Duke Energy Registrants have not elected to record any of these items at fair value. Valuation methods of the primary fair value measurements disclosed below are as follows. Investments in equity securities The majority of investments in equity securities are valued using Level 1 measurements. Investments in equity securities are typically valued at the closing price in the principal active market as of the last business day of the quarter. Principal active markets for equity prices include published exchanges such as the New York Stock Exchange and Nasdaq Stock Market. Foreign equity prices are translated from their trading currency using the currency exchange rate in effect at the close of the principal active market. There was no after-hours market activity that was required to be reflected in the reported fair value measurements. Investments in debt securities Most investments in debt securities are valued using Level 2 measurements because the valuations use interest rate curves and credit spreads applied to the terms of the debt instrument (maturity and coupon interest rate) and consider the counterparty credit rating. If the market for a particular fixed-income security is relatively inactive or illiquid, the measurement is Level 3. Commodity derivatives Commodity derivatives with clearinghouses are classified as Level 1. Commodity derivatives with observable forward curves are classified as Level 2. If forward price curves are not observable for the full term of the contract and the unobservable period had more than an insignificant impact on the valuation, the commodity derivative is classified as Level 3. In isolation, increases (decreases) in natural gas forward prices result in favorable (unfavorable) fair value adjustments for natural gas purchase contracts; and increases (decreases) in electricity forward prices result in unfavorable (favorable) fair value adjustments for electricity sales contracts. Duke Energy regularly evaluates and validates pricing inputs used to estimate the fair value of natural gas commodity contracts by a market participant price verification procedure. This procedure provides a comparison of internal forward commodity curves to market participant generated curves. Interest rate derivatives Most over-the-counter interest rate contract derivatives are valued using financial models that utilize observable inputs for similar instruments and are classified as Level 2. Inputs include forward interest rate curves, notional amounts, interest rates and credit quality of the counterparties. Other fair value considerations See Note 11 in Duke Energy's Annual Report on Form 10-K for the year ended December 31, 2020, for a discussion of the valuation of goodwill and intangible assets. DUKE ENERGY The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. Derivative amounts in the tables below for all Duke Energy Registrants exclude cash collateral, which is disclosed in Note 8. See Note 9 for additional information related to investments by major security type for the Duke Energy Registrants. March 31, 2021 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not Categorized NDTF cash and cash equivalents $ 193 $ 193 $ — $ — $ — NDTF equity securities 6,379 6,332 — — 47 NDTF debt securities 2,835 1,019 1,816 — — Other equity securities 154 154 — — — Other debt securities 277 49 228 — — Other cash and cash equivalents 222 222 — — — Derivative assets 206 1 203 2 — Total assets 10,266 7,970 2,247 2 47 Derivative liabilities (349) — (221) (128) — Net assets (liabilities) $ 9,917 $ 7,970 $ 2,026 $ (126) $ 47 December 31, 2020 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not Categorized NDTF cash and cash equivalents $ 177 $ 177 $ — $ — $ — NDTF equity securities 6,235 6,189 — — 46 NDTF debt securities 2,717 874 1,843 — — Other equity securities 146 146 — — — Other debt securities 285 37 248 — — Other cash and cash equivalents 127 127 — — — Derivative assets 61 1 53 7 — Total assets 9,748 7,551 2,144 7 46 Derivative liabilities (324) — (240) (84) — Net assets (liabilities) $ 9,424 $ 7,551 $ 1,904 $ (77) $ 46 The following tables provide reconciliations of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements. Derivatives (net) Three Months Ended March 31, (in millions) 2021 2020 Balance at beginning of period $ (77) $ (102) Total pretax realized or unrealized losses included in comprehensive income (44) — Purchases, sales, issuances and settlements: Settlements (7) (9) Total gains included on the Condensed Consolidated Balance Sheet 2 23 Balance at end of period $ (126) $ (88) DUKE ENERGY CAROLINAS The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. March 31, 2021 (in millions) Total Fair Value Level 1 Level 2 Not Categorized NDTF cash and cash equivalents $ 63 $ 63 $ — $ — NDTF equity securities 3,738 3,691 — 47 NDTF debt securities 1,344 369 975 — Derivative assets 62 — 62 — Total assets 5,207 4,123 1,037 47 December 31, 2020 (in millions) Total Fair Value Level 1 Level 2 Not Categorized NDTF cash and cash equivalents $ 30 $ 30 $ — $ — NDTF equity securities 3,685 3,639 — 46 NDTF debt securities 1,250 192 1,058 — Derivative assets 20 — 20 — Total assets 4,985 3,861 1,078 46 Derivative liabilities (20) — (20) — Net assets $ 4,965 $ 3,861 $ 1,058 $ 46 PROGRESS ENERGY The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. March 31, 2021 December 31, 2020 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 NDTF cash and cash equivalents $ 130 $ 130 $ — $ 147 $ 147 $ — NDTF equity securities 2,641 2,641 — 2,550 2,550 — NDTF debt securities 1,491 650 841 1,467 682 785 Other debt securities 26 — 26 26 — 26 Other cash and cash equivalents 107 107 — 106 106 — Derivative assets 103 — 103 33 — 33 Total assets 4,498 3,528 970 4,329 3,485 844 Derivative liabilities (28) — (28) (29) — (29) Net assets $ 4,470 $ 3,528 $ 942 $ 4,300 $ 3,485 $ 815 DUKE ENERGY PROGRESS The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. March 31, 2021 December 31, 2020 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 NDTF cash and cash equivalents $ 95 $ 95 $ — $ 76 $ 76 $ — NDTF equity securities 2,547 2,547 — 2,459 2,459 — NDTF debt securities 1,003 237 766 993 237 756 Other cash and cash equivalents 1 1 — 1 1 — Derivative assets 100 — 100 33 — 33 Total assets 3,746 2,880 866 3,562 2,773 789 Derivative liabilities (9) — (9) (14) — (14) Net assets $ 3,737 $ 2,880 $ 857 $ 3,548 $ 2,773 $ 775 DUKE ENERGY FLORIDA The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. March 31, 2021 December 31, 2020 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 NDTF cash and cash equivalents $ 35 $ 35 $ — $ 71 $ 71 $ — NDTF equity securities 94 94 — 91 91 — NDTF debt securities 488 413 75 474 445 29 Other debt securities 26 — 26 26 — 26 Other cash and cash equivalents 2 2 — 1 1 — Derivative assets 3 — 3 — — — Total assets 648 544 104 663 608 55 Derivative liabilities (3) — (3) — — — Net assets $ 645 $ 544 $ 101 $ 663 $ 608 $ 55 DUKE ENERGY OHIO The recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets were not material at March 31, 2021, and December 31, 2020 . DUKE ENERGY INDIANA The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. March 31, 2021 December 31, 2020 (in millions) Total Fair Value Level 1 Level 2 Level 3 Total Fair Value Level 1 Level 2 Level 3 Other equity securities $ 102 $ 102 $ — $ — $ 97 $ 97 $ — $ — Other debt securities 45 — 45 — 45 — 45 — Other cash and cash equivalents — — — — 1 1 — — Derivative assets 2 — — 2 6 — — 6 Total assets $ 149 $ 102 $ 45 $ 2 $ 149 $ 98 $ 45 $ 6 Derivative liabilities — — — — (1) (1) — — Net assets $ 149 $ 102 $ 45 $ 2 $ 148 $ 97 $ 45 $ 6 The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements. Derivatives (net) Three Months Ended March 31, (in millions) 2021 2020 Balance at beginning of period $ 6 $ 11 Purchases, sales, issuances and settlements: Settlements (6) (6) Total gains (losses) included on the Condensed Consolidated Balance Sheet 2 (3) Balance at end of period $ 2 $ 2 PIEDMONT The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. March 31, 2021 December 31, 2020 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 Derivative assets $ 1 $ 1 $ — $ 1 $ 1 $ — Derivative liabilities (148) — (148) (122) — (122) Net (liabilities) assets $ (147) $ 1 $ (148) $ (121) $ 1 $ (122) The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements. Derivatives (net) Three Months Ended March 31, (in millions) 2021 2020 Balance at beginning of period $ — $ (117) Total gains and settlements — 26 Balance at end of period $ — $ (91) QUANTITATIVE INFORMATION ABOUT UNOBSERVABLE INPUTS The following tables include quantitative information about the Duke Energy Registrants' derivatives classified as Level 3. March 31, 2021 Weighted Fair Value Average Investment Type (in millions) Valuation Technique Unobservable Input Range Range Duke Energy Electricity contracts $ (128) RTO forward pricing Forward electricity curves – price per MWh $ 15.55 - $ 134.48 $ 34.80 Duke Energy Indiana FTRs 2 RTO auction pricing FTR price – per MWh (1.02) - 7.23 0.80 Duke Energy Total Level 3 derivatives $ (126) December 31, 2020 Weighted Fair Value Average Investment Type (in millions) Valuation Technique Unobservable Input Range Range Duke Energy Electricity contracts $ (84) Discounted cash flow Forward electricity curves – price per MWh $ 14.68 - $151.84 $28.84 Duke Energy Ohio FTRs 1 RTO auction pricing FTR price – per MWh 0.25 - 1.68 0.79 Duke Energy Indiana FTRs 6 RTO auction pricing FTR price – per MWh (2.40) - 7.41 1.05 Duke Energy Total Level 3 derivatives $ (77) OTHER FAIR VALUE DISCLOSURES The fair value and book value of long-term debt, including current maturities, is summarized in the following table. Estimates determined are not necessarily indicative of amounts that could have been settled in current markets. Fair value of long-term debt uses Level 2 measurements. March 31, 2021 December 31, 2020 (in millions) Book Value Fair Value Book Value Fair Value Duke Energy (a) $ 60,354 $ 64,641 $ 59,863 $ 69,292 Duke Energy Carolinas 12,329 13,461 12,218 14,917 Progress Energy 19,333 21,838 19,264 23,470 Duke Energy Progress 9,356 10,131 9,258 10,862 Duke Energy Florida 7,884 9,018 7,915 9,756 Duke Energy Ohio 3,090 3,397 3,089 3,650 Duke Energy Indiana 4,091 4,691 4,091 5,204 Piedmont 3,127 3,412 2,780 3,306 (a) Book value of long-term debt inc ludes $1.3 billion at March 31, 2021, and December 31, 2020, of unamortized debt discount and premium, net of purchase accounting adjustments related to the mergers with Progress Energy and Piedmont that are excluded from fair value of long-term debt. At both March 31, 2021, and December 31, 2020, fair value of cash and cash equivalents, accounts and notes receivable, accounts payable, notes payable and commercial paper and nonrecourse notes payable of VIEs are not materially different from their carrying amounts because of the short-term nature of these instruments and/or because the stated rates approximate market rates.

Variable Interest Entities

Variable Interest Entities	3 Months Ended
Variable Interest Entities	Mar. 31, 2021
Variable Interest Entities [Abstract]
Variable Interest Entities	VARIABLE INTEREST ENTITIES CONSOLIDATED VIEs The obligations of the consolidated VIEs discussed in the following paragraphs are nonrecourse to the Duke Energy Registrants. The registrants have no requirement to provide liquidity to, purchase assets of or guarantee performance of these VIEs unless noted in the following paragraphs. No financial support was provided to any of the consolidated VIEs during the three months ended March 31, 2021, and the year ended December 31, 2020, or is expected to be provided in the future that was not previously contractually required. Receivables Financing – DERF/DEPR/DEFR DERF, DEPR and DEFR are bankruptcy remote, special purpose subsidiaries of Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida, respectively. DERF, DEPR and DEFR are wholly owned LLCs with separate legal existence from their parent companies, and their assets are not generally available to creditors of their parent companies. On a revolving basis, DERF, DEPR and DEFR buy certain accounts receivable arising from the sale of electricity and related services from their parent companies. DERF, DEPR and DEFR borrow amounts under credit facilities to buy these receivables. Borrowing availability from the credit facilities is limited to the amount of qualified receivables purchased, which generally exclude receivables past due more than a predetermined number of days and reserves for expected past-due balances. The sole source of funds to satisfy the related debt obligations is cash collections from the receivables. Amounts borrowed under the credit facilities for DERF and DEPR are reflected on the Condensed Consolidated Balance Sheets as Long-Term Debt. Amounts borrowed under the credit facilities for DEFR are reflected on the Condensed Consolidated Balance Sheets as Current maturities of long-term debt. The most significant activity that impacts the economic performance of DERF, DEPR and DEFR are the decisions made to manage delinquent receivables. Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida are considered the primary beneficiaries and consolidate DERF, DEPR and DEFR, respectively, as they make those decisions. Receivables Financing – CRC CRC is a bankruptcy remote, special purpose entity indirectly owned by Duke Energy. On a revolving basis, CRC buys certain accounts receivable arising from the sale of electricity, natural gas and related services from Duke Energy Ohio and Duke Energy Indiana. CRC borrows amounts under a credit facility to buy the receivables from Duke Energy Ohio and Duke Energy Indiana. Borrowing availability from the credit facility is limited to the amount of qualified receivables sold to CRC, which generally exclude receivables past due more than a predetermined number of days and reserves for expected past-due balances. The sole source of funds to satisfy the related debt obligation is cash collections from the receivables. Amounts borrowed under the credit facility are reflected on Duke Energy's Condensed Consolidated Balance Sheets as Long-Term Debt. The proceeds Duke Energy Ohio and Duke Energy Indiana receive from the sale of receivables to CRC are approximately 75% cash and 25% in the form of a subordinated note from CRC. The subordinated note is a retained interest in the receivables sold. Depending on collection experience, additional equity infusions to CRC may be required by Duke Energy to maintain a minimum equity balance of $3 million. CRC is considered a VIE because (i) equity capitalization is insufficient to support its operations, (ii) power to direct the activities that most significantly impact the economic performance of the entity is not held by the equity holder and (iii) deficiencies in net worth of CRC are funded by Duke Energy. The most significant activities that impact the economic performance of CRC are decisions made to manage delinquent receivables. Duke Energy is considered the primary beneficiary and consolidates CRC as it makes these decisions. Neither Duke Energy Ohio nor Duke Energy Indiana consolidate CRC. Receivables Financing – Credit Facilities The following table summarizes the amounts and expiration dates of the credit facilities and associated restricted receivables described above. Duke Energy Duke Energy Duke Energy Duke Energy Carolinas Progress Florida (in millions) CRC DERF DEPR DEFR Expiration date February 2023 December 2022 April 2023 April 2023 Credit facility amount $ 350 $ 475 $ 350 $ 250 Amounts borrowed at March 31, 2021 350 430 350 250 Amounts borrowed at December 31, 2020 350 364 250 250 Restricted Receivables at March 31, 2021 472 613 422 323 Restricted Receivables at December 31, 2020 547 696 500 397 Nuclear Asset-Recovery Bonds – DEFPF DEFPF is a bankruptcy remote, wholly owned special purpose subsidiary of Duke Energy Florida. DEFPF was formed in 2016 for the sole purpose of issuing nuclear asset-recovery bonds to finance Duke Energy Florida's unrecovered regulatory asset related to Crystal River Unit 3. In 2016, DEFPF issued senior secured bonds and used the proceeds to acquire nuclear asset-recovery property from Duke Energy Florida. The nuclear asset-recovery property acquired includes the right to impose, bill, collect and adjust a non-bypassable nuclear asset-recovery charge from all Duke Energy Florida retail customers until the bonds are paid in full and all financing costs have been recovered. The nuclear asset-recovery bonds are secured by the nuclear asset-recovery property and cash collections from the nuclear asset-recovery charges are the sole source of funds to satisfy the debt obligation. The bondholders have no recourse to Duke Energy Florida. DEFPF is considered a VIE primarily because the equity capitalization is insufficient to support its operations. Duke Energy Florida has the power to direct the significant activities of the VIE as described above and therefore Duke Energy Florida is considered the primary beneficiary and consolidates DEFPF. The following table summarizes the impact of DEFPF on Duke Energy Florida's Condensed Consolidated Balance Sheets. (in millions) March 31, 2021 December 31, 2020 Receivables of VIEs $ 4 $ 4 Regulatory Assets: Current 54 53 Current Assets: Other 14 39 Other Noncurrent Assets: Regulatory assets 927 937 Current Liabilities: Other 2 10 Current maturities of long-term debt 55 55 Long-Term Debt 972 1,002 Commercial Renewables Certain of Duke Energy’s renewable energy facilities are VIEs due to Duke Energy issuing guarantees for debt service and operations and maintenance reserves in support of debt financings. Assets are restricted and cannot be pledged as collateral or sold to third parties without prior approval of debt holders. Additionally, Duke Energy has VIEs associated with tax equity arrangements entered into with third-party investors in order to finance the cost of renewable assets eligible for tax credits. The activities that most significantly impacted the economic performance of these renewable energy facilities were decisions associated with siting, negotiating PPAs and Engineering, Procurement and Construction agreements, and decisions associated with ongoing operations and maintenance-related activities. Duke Energy is considered the primary beneficiary and consolidates the entities as it is responsible for all of these decisions. The table below presents material balances reported on Duke Energy's Condensed Consolidated Balance Sheets related to Commercial Renewables VIEs. (in millions) March 31, 2021 December 31, 2020 Current Assets: Other $ 319 $ 257 Property, Plant and Equipment: Cost 6,860 6,394 Accumulated depreciation and amortization (1,297) (1,242) Other Noncurrent Assets: Other 66 67 Current maturities of long-term debt 167 167 Long-Term Debt 1,584 1,569 Other Noncurrent Liabilities: AROs 153 148 Other Noncurrent Liabilities: Other 331 316 NON-CONSOLIDATED VIEs The following tables summarize the impact of non-consolidated VIEs on the Condensed Consolidated Balance Sheets. March 31, 2021 Duke Energy Duke Duke Pipeline Commercial Energy Energy (in millions) Investments Renewables Total Ohio Indiana Receivables from affiliated companies $ — $ — $ — $ 46 $ 60 Other current assets 4 — 4 — $ — Investments in equity method unconsolidated affiliates 3 480 483 — — Deferred tax asset 29 — 29 — — Total assets $ 36 $ 480 $ 516 $ 46 $ 60 Other current liabilities 38 3 41 — — Other noncurrent liabilities 48 10 58 — — Total liabilities $ 86 $ 13 $ 99 $ — $ — Net (liabilities) assets $ (50) $ 467 $ 417 $ 46 $ 60 December 31, 2020 Duke Energy Duke Duke Pipeline Commercial Energy Energy (in millions) Investments Renewables Total Ohio Indiana Receivables from affiliated companies $ — $ — $ — $ 83 $ 110 Investments in equity method unconsolidated affiliates — 530 530 — — Other noncurrent assets 31 — 31 — — Total assets $ 31 $ 530 $ 561 $ 83 $ 110 Other current liabilities 928 5 933 — — Other noncurrent liabilities 8 10 18 — — Total liabilities $ 936 $ 15 $ 951 $ — $ — Net assets (liabilities) $ (905) $ 515 $ (390) $ 83 $ 110 The Duke Energy Registrants are not aware of any situations where the maximum exposure to loss significantly exceeds the carrying values shown above except for future exit costs associated with the cancellation of the ACP pipeline and certain renewable energy project entities guarantees for debt services and operations and maintenance, as discussed below. Pipeline Investments Duke Energy has investments in various joint ventures to construct and operate pipeline projects. These entities are considered VIEs due to having insufficient equity to finance their own activities without subordinated financial support. Duke Energy does not have the power to direct the activities that most significantly impact the economic performance, the obligation to absorb losses or the right to receive benefits of these VIEs and therefore does not consolidate these entities. Duke Energy has a 47% ownership interest in ACP. In 2020, Duke Energy determined that it would no longer invest in the construction of the ACP pipeline. In February 2021, Duke Energy paid approximately $855 million to fund ACP's outstanding debt, relieving Duke Energy of its guarantee. See Notes 1 and 3 for further information regarding this transaction. Commercial Renewables Duke Energy has investments in various renewable energy project entities. Some of these entities are VIEs due to Duke Energy issuing guarantees for debt service and operations and maintenance reserves in support of debt financings. Duke Energy does not consolidate these VIEs because power to direct and control key activities is shared jointly by Duke Energy and other owners. OVEC Duke Energy Ohio’s 9% ownership interest in OVEC is considered a non-consolidated VIE due to OVEC having insufficient equity to finance its activities without subordinated financial support. The activities that most significantly impact OVEC's economic performance include fuel strategy and supply activities and decisions associated with ongoing operations and maintenance-related activities. Duke Energy Ohio does not have the unilateral power to direct these activities, and therefore, does not consolidate OVEC. As a counterparty to an Inter-Company Power Agreement (ICPA), Duke Energy Ohio has a contractual arrangement to receive entitlements to capacity and energy from OVEC’s power plants through June 2040 commensurate with its power participation ratio, which is equivalent to Duke Energy Ohio's ownership interest. Costs, including fuel, operating expenses, fixed costs, debt amortization and interest expense, are allocated to counterparties to the ICPA based on their power participation ratio. The value of the ICPA is subject to variability due to fluctuation in power prices and changes in OVEC's cost of business. Duke Energy cannot predict the outcome in this matter. See Note 3 for additional information. CRC See discussion under Consolidated VIEs for additional information related to CRC. Amounts included in Receivables from affiliated companies in the above table for Duke Energy Ohio and Duke Energy Indiana reflect their retained interest in receivables sold to CRC. These subordinated notes held by Duke Energy Ohio and Duke Energy Indiana are stated at fair value. The following table shows the gross and net receivables sold. Duke Energy Ohio Duke Energy Indiana (in millions) March 31, 2021 December 31, 2020 March 31, 2021 December 31, 2020 Receivables sold $ 241 $ 270 $ 285 $ 344 Less: Retained interests 46 83 60 110 Net receivables sold $ 195 $ 187 $ 225 $ 234 The following table shows sales and cash flows related to receivables sold. Duke Energy Ohio Duke Energy Indiana Three Months Ended Three Months Ended March 31, March 31, (in millions) 2021 2020 2021 2020 Sales Receivables sold $ 561 $ 537 $ 698 $ 647 Loss recognized on sale 3 4 3 4 Cash flows Cash proceeds from receivables sold $ 596 $ 559 $ 746 $ 672 Return received on retained interests 1 2 2 2 Cash flows from sales of receivables are reflected within Cash Flows From Operating Activities and Cash Flows from Investing Activities on Duke Energy Ohio’s and Duke Energy Indiana’s Condensed Consolidated Statements of Cash Flows.

Revenue

Revenue	3 Months Ended
Revenue	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Revenue	REVENUEDuke Energy earns substantially all of its revenues through its reportable segments, Electric Utilities and Infrastructure, Gas Utilities and Infrastructure and Commercial Renewables. Electric Utilities and Infrastructure Electric Utilities and Infrastructure earns the majority of its revenues through retail and wholesale electric service through the generation, transmission, distribution and sale of electricity. Duke Energy generally provides retail and wholesale electric service customers with their full electric load requirements or with supplemental load requirements when the customer has other sources of electricity. The majority of wholesale revenues are full requirements contracts where the customers purchase the substantial majority of their energy needs and do not have a fixed quantity of contractually required energy or capacity. As such, related forecasted revenues are considered optional purchases. Supplemental requirements contracts that include contracted blocks of energy and capacity at contractually fixed prices have the following estimated remaining performance obligations: Remaining Performance Obligations (in millions) 2021 2022 2023 2024 2025 Thereafter Total Progress Energy $ 71 $ 107 $ 44 $ 45 $ 7 $ 51 $ 325 Duke Energy Progress 6 8 8 8 — — 30 Duke Energy Florida 65 99 36 37 7 51 295 Duke Energy Indiana 2 — 7 12 12 24 57 Revenues for block sales are recognized monthly as energy is delivered and stand-ready service is provided, consistent with invoiced amounts and unbilled estimates. Gas Utilities and Infrastructure Gas Utilities and Infrastructure earns its revenue through retail and wholesale natural gas service through the transportation, distribution and sale of natural gas. Duke Energy generally provides retail and wholesale natural gas service customers with all natural gas load requirements. Additionally, while natural gas can be stored, substantially all natural gas provided by Duke Energy is consumed by customers simultaneously with receipt of delivery. Fixed-capacity payments under long-term contracts for the Gas Utilities and Infrastructure segment include minimum margin contracts and supply arrangements with municipalities and power generation facilities. Revenues for related sales are recognized monthly as natural gas is delivered and stand-ready service is provided, consistent with invoiced amounts and unbilled estimates. Estimated remaining performance obligations are as follows: Remaining Performance Obligations (in millions) 2021 2022 2023 2024 2025 Thereafter Total Piedmont $ 50 $ 67 $ 64 $ 61 $ 60 $ 335 $ 637 Commercial Renewables Commercial Renewables earns the majority of its revenues through long-term PPAs and generally sells all of its wind and solar facility output, electricity and Renewable Energy Certificates (RECs) to customers. The majority of these PPAs have historically been accounted for as leases. For PPAs that are not accounted for as leases, the delivery of electricity and the delivery of RECs are considered separate performance obligations. Other The remainder of Duke Energy’s operations is presented as Other, which does not include material revenues from contracts with customers. Disaggregated Revenues Disaggregated revenues are presented as follows: Three Months Ended March 31, 2021 Duke Duke Duke Duke Duke (in millions) Duke Energy Progress Energy Energy Energy Energy By market or type of customer Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Electric Utilities and Infrastructure Residential $ 2,462 $ 793 $ 1,162 $ 560 $ 602 $ 195 $ 313 $ — General 1,419 502 624 306 318 104 189 — Industrial 662 256 207 145 62 31 167 — Wholesale 504 114 326 292 34 13 50 — Other revenues 226 74 160 83 77 22 18 — Total Electric Utilities and Infrastructure revenue from contracts with customers $ 5,273 $ 1,739 $ 2,479 $ 1,386 $ 1,093 $ 365 $ 737 $ — Gas Utilities and Infrastructure Residential $ 460 $ — $ — $ — $ — $ 110 $ — $ 351 Commercial 204 — — — — 48 — 156 Industrial 50 — — — — 7 — 43 Power Generation — — — — — — — 22 Other revenues 47 — — — — 5 — 26 Total Gas Utilities and Infrastructure revenue from contracts with customers $ 761 $ — $ — $ — $ — $ 170 $ — $ 598 Commercial Renewables Revenue from contracts with customers $ 54 $ — $ — $ — $ — $ — $ — $ — Other Revenue from contracts with customers $ 6 $ — $ — $ — $ — $ — $ — $ — Total revenue from contracts with customers $ 6,094 $ 1,739 $ 2,479 $ 1,386 $ 1,093 $ 535 $ 737 $ 598 Other revenue sources (a) $ 56 $ (23) $ 26 $ 15 $ 8 $ (3) $ 8 $ 8 Total revenues $ 6,150 $ 1,716 $ 2,505 $ 1,401 $ 1,101 $ 532 $ 745 $ 606 (a) Other revenue sources include revenues from leases, derivatives and alternative revenue programs that are not considered revenues from contracts with customers. Alternative revenue programs in certain jurisdictions include regulatory mechanisms that periodically adjust for over or under collection of related revenues. Three Months Ended March 31, 2020 Duke Duke Duke Duke Duke (in millions) Duke Energy Progress Energy Energy Energy Energy By market or type of customer Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Electric Utilities and Infrastructure Residential $ 2,261 $ 756 $ 1,064 $ 502 $ 562 $ 176 $ 265 $ — General 1,492 549 648 319 329 114 181 — Industrial 693 269 216 154 62 35 175 — Wholesale 497 114 321 279 42 7 55 — Other revenues 191 60 118 63 55 20 16 — Total Electric Utilities and Infrastructure revenue from contracts with customers $ 5,134 $ 1,748 $ 2,367 $ 1,317 $ 1,050 $ 352 $ 692 $ — Gas Utilities and Infrastructure Residential $ 362 $ — $ — $ — $ — $ 97 $ — $ 264 Commercial 169 — — — — 43 — 126 Industrial 41 — — — — 6 — 36 Power Generation — — — — — — — 11 Other revenues 30 — — — — 6 — 24 Total Gas Utilities and Infrastructure revenue from contracts with customers $ 602 $ — $ — $ — $ — $ 152 $ — $ 461 Commercial Renewables Revenue from contracts with customers $ 58 $ — $ — $ — $ — $ — $ — $ — Other Revenue from contracts with customers $ 6 $ — $ — $ — $ — $ — $ — $ — Total revenue from contracts with customers $ 5,800 $ 1,748 $ 2,367 $ 1,317 $ 1,050 $ 504 $ 692 $ 461 Other revenue sources (a) $ 149 $ — $ 55 $ 21 $ 30 $ (6) $ — $ 51 Total revenues $ 5,949 $ 1,748 $ 2,422 $ 1,338 $ 1,080 $ 498 $ 692 $ 512 (a) Other revenue sources include revenues from leases, derivatives and alternative revenue programs that are not considered revenues from contracts with customers. Alternative revenue programs in certain jurisdictions include regulatory mechanisms that periodically adjust for over or under collection of related revenues. Three Months Ended March 31, 2020 and 2021 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Balance at December 31, 2019 $ 76 $ 10 $ 16 $ 8 $ 7 $ 4 $ 3 $ 6 Cumulative Change in Accounting Principle 5 1 2 1 1 — — 1 Write-Offs (10) (3) (4) (2) (2) — — (1) Credit Loss Expense 18 3 6 2 5 1 — 3 Balance at March 31, 2020 $ 89 $ 11 $ 20 $ 9 $ 11 $ 5 $ 3 $ 9 Balance at December 31, 2020 $ 146 $ 23 $ 37 $ 23 $ 14 $ 4 $ 3 $ 12 Write-Offs (21) (8) (10) (5) (5) — — (1) Credit Loss Expense 17 10 7 2 5 — — 3 Other Adjustments 5 9 3 3 1 — — — Balance at March 31, 2021 $ 147 $ 34 $ 37 $ 23 $ 15 $ 4 $ 3 $ 14 Trade and other receivables are evaluated based on an estimate of the risk of loss over the life of the receivable and current and historical conditions using supportable assumptions. Management evaluates the risk of loss for trade and other receivables by comparing the historical write-off amounts to total revenue over a specified period. Historical loss rates are adjusted due to the impact of current conditions, as well as forecasted conditions over a reasonable time period. The calculated write-off rate can be applied to the receivable balance for which an established reserve does not already exist. Management reviews the assumptions and risk of loss periodically for trade and other receivables. The aging of trade receivables is presented in the table below. Duke Energy considers receivables greater than 30 days outstanding past due. March 31, 2021 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Unbilled Revenue (a)(b) $ 758 $ 293 $ 183 $ 90 $ 93 $ 4 $ 16 $ 44 0-30 days 1,656 337 633 357 275 55 35 185 30-60 days 181 62 46 31 15 8 3 21 60-90 days 46 15 11 6 5 3 1 6 90+ days 120 31 26 4 22 28 11 7 Deferred Payment Arrangements (c) 170 80 53 37 16 4 — 8 Trade and Other Receivables $ 2,931 $ 818 $ 952 $ 525 $ 426 $ 102 $ 66 $ 271 December 31, 2020 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Unbilled Revenue (a)(b) $ 969 $ 328 $ 283 $ 167 $ 116 $ 2 $ 16 $ 86 0-30 days 1,789 445 707 398 307 60 26 149 30-60 days 185 80 54 25 29 8 3 8 60-90 days 22 1 10 4 6 2 1 3 90+ days 119 16 32 9 23 30 12 9 Deferred Payment Arrangements (c) 215 96 80 52 28 — — 7 Trade and Other Receivables $ 3,299 $ 966 $ 1,166 $ 655 $ 509 $ 102 $ 58 $ 262 (a) Unbilled revenues are recognized by applying customer billing rates to the estimated volumes of energy or natural gas delivered but not yet billed and are included within Receivables and Receivables of VIEs on the Condensed Consolidated Balance Sheets. (b) Duke Energy Ohio and Duke Energy Indiana sell, on a revolving basis, nearly all of their retail accounts receivable, including receivables for unbilled revenues, to an affiliate, CRC, and account for the transfers of receivables as sales. Accordingly, the receivables sold are not reflected on the Condensed Consolidated Balance Sheets of Duke Energy Ohio and Duke Energy Indiana. See Note 11 for further information. These receivables for unbilled revenues are $55 million and $87 million for Duke Energy Ohio and Duke Energy Indiana, respectively, as of March 31, 2021, and $87 million and $134 million for Duke Energy Ohio and Duke Energy Indiana, respectively, as of December 31, 2020. (c) Due to certain customer financial hardships created by the COVID-19 pandemic and resulting stay-at-home orders, Duke Energy permitted customers to defer payment of past-due amounts through an installment payment plan over a period of several months.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
Stockholders' Equity	Mar. 31, 2021
Equity [Abstract]
Stockholders' Equity	STOCKHOLDERS' EQUITYBasic EPS is computed by dividing net income available to Duke Energy common stockholders, as adjusted for distributed and undistributed earnings allocated to participating securities and accumulated preferred dividends, by the weighted average number of common shares outstanding during the period. Diluted EPS is computed by dividing net income available to Duke Energy common stockholders, as adjusted for distributed and undistributed earnings allocated to participating securities and accumulated preferred dividends, by the diluted weighted average number of common shares outstanding during the period. Diluted EPS reflects the potential dilution that could occur if securities or other agreements to issue common stock, such as equity forward sale agreements, were exercised or settled. Duke Energy’s participating securities are restricted stock units that are entitled to dividends declared on Duke Energy common stock during the restricted stock unit’s vesting periods. Dividends declared on preferred stock are recorded on the Condensed Consolidated Statements of Operations as a reduction of net income to arrive at net income available to Duke Energy common stockholders. Dividends accumulated on preferred stock are an adjustment to net income used in the calculation of basic and diluted EPS. The following table presents Duke Energy’s basic and diluted EPS calculations, the weighted average number of common shares outstanding and common and preferred share dividends declared. Three Months Ended March 31, (in millions, except per share amounts) 2021 2020 Net income available to Duke Energy common stockholders $ 953 $ 899 Accumulated preferred stock dividends adjustment 12 13 Less: Impact of participating securities 1 1 Income from continuing operations available to Duke Energy common stockholders $ 964 $ 911 Weighted average common shares outstanding – basic 769 734 Equity forwards — 2 Weighted average common shares outstanding – diluted 769 736 EPS available to Duke Energy common stockholders Basic and diluted $ 1.25 $ 1.24 Potentially dilutive items excluded from the calculation (a) 2 2 Dividends declared per common share $ 0.965 $ 0.945 Dividends declared on Series A preferred stock per depositary share (b) $ 0.359 $ 0.359 Dividends declared on Series B preferred stock per share (c) $ 24.375 $ 24.917 (a) Performance stock awards were not included in the dilutive securities calculation because the performance measures related to the awards had not been met. (b) 5.75% Series A Cumulative Redeemable Perpetual Preferred Stock dividends are payable quarterly in arrears on the 16th day of March, June, September and December. The preferred stock has a $25 liquidation preference per depositary share. (c) 4.875% Series B Fixed-Rate Reset Cumulative Redeemable Perpetual Preferred Stock dividends are payable semiannually in arrears on the 16th day of March and September. The preferred stock has a $1,000 liquidation preference per share.

Employee Benefit Plans

Employee Benefit Plans	3 Months Ended
Employee Benefit Plans	Mar. 31, 2021
Retirement Benefits [Abstract]
Employee Benefit Plans	EMPLOYEE BENEFIT PLANS DEFINED BENEFIT RETIREMENT PLANS Duke Energy and certain subsidiaries maintain, and the Subsidiary Registrants participate in, qualified and non-qualified, non-contributory defined benefit retirement plans. Duke Energy's policy is to fund amounts on an actuarial basis to provide assets sufficient to meet benefit payments to be paid to plan participants. QUALIFIED PENSION PLANS The following tables include the components of net periodic pension costs for qualified pension plans. Three Months Ended March 31, 2021 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Service cost $ 44 $ 14 $ 13 $ 7 $ 5 $ 1 $ 2 $ 1 Interest cost on projected benefit obligation 55 13 17 7 10 3 5 2 Expected return on plan assets (139) (35) (47) (21) (26) (7) (10) (5) Amortization of actuarial loss 33 7 10 5 5 2 3 2 Amortization of prior service credit (7) (2) (1) — — — — (1) Amortization of settlement charges 2 1 1 — — — — — Net periodic pension costs $ (12) $ (2) $ (7) $ (2) $ (6) $ (1) $ — $ (1) Three Months Ended March 31, 2020 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Service cost $ 41 $ 12 $ 12 $ 6 $ 5 $ 1 $ 2 $ 1 Interest cost on projected benefit obligation 67 16 21 10 12 4 6 2 Expected return on plan assets (143) (36) (48) (22) (25) (7) (11) (5) Amortization of actuarial loss 34 7 11 5 6 2 3 2 Amortization of prior service credit (8) (2) (1) — — — — (2) Amortization of settlement charges 2 1 1 — — — — — Net periodic pension costs $ (7) $ (2) $ (4) $ (1) $ (2) $ — $ — $ (2) NON-QUALIFIED PENSION PLANS Net periodic pension costs for non-qualified pension plans were not material for the three months ended March 31, 2021, and 2020. OTHER POST-RETIREMENT BENEFIT PLANS Net periodic costs for OPEB plans were not material for the three months ended March 31, 2021, and 2020.

Income Taxes

Income Taxes	3 Months Ended
Income Taxes	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES EFFECTIVE TAX RATES The ETRs from continuing operations for each of the Duke Energy Registrants are included in the following table. Three Months Ended March 31, 2021 2020 Duke Energy 8.2 % 13.3 % Duke Energy Carolinas 6.9 % 16.1 % Progress Energy 12.9 % 17.5 % Duke Energy Progress 8.3 % 17.1 % Duke Energy Florida 19.3 % 20.0 % Duke Energy Ohio 13.3 % 17.7 % Duke Energy Indiana 17.6 % 20.8 % Piedmont 11.4 % 10.1 % The decrease in the ETR for Duke Energy for the three months ended March 31, 2021, was primarily due to an increase in the amortization of excess deferred taxes. The decrease in the ETR for Duke Energy Carolinas for the three months ended March 31, 2021, was primarily due to an increase in the amortization of excess deferred taxes. The decrease in the ETR for Progress Energy for the three months ended March 31, 2021, was primarily due to an increase in the amortization of excess deferred taxes. The decrease in the ETR for Duke Energy Progress for the three months ended March 31, 2021, was primarily due to an increase in the amortization of excess deferred taxes. The decrease in the ETR for Duke Energy Ohio for the three months ended March 31, 2021, was primarily due to an increase in amortization of excess deferred taxes. The decrease in the ETR for Duke Energy Indiana for the three months ended March 31, 2021, was primarily due to an increase in the amortization of excess deferred taxes.

Subsequent Events

Subsequent Events	3 Months Ended
Subsequent Events	Mar. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTSFor information on subsequent events related to regulatory matters, commitments and contingencies and debt and credit facilities, see Notes 3, 4 and 5.

Organization and Basis of Pre_2

Organization and Basis of Presentation (Policy)	3 Months Ended
Organization and Basis of Presentation (Policy)	Mar. 31, 2021
Policy Text Block [Line Items]
Basis of Presentation	BASIS OF PRESENTATION These Condensed Consolidated Financial Statements have been prepared in accordance with GAAP for interim financial information and with the instructions to Form 10-Q and Regulation S-X. Accordingly, these Condensed Consolidated Financial Statements do not include all information and notes required by GAAP for annual financial statements and should be read in conjunction with the Consolidated Financial Statements in the Duke Energy Registrants’ combined Annual Report on Form 10-K for the year ended December 31, 2020. The information in these combined notes relates to each of the Duke Energy Registrants as noted in the Index to Combined Notes to Condensed Consolidated Financial Statements. However, none of the registrants make any representations as to information related solely to Duke Energy or the subsidiaries of Duke Energy other than itself. These Condensed Consolidated Financial Statements, in the opinion of the respective companies’ management, reflect all normal recurring adjustments necessary to fairly present the financial position and results of operations of each of the Duke Energy Registrants. Amounts reported in Duke Energy’s interim Condensed Consolidated Statements of Operations and each of the Subsidiary Registrants’ interim Condensed Consolidated Statements of Operations and Comprehensive Income are not necessarily indicative of amounts expected for the respective annual periods due to effects of seasonal temperature variations on energy consumption, regulatory rulings, timing of maintenance on electric generating units, changes in mark-to-market valuations, changing commodity prices and other factors. In preparing financial statements that conform to GAAP, management must make estimates and assumptions that affect the reported amounts of assets and liabilities, the reported amounts of revenues and expenses and the disclosure of contingent assets and liabilities at the date of the financial statements. Actual results could differ from those estimates.
Basis of Consolidation and Noncontrolling Interest	BASIS OF CONSOLIDATION These Condensed Consolidated Financial Statements include, after eliminating intercompany transactions and balances, the accounts of the Duke Energy Registrants and subsidiaries or VIEs where the respective Duke Energy Registrants have control. See Note 11 for additional information on VIEs. These Condensed Consolidated Financial Statements also reflect the Duke Energy Registrants’ proportionate share of certain jointly owned generation and transmission facilities. NONCONTROLLING INTEREST Duke Energy maintains a controlling financial interest in certain less than wholly owned nonregulated subsidiaries. As a result, Duke Energy consolidates these subsidiaries and presents the third-party investors' portion of Duke Energy's net income (loss), net assets and comprehensive income (loss) as noncontrolling interest. Noncontrolling interest is included as a component of equity on the Condensed Consolidated Balance Sheet. Several operating agreements of Duke Energy's subsidiaries with noncontrolling interest are subject to allocations of earnings, tax attributes and cash flows in accordance with contractual agreements that vary throughout the lives of the subsidiaries. Therefore, Duke Energy and the other investors' (the owners) interests in the subsidiaries are not fixed, and the subsidiaries apply the Hypothetical Liquidation at Book Value (HLBV) method in allocating income or loss and other comprehensive income or loss (all measured on a pretax basis) to the owners. The HLBV method measures the amounts that each owner would hypothetically claim at each balance sheet reporting date, including tax benefits realized by the owners over the IRS recapture period, upon a hypothetical liquidation of the subsidiary at the net book value of its underlying assets. The change in the amount that each owner would hypothetically receive at the reporting date compared to the amount it would have received on the previous reporting date represents the amount of income or loss allocated to each owner for the reporting period.
Cash, Cash Equivalents, and Restricted Cash	CASH, CASH EQUIVALENTS AND RESTRICTED CASHDuke Energy, Progress Energy and Duke Energy Florida have restricted cash balances related primarily to collateral assets, escrow deposits and VIEs. See Notes 9 and 11 for additional information. Restricted cash amounts are included in Other within Current Assets and Other Noncurrent Assets on the Condensed Consolidated Balance Sheets.
New Accounting Standards	NEW ACCOUNTING STANDARDS No new accounting standards were adopted by the Duke Energy Registrants in 2021, but the following accounting standard was adopted by the Duke Energy Registrants in 2020. Current Expected Credit Losses. In June 2016, the Financial Accounting Standards Board (FASB) issued new accounting guidance for credit losses. Duke Energy adopted the new accounting guidance for credit losses effective January 1, 2020, using the modified retrospective method of adoption, which does not require restatement of prior year results. Duke Energy did not adopt any practical expedients. Duke Energy recognizes allowances for credit losses based on management's estimate of losses expected to be incurred over the lives of certain assets or guarantees. Management monitors credit quality, changes in expected credit losses and the appropriateness of the allowance for credit losses on a forward-looking basis. Management reviews the risk of loss periodically as part of the existing assessment of collectability of receivables. Duke Energy reviews the credit quality of its counterparties as part of its regular risk management process and requires credit enhancements, such as deposits or letters of credit, as appropriate and as allowed by regulators. Duke Energy recorded cumulative effects of changes in accounting principles related to the adoption of new credit loss standard, for allowances for credit losses of trade and other receivables, insurance receivables and financial guarantees. These amounts are included in the Condensed Consolidated Balance Sheets in Receivables, Receivables of VIEs, Other Noncurrent Assets and Other Noncurrent Liabilities. See Notes 4 and 12 for more information. Duke Energy recorded an adjustment for the cumulative effect of a change in accounting principle due to the adoption of this standard on January 1, 2020, as shown in the table below: January 1, 2020 Duke Duke Duke Duke Energy Progress Energy Energy (in millions) Energy Carolinas Energy Progress Florida Piedmont Total pretax impact to Retained Earnings $ 120 $ 16 $ 2 $ 1 $ 1 $ 1 The following new accounting standard has been issued but not yet adopted by the Duke Energy Registrants as of March 31, 2021. Reference Rate Reform. In March 2020, the FASB issued new accounting guidance for reference rate reform. This guidance is elective and provides expedients to facilitate financial reporting for the anticipated transition away from the London Inter-bank Offered Rate (LIBOR) and other interbank reference rates by the end of 2021. The optional expedients are effective for modification of existing contracts or new arrangements executed between March 12, 2020, through December 31, 2022. Duke Energy has variable-rate debt and manages interest rate risk by entering into financial contracts including interest rate swaps that are generally indexed to LIBOR. Impacted financial arrangements extending beyond 2021 may require contractual amendment or termination to fully adapt to a post-LIBOR environment. Duke Energy is assessing these financial arrangements and is evaluating the use of optional expedients outlined in the new accounting guidance. Alternative index provisions are also being assessed and incorporated into new financial arrangements that extend beyond 2021. The full outcome of the transition away from LIBOR cannot be determined at this time, but is not expected to have a material impact on the financial statements.
Environmental Costs	Liabilities are recorded when losses become probable and are reasonably estimable.Costs are typically expensed as Operation, maintenance and other on the Condensed Consolidated Statements of Operations unless regulatory recovery of the costs is deemed probable.
Derivatives	Duke Energy’s interest rate swaps for its regulated operations employ regulatory accounting. With regulatory accounting, the mark-to-market gains or losses on the swaps are deferred as regulatory liabilities or regulatory assets, respectively. Regulatory assets and liabilities are amortized consistent with the treatment of the related costs in the ratemaking process. The accrual of interest on the swaps is recorded as Interest Expense on the Duke Energy Registrant's Condensed Consolidated Statements of Operations and Comprehensive Income. Cash Flow Hedges For derivatives designated as hedging the exposure to variable cash flows of a future transaction, referred to as a cash flow hedge, the derivative's gain or loss is initially reported as a component of other comprehensive income and subsequently reclassified into earnings once the future transaction impacts earnings. Gains and losses reclassified out of accumulated other comprehensive loss for the three months ended March 31, 2021, and 2020, were not material. Duke Energy’s commodity derivatives designated as hedges include long-term electricity sales in the Commercial Renewables segment. Undesignated Contracts For the Subsidiary Registrants, bulk power electricity and natural gas purchases flow through fuel adjustment clauses, formula-based contracts or other cost-sharing mechanisms. Differences between the costs included in rates and the incurred costs, including undesignated derivative contracts, are largely deferred as regulatory assets or regulatory liabilities. Piedmont policies allow for the use of financial instruments to hedge commodity price risks. The strategy and objective of these hedging programs are to use the financial instruments to reduce natural gas costs volatility for customers.
Investments	As a result, the ability to hold investments in unrealized loss positions is outside the control of the Duke Energy Registrants. Accordingly, all unrealized losses associated with debt securities within the Investment Trusts are recognized immediately and deferred to regulatory accounts where appropriate.Unrealized gains and losses on all other AFS securities are included in other comprehensive income until realized, unless it is determined the carrying value of an investment has a credit loss. The Duke Energy Registrants analyze all investment holdings each reporting period to determine whether a decline in fair value is related to a credit loss. If a credit loss exists, the unrealized credit loss is included in earnings.
Revenue from Contract with Customer	Duke Energy earns substantially all of its revenues through its reportable segments, Electric Utilities and Infrastructure, Gas Utilities and Infrastructure and Commercial Renewables.
Earnings Per Share	Basic EPS is computed by dividing net income available to Duke Energy common stockholders, as adjusted for distributed and undistributed earnings allocated to participating securities and accumulated preferred dividends, by the weighted average number of common shares outstanding during the period. Diluted EPS is computed by dividing net income available to Duke Energy common stockholders, as adjusted for distributed and undistributed earnings allocated to participating securities and accumulated preferred dividends, by the diluted weighted average number of common shares outstanding during the period. Diluted EPS reflects the potential dilution that could occur if securities or other agreements to issue common stock, such as equity forward sale agreements, were exercised or settled. Duke Energy’s participating securities are restricted stock units that are entitled to dividends declared on Duke Energy common stock during the restricted stock unit’s vesting periods. Dividends declared on preferred stock are recorded on the Condensed Consolidated Statements of Operations as a reduction of net income to arrive at net income available to Duke Energy common stockholders. Dividends accumulated on preferred stock are an adjustment to net income used in the calculation of basic and diluted EPS.

Organization and Basis of Pre_3

Organization and Basis of Presentation (Tables)	3 Months Ended
Organization and Basis of Presentation (Tables)	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Cash Received and Allocated Losses from Subsidiaries, Noncontrolling Interest	The following table presents cash received for the sale of noncontrolling interest and allocated losses to noncontrolling interest for the three months ended March 31, 2021, and 2020. Three Months Ended March 31, (in millions) 2021 2020 Noncontrolling Interest Capital Contributions Cash received for the sale of noncontrolling interest to tax equity members $ 303 $ 103 Cash received for the sale of noncontrolling interest to pro rata share members — — Total Noncontrolling Interest Capital Contributions 303 103 Noncontrolling Interest Allocation of Income Allocated losses to noncontrolling tax equity members utilizing the HLBV method 43 49 Allocated losses (gains) to noncontrolling members based on pro rata shares of ownership 8 (1) Total Noncontrolling Interest Allocated Losses $ 51 $ 48
Schedule of Cash, Cash Equivalents and Restricted Cash	The following table presents the components of cash, cash equivalents and restricted cash included in the Condensed Consolidated Balance Sheets. March 31, 2021 December 31, 2020 Duke Duke Duke Progress Energy Duke Progress Energy Energy Energy Florida Energy Energy Florida Current Assets Cash and cash equivalents $ 379 $ 74 $ 22 $ 259 $ 59 $ 11 Other 210 13 13 194 39 39 Other Noncurrent Assets Other 103 102 — 103 102 — Total cash, cash equivalents and restricted cash $ 692 $ 189 $ 35 $ 556 $ 200 $ 50
Schedule of Utility Inventory	The components of inventory are presented in the tables below. March 31, 2021 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Materials and supplies $ 2,365 $ 816 $ 1,011 $ 680 $ 332 $ 77 $ 313 $ 11 Coal 464 170 160 101 59 12 122 — Natural gas, oil and other fuel 247 35 165 101 64 19 1 26 Total inventory $ 3,076 $ 1,021 $ 1,336 $ 882 $ 455 $ 108 $ 436 $ 37 December 31, 2020 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Materials and supplies $ 2,312 $ 785 $ 999 $ 673 $ 325 $ 78 $ 307 $ 12 Coal 561 186 193 131 63 16 165 — Natural gas, oil and other fuel 294 39 183 107 76 16 1 56 Total inventory $ 3,167 $ 1,010 $ 1,375 $ 911 $ 464 $ 110 $ 473 $ 68
Schedule of New Accounting Pronouncements	Duke Energy recorded an adjustment for the cumulative effect of a change in accounting principle due to the adoption of this standard on January 1, 2020, as shown in the table below: January 1, 2020 Duke Duke Duke Duke Energy Progress Energy Energy (in millions) Energy Carolinas Energy Progress Florida Piedmont Total pretax impact to Retained Earnings $ 120 $ 16 $ 2 $ 1 $ 1 $ 1

Business Segments (Tables)

Business Segments (Tables)	3 Months Ended
Business Segments (Tables)	Mar. 31, 2021
Segment Reporting Information [Line Items]
Business Segment Data	Business segment information is presented in the following tables. Segment assets presented exclude intercompany assets. Three Months Ended March 31, 2021 Electric Gas Total Utilities and Utilities and Commercial Reportable (in millions) Infrastructure Infrastructure Renewables Segments Other Eliminations Total Unaffiliated revenues $ 5,273 $ 752 $ 119 $ 6,144 $ 6 $ — $ 6,150 Intersegment revenues 8 23 — 31 20 (51) — Total revenues $ 5,281 $ 775 $ 119 $ 6,175 $ 26 $ (51) $ 6,150 Segment income (loss) (a) $ 820 $ 245 $ 27 $ 1,092 $ (139) $ — $ 953 Less: Noncontrolling interests 51 Add: Preferred stock dividend 39 Net Income $ 941 Segment assets $ 138,734 $ 14,139 $ 6,894 $ 159,767 $ 3,710 $ (12) $ 163,465 Three Months Ended March 31, 2020 Electric Gas Total Utilities and Utilities and Commercial Reportable (in millions) Infrastructure Infrastructure Renewables Segments Other Eliminations Total Unaffiliated revenues $ 5,174 $ 640 $ 129 $ 5,943 $ 6 $ — $ 5,949 Intersegment revenues 9 24 — 33 17 (50) — Total revenues $ 5,183 $ 664 $ 129 $ 5,976 $ 23 $ (50) $ 5,949 Segment income (loss) (b) $ 705 $ 249 $ 57 $ 1,011 $ (112) $ — $ 899 Less: Noncontrolling interests 48 Add: Preferred stock dividend 39 Net Income $ 890 (a) Commercial Renewables includes a $35 million loss related to Texas Storm Uri, of which $8 million is recorded within Nonregulated electric and other revenues, $2 million within Operations, maintenance and other, $29 million within Equity in (losses) earnings of unconsolidated affiliates and $12 million within Loss Attributable to Noncontrolling Interests on the Condensed Consolidated Statements of Operations. See Note 4 for additional information. G as Utilities and Infrastructure includes $6 million, recorded within Equity in (losses) earnings of unconsolidated affiliates on the Condensed Consolidated Statements of Operations, related to gas pipeline investments. See Note 3 for additional information. (b) Other includes a $98 million reversal, recorded within Operations, maintenance and other on the Condensed Consolidated Statements of Operations, related to 2018 severance costs due to the partial settlement of the Duke Energy Carolinas 2019 North Carolina rate case. See Note 3 for additional information.
Duke Energy Ohio
Segment Reporting Information [Line Items]
Business Segment Data	Three Months Ended March 31, 2021 Electric Gas Total Utilities and Utilities and Reportable (in millions) Infrastructure Infrastructure Segments Other Eliminations Total Total revenues $ 363 $ 169 $ 532 $ — $ — $ 532 Segment income/Net income $ 50 $ 43 $ 93 $ (2) $ — $ 91 Segment assets $ 6,544 $ 3,575 $ 10,119 $ 29 $ (7) $ 10,141 Three Months Ended March 31, 2020 Electric Gas Total Utilities and Utilities and Reportable (in millions) Infrastructure Infrastructure Segments Other Total Total revenues $ 346 $ 152 $ 498 $ — $ 498 Segment income/Net income $ 30 $ 36 $ 66 $ (1) $ 65

Regulatory Matters (Tables)

Regulatory Matters (Tables)	3 Months Ended
Regulatory Matters (Tables)	Mar. 31, 2021
Regulated Operations [Abstract]
Schedule of Potential Plant Retirements	The table below contains the net carrying value of generating facilities planned for retirement or included in recent integrated resource plans (IRPs) as evaluated for potential retirement. Dollar amounts in the table below are included in Net property, plant and equipment on the Condensed Consolidated Balance Sheets as of March 31, 2021, and exclude capitalized asset retirement costs. Remaining Net Capacity Book Value (in MW) (in millions) Duke Energy Carolinas Allen Steam Station Units 1-2 (a) 334 $ 21 Allen Steam Station Units 4-5 (b) 526 388 Cliffside Unit 5 (b) 546 343 Duke Energy Progress Mayo Unit 1 (b) 746 660 Roxboro Units 3-4 (b) 1,409 478 Duke Energy Florida Crystal River Units 4-5 (c) 1,430 1,683 Duke Energy Indiana Gallagher Units 2 and 4 (d) 280 91 Gibson Units 1-5 (e) 2,845 1,834 Cayuga Units 1-2 (e) 1,005 755 Total Duke Energy 9,121 $ 6,253 (a) As part of the 2015 resolution of a lawsuit involving alleged New Source Review violations, Duke Energy Carolinas must retire Allen Steam Station Units 1 through 3 by December 31, 2024. The long-term energy options considered in the IRP could result in retirement of these units earlier than their current estimated useful lives. Unit 3 with a capacity of 270 MW and a net book value of $26 million at December 31, 2020, was retired in March 2021. (b) These units are included in the IRP filed by Duke Energy Carolinas and Duke Energy Progress in North Carolina and South Carolina on September 1, 2020. The long-term energy options considered in the IRP could result in retirement of these units earlier than their current estimated useful lives. In 2019, Duke Energy Carolinas and Duke Energy Progress filed North Carolina rate cases that included depreciation studies that accelerate end-of-life dates for these plants. NCUC issued orders in the 2019 rate cases of Duke Energy Carolinas and Duke Energy Progress on March 31, 2021, and April 16, 2021, respectively, in which the proposals to shorten the remaining depreciable lives of these units were denied, while indicating the IRP proceeding was the appropriate proceeding for the review of generating plant retirements. (c) On January 14, 2021, Duke Energy Florida filed a settlement agreement with the FPSC, which proposed depreciation rates reflecting retirement dates for Duke Energy Florida's last two coal-fired generating facilities, Crystal River Units 4-5, eight years ahead of schedule in 2034 rather than in 2042. The settlement was approved by the FPSC on May 4, 2021. (d) Duke Energy Indiana committed to either retire or stop burning coal at Gallagher Units 2 and 4 by December 31, 2022, as part of the 2016 settlement of Edwardsport IGCC matters. In February 2021, upon approval by MISO of a new retirement date, Duke Energy Indiana determined it would modify the retirement date to June 1, 2021. (e) On July 1, 2019, Duke Energy Indiana filed its 2018 IRP with the IURC. The 2018 IRP included scenarios evaluating the potential retirement of coal-fired generating units at Gibson and Cayuga. The rate case filed July 2, 2019, included proposed depreciation rates reflecting retirement dates from 2026 to 2038. The depreciation rates reflecting these updated retirement dates were approved by the IURC as part of the rate case order issued on June 29, 2020.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
Commitments and Contingencies (Tables)	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Schedule of Reserves	The following table contains information regarding reserves for probable and estimable costs related to the various environmental sites. These reserves are recorded in Accounts Payable within Current Liabilities and Other within Other Noncurrent Liabilities on the Condensed Consolidated Balance Sheets. (in millions) March 31, 2021 December 31, 2020 Reserves for Environmental Remediation Duke Energy $ 74 $ 75 Duke Energy Carolinas 18 19 Progress Energy 18 19 Duke Energy Progress 6 6 Duke Energy Florida 12 12 Duke Energy Ohio 21 22 Duke Energy Indiana 5 6 Piedmont 11 10 The table below presents recorded reserves based on management’s best estimate of probable loss for legal matters, excluding asbestos-related reserves discussed above. Reserves are classified on the Condensed Consolidated Balance Sheets in Other within Other Noncurrent Liabilities and Other within Current Liabilities. The reasonably possible range of loss in excess of recorded reserves is not material, other than as described above. (in millions) March 31, 2021 December 31, 2020 Reserves for Legal Matters Duke Energy $ 65 $ 68 Duke Energy Carolinas 3 2 Progress Energy 57 61 Duke Energy Progress 11 13 Duke Energy Florida 26 28 Piedmont 1 1
Schedule of Additional Possible Losses in Excess of Recorded Environmental Reserves	Additional losses in excess of recorded reserves that could be incurred for the stages of investigation, remediation and monitoring for environmental sites that have been evaluated at this time are not material except as presented in the table below. (in millions) Duke Energy $ 20 Duke Energy Carolinas 12 Duke Energy Ohio 4

Debt and Credit Facilities (Tab

Debt and Credit Facilities (Tables)	3 Months Ended
Debt and Credit Facilities (Tables)	Mar. 31, 2021
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	The following table summarizes significant debt issuances (in millions). Three Months Ended March 31, 2021 Duke Duke Duke Duke Duke Duke Maturity Interest Duke Energy Energy Energy Energy Energy Energy Issuance Date Date Rate Energy (Parent) Carolinas Progress Florida Ohio Indiana Piedmont Unsecured Debt March 2021 (a) Mar 2031 2.500 % $ 350 $ — $ — $ — $ — $ — $ — $ 350 Total issuances $ 350 $ — $ — $ — $ — $ — $ — $ 350 (a) Debt issued to repay at maturity $160 million senior unsecured notes due June 2021, pay down short-term debt and for general corporate purposes. The following table shows the significant components of Current maturities of long-term debt on the Condensed Consolidated Balance Sheets. The Duke Energy Registrants currently anticipate satisfying these obligations with cash on hand and proceeds from additional borrowings. (in millions) Maturity Date Interest Rate March 31, 2021 Unsecured Debt Duke Energy (Parent) May 2021 0.698 % (a) 500 Piedmont June 2021 4.240 % 160 Duke Energy (Parent) September 2021 3.550 % 500 Duke Energy (Parent) September 2021 1.800 % 750 Duke Energy Florida November 2021 0.441 % (a) 200 Duke Energy Progress February 2022 0.369 % (a) 700 Duke Energy (Parent) March 2022 3.227 % 300 Duke Energy (Parent) March 2022 0.827 % (a) 300 First Mortgage Bonds Duke Energy Carolinas June 2021 3.900 % 500 Duke Energy Florida August 2021 3.100 % 300 Duke Energy Progress September 2021 3.000 % 500 Duke Energy Progress September 2021 8.625 % 100 Duke Energy Indiana January 2022 8.850 % 53 Other (b) 723 Current maturities of long-term debt $ 5,586 (a) Debt has a floating interest rate. (b) Includes finance lease obligations, amortizing debt, tax-exempt bonds with mandatory put options and small bullet maturities.
Schedule Of Line Of Credit Facilities	The table below includes the current borrowing sublimits and available capacity under these credit facilities. March 31, 2021 Duke Duke Duke Duke Duke Duke Duke Energy Energy Energy Energy Energy Energy (in millions) Energy (Parent) Carolinas Progress Florida Ohio Indiana Piedmont Facility size (a) $ 8,000 $ 2,650 $ 1,475 $ 1,250 $ 700 $ 625 $ 600 $ 700 Reduction to backstop issuances Commercial paper (b) (3,466) (1,781) (741) (292) (243) (259) (150) — Outstanding letters of credit (31) (25) (4) (2) — — — — Tax-exempt bonds (81) — — — — — (81) — Available capacity under the Master Credit Facility $ 4,422 $ 844 $ 730 $ 956 $ 457 $ 366 $ 369 $ 700 (a) Represents the sublimit of each borrower. March 31, 2021 (in millions) Facility size Amount drawn Duke Energy (Parent) Three (a) $ 1,000 $ 500

Goodwill (Tables)

Goodwill (Tables)	3 Months Ended
Goodwill (Tables)	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill By Reportable Operating Segment	The following table presents the goodwill by reportable segment included on Duke Energy's Condensed Consolidated Balance Sheets at March 31, 2021, and December 31, 2020. Electric Utilities Gas Utilities Commercial (in millions) and Infrastructure and Infrastructure Renewables Total Goodwill balance $ 17,379 $ 1,924 $ 122 $ 19,425 Accumulated impairment charges — — (122) (122) Goodwill, adjusted for accumulated impairment charges $ 17,379 $ 1,924 $ — $ 19,303

Related Party Transactions (Tab

Related Party Transactions (Tables)	3 Months Ended
Related Party Transactions (Tables)	Mar. 31, 2021
Related Party Transactions [Abstract]
Schedule of Related Party Transactions, Other Revenue and Expense	Material amounts related to transactions with related parties included on the Condensed Consolidated Statements of Operations and Comprehensive Income are presented in the following table. Three Months Ended March 31, (in millions) 2021 2020 Duke Energy Carolinas Corporate governance and shared service expenses (a) $ 203 $ 134 Indemnification coverages (b) 6 5 Joint Dispatch Agreement (JDA) revenue (c) 13 7 JDA expense (c) 40 24 Intercompany natural gas purchases (d) 14 6 Progress Energy Corporate governance and shared service expenses (a) $ 181 $ 146 Indemnification coverages (b) 10 9 JDA revenue (c) 40 24 JDA expense (c) 13 7 Intercompany natural gas purchases (d) 19 19 Duke Energy Progress Corporate governance and shared service expenses (a) $ 105 $ 75 Indemnification coverages (b) 5 4 JDA revenue (c) 40 24 JDA expense (c) 13 7 Intercompany natural gas purchases (d) 19 19 Duke Energy Florida Corporate governance and shared service expenses (a) $ 76 $ 71 Indemnification coverages (b) 5 5 Duke Energy Ohio Corporate governance and shared service expenses (a) $ 79 $ 84 Indemnification coverages (b) 1 1 Duke Energy Indiana Corporate governance and shared service expenses (a) $ 113 $ 106 Indemnification coverages (b) 2 2 Piedmont Corporate governance and shared service expenses (a) $ 33 $ 34 Indemnification coverages (b) 1 1 Intercompany natural gas sales (d) 33 25 Natural gas storage and transportation costs (e) 6 6 (a) The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, primarily related to human resources, employee benefits, information technology, legal and accounting fees, as well as other third-party costs. These amounts are primarily recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income. (b) The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income. (c) Duke Energy Carolinas and Duke Energy Progress participate in a JDA, which allows the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power and expenses from the purchase of power pursuant to the JDA are recorded in Operating Revenues and Fuel used in electric generation and purchased power, respectively, on the Condensed Consolidated Statements of Operations and Comprehensive Income. (d) Piedmont provides long-term natural gas delivery service to certain Duke Energy Carolinas and Duke Energy Progress natural gas-fired generation facilities. Piedmont records the sales in Operating revenues, and Duke Energy Carolinas and Duke Energy Progress record the related purchases as a component of Fuel used in electric generation and purchased power on their respective Condensed Consolidated Statements of Operations and Comprehensive Income. Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Carolinas Energy Progress Florida Ohio Indiana Piedmont March 31, 2021 Intercompany income tax receivable $ — $ 84 $ — $ 46 $ — $ — $ — Intercompany income tax payable 31 — 12 — 2 36 39 December 31, 2020 Intercompany income tax receivable $ — $ — $ — $ — $ — $ 9 $ 10 Intercompany income tax payable 31 33 46 35 2 — —

Derivatives and Hedging (Tables

Derivatives and Hedging (Tables)	3 Months Ended
Derivatives and Hedging (Tables)	Mar. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Notional Amounts of Outstanding Derivative Positions	The following table shows notional amounts of outstanding derivatives related to interest rate risk. March 31, 2021 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Cash flow hedges $ 1,630 $ — $ — $ — $ — $ — Undesignated contracts 1,731 400 1,250 750 500 27 Total notional amount (a) $ 3,361 $ 400 $ 1,250 $ 750 $ 500 $ 27 December 31, 2020 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Cash flow hedges $ 632 $ — $ — $ — $ — $ — Undesignated contracts 1,177 400 750 750 — 27 Total notional amount (a) $ 1,809 $ 400 $ 750 $ 750 $ — $ 27 (a) Duke Energy includes amounts related to consolidated VIEs of $631 million in cash flow hedges and $54 million in undesignated contracts as of March 31, 2021, and $632 million in cash flow hedges as of December 31, 2020. The tables below include volumes of outstanding commodity derivatives. Amounts disclosed represent the absolute value of notional volumes of commodity contracts excluding NPNS. The Duke Energy Registrants have netted contractual amounts where offsetting purchase and sale contracts exist with identical delivery locations and times of delivery. Where all commodity positions are perfectly offset, no quantities are shown. March 31, 2021 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy Carolinas Energy Progress Ohio Indiana Piedmont Electricity (GWh) (a) 16,259 — — — 1,325 4,214 — Natural gas (millions of dekatherms) 675 151 158 158 — 2 364 December 31, 2020 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy Carolinas Energy Progress Ohio Indiana Piedmont Electricity (GWh) (a) 35,409 — — — 2,559 10,802 — Natural gas (millions of dekatherms) 678 145 158 158 — 2 373 (a) Duke Energy includes 10,720 GWh and 22,048 GWh related to cash flow hedges as of March 31, 2021, and December 31, 2020, respectively.
Location And Fair Value Of Derivatives Recognized in the Condensed Consolidated Balance Sheets	The following tables show the fair value and balance sheet location of derivative instruments. Although derivatives subject to master netting arrangements are netted on the Condensed Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown. Derivative Assets March 31, 2021 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Commodity Contracts Not Designated as Hedging Instruments Current $ 32 $ 17 $ 12 $ 12 $ — $ — $ 2 $ 1 Noncurrent 14 7 7 7 — — — — Total Derivative Assets – Commodity Contracts $ 46 $ 24 $ 19 $ 19 $ — $ — $ 2 $ 1 Interest Rate Contracts Designated as Hedging Instruments Current $ 31 $ — $ — $ — $ — $ — $ — $ — Not Designated as Hedging Instruments Current $ 129 $ 38 $ 84 $ 81 $ 3 $ — $ — $ — Total Derivative Assets – Interest Rate Contracts $ 160 $ 38 $ 84 $ 81 $ 3 $ — $ — $ — Total Derivative Assets $ 206 $ 62 $ 103 $ 100 $ 3 $ — $ 2 $ 1 Derivative Liabilities March 31, 2021 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Commodity Contracts Designated as Hedging Instruments Current $ 19 $ — $ — $ — $ — $ — $ — — Noncurrent 109 — — — — — — — Not Designated as Hedging Instruments Current $ 19 $ — $ — $ — $ — $ — $ — $ 19 Noncurrent 154 — 25 9 — — — 129 Total Derivative Liabilities – Commodity Contracts $ 301 $ — $ 25 $ 9 $ — $ — $ — $ 148 Interest Rate Contracts Designated as Hedging Instruments Current $ 15 $ — $ — $ — $ — $ — $ — $ — Noncurrent 25 — — — — — — — Not Designated as Hedging Instruments Current 4 — 3 — 3 1 — — Noncurrent 4 — — — — 4 — — Total Derivative Liabilities – Interest Rate Contracts $ 48 $ — $ 3 $ — $ 3 $ 5 $ — $ — Total Derivative Liabilities $ 349 $ — $ 28 $ 9 $ 3 $ 5 $ — $ 148 Derivative Assets December 31, 2020 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Commodity Contracts Not Designated as Hedging Instruments Current $ 30 $ 14 $ 9 $ 9 $ — $ 1 $ 6 $ 1 Noncurrent 13 6 6 6 — — — — Total Derivative Assets – Commodity Contracts $ 43 $ 20 $ 15 $ 15 $ — $ 1 $ 6 $ 1 Interest Rate Contracts Not Designated as Hedging Instruments Current $ 18 $ — $ 18 $ 18 $ — $ — $ — $ — Total Derivative Assets – Interest Rate Contracts $ 18 $ — $ 18 $ 18 $ — $ — $ — $ — Total Derivative Assets $ 61 $ 20 $ 33 $ 33 $ — $ 1 $ 6 $ 1 Derivative Liabilities December 31, 2020 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Commodity Contracts Designated as Hedging Instruments Current $ 14 $ — $ — $ — $ — $ — $ — $ — Noncurrent 70 — — — — — — — Not Designated as Hedging Instruments Current $ 30 $ 13 $ 2 $ 2 $ — $ — $ 1 $ 15 Noncurrent 137 3 27 12 — — — 107 Total Derivative Liabilities – Commodity Contracts $ 251 $ 16 $ 29 $ 14 $ — $ — $ 1 $ 122 Interest Rate Contracts Designated as Hedging Instruments Current $ 15 $ — $ — $ — $ — $ — $ — $ — Noncurrent 48 — — — — — — — Not Designated as Hedging Instruments Current 5 4 — — — 1 — — Noncurrent 5 — — — — 5 — — Total Derivative Liabilities – Interest Rate Contracts $ 73 $ 4 $ — $ — $ — $ 6 $ — $ — Total Derivative Liabilities $ 324 $ 20 $ 29 $ 14 $ — $ 6 $ 1 $ 122
Offsetting Assets	The following tables present the line items on the Condensed Consolidated Balance Sheets where derivatives are reported. Substantially all of Duke Energy's outstanding derivative contracts are subject to enforceable master netting arrangements. The gross amounts offset in the tables below show the effect of these netting arrangements on financial position, and include collateral posted to offset the net position. The amounts shown are calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below. Derivative Assets March 31, 2021 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Current Gross amounts recognized $ 192 $ 55 $ 96 $ 93 $ 3 $ — $ 2 $ 1 Gross amounts offset — — — — — — — — Net amounts presented in Current Assets: Other $ 192 $ 55 $ 96 $ 93 $ 3 $ — $ 2 $ 1 Noncurrent Gross amounts recognized $ 14 $ 7 $ 7 $ 7 $ — $ — $ — $ — Gross amounts offset (4) — (4) (4) — — — — Net amounts presented in Other Noncurrent Assets: Other $ 10 $ 7 $ 3 $ 3 $ — $ — $ — $ — Derivative Liabilities March 31, 2021 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Current Gross amounts recognized $ 57 $ — $ 3 $ — $ 3 $ 1 $ — $ 19 Gross amounts offset — — — — — — — — Net amounts presented in Current Liabilities: Other $ 57 $ — $ 3 $ — $ 3 $ 1 $ — $ 19 Noncurrent Gross amounts recognized $ 292 $ — $ 25 $ 9 $ — $ 4 $ — $ 129 Gross amounts offset (4) — (4) (4) — — — — Net amounts presented in Other Noncurrent Liabilities: Other $ 288 $ — $ 21 $ 5 $ — $ 4 $ — $ 129 Derivative Assets December 31, 2020 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Current Gross amounts recognized $ 48 $ 14 $ 27 $ 27 $ — $ 1 $ 6 $ 1 Gross amounts offset (3) (2) (2) (2) — — — — Net amounts presented in Current Assets: Other $ 45 $ 12 $ 25 $ 25 $ — $ 1 $ 6 $ 1 Noncurrent Gross amounts recognized $ 13 $ 6 $ 6 $ 6 $ — $ — $ — $ — Gross amounts offset (5) (1) (4) (4) — — — — Net amounts presented in Other Noncurrent Assets: Other $ 8 $ 5 $ 2 $ 2 $ — $ — $ — $ — Derivative Liabilities December 31, 2020 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Current Gross amounts recognized $ 64 $ 17 $ 2 $ 2 $ — $ 1 $ 1 $ 15 Gross amounts offset (3) (2) (2) (2) — — — — Net amounts presented in Current Liabilities: Other $ 61 $ 15 $ — $ — $ — $ 1 $ 1 $ 15 Noncurrent Gross amounts recognized $ 260 $ 3 $ 27 $ 12 $ — $ 5 $ — $ 107 Gross amounts offset (5) (1) (4) (4) — — — — Net amounts presented in Other Noncurrent Liabilities: Other $ 255 $ 2 $ 23 $ 8 $ — $ 5 $ — $ 107
Offsetting Liabilities	The following tables present the line items on the Condensed Consolidated Balance Sheets where derivatives are reported. Substantially all of Duke Energy's outstanding derivative contracts are subject to enforceable master netting arrangements. The gross amounts offset in the tables below show the effect of these netting arrangements on financial position, and include collateral posted to offset the net position. The amounts shown are calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below. Derivative Assets March 31, 2021 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Current Gross amounts recognized $ 192 $ 55 $ 96 $ 93 $ 3 $ — $ 2 $ 1 Gross amounts offset — — — — — — — — Net amounts presented in Current Assets: Other $ 192 $ 55 $ 96 $ 93 $ 3 $ — $ 2 $ 1 Noncurrent Gross amounts recognized $ 14 $ 7 $ 7 $ 7 $ — $ — $ — $ — Gross amounts offset (4) — (4) (4) — — — — Net amounts presented in Other Noncurrent Assets: Other $ 10 $ 7 $ 3 $ 3 $ — $ — $ — $ — Derivative Liabilities March 31, 2021 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Current Gross amounts recognized $ 57 $ — $ 3 $ — $ 3 $ 1 $ — $ 19 Gross amounts offset — — — — — — — — Net amounts presented in Current Liabilities: Other $ 57 $ — $ 3 $ — $ 3 $ 1 $ — $ 19 Noncurrent Gross amounts recognized $ 292 $ — $ 25 $ 9 $ — $ 4 $ — $ 129 Gross amounts offset (4) — (4) (4) — — — — Net amounts presented in Other Noncurrent Liabilities: Other $ 288 $ — $ 21 $ 5 $ — $ 4 $ — $ 129 Derivative Assets December 31, 2020 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Current Gross amounts recognized $ 48 $ 14 $ 27 $ 27 $ — $ 1 $ 6 $ 1 Gross amounts offset (3) (2) (2) (2) — — — — Net amounts presented in Current Assets: Other $ 45 $ 12 $ 25 $ 25 $ — $ 1 $ 6 $ 1 Noncurrent Gross amounts recognized $ 13 $ 6 $ 6 $ 6 $ — $ — $ — $ — Gross amounts offset (5) (1) (4) (4) — — — — Net amounts presented in Other Noncurrent Assets: Other $ 8 $ 5 $ 2 $ 2 $ — $ — $ — $ — Derivative Liabilities December 31, 2020 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Current Gross amounts recognized $ 64 $ 17 $ 2 $ 2 $ — $ 1 $ 1 $ 15 Gross amounts offset (3) (2) (2) (2) — — — — Net amounts presented in Current Liabilities: Other $ 61 $ 15 $ — $ — $ — $ 1 $ 1 $ 15 Noncurrent Gross amounts recognized $ 260 $ 3 $ 27 $ 12 $ — $ 5 $ — $ 107 Gross amounts offset (5) (1) (4) (4) — — — — Net amounts presented in Other Noncurrent Liabilities: Other $ 255 $ 2 $ 23 $ 8 $ — $ 5 $ — $ 107

Investments in Debt and Equit_2

Investments in Debt and Equity Securities (Tables)	3 Months Ended
Investments in Debt and Equity Securities (Tables)	Mar. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading, and Equity Securities, FV-NI	The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS. March 31, 2021 December 31, 2020 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses Value Gains Losses Value NDTF Cash and cash equivalents $ — $ — $ 193 $ — $ — $ 177 Equity securities 4,363 47 6,379 4,138 54 6,235 Corporate debt securities 38 8 793 76 1 806 Municipal bonds 13 1 299 22 — 370 U.S. government bonds 31 18 1,559 51 — 1,361 Other debt securities 5 — 184 8 — 180 Total NDTF Investments $ 4,450 $ 74 $ 9,407 $ 4,295 $ 55 $ 9,129 Other Investments Cash and cash equivalents $ — $ — $ 222 $ — $ — $ 127 Equity securities 86 — 154 79 — 146 Corporate debt securities 2 — 109 8 — 110 Municipal bonds 3 1 77 5 — 86 U.S. government bonds — 1 55 — — 42 Other debt securities — 1 36 — — 47 Total Other Investments $ 91 $ 3 $ 653 $ 92 $ — $ 558 Total Investments $ 4,541 $ 77 $ 10,060 $ 4,387 $ 55 $ 9,687
Debt Securities, Available-for-sale	The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS. March 31, 2021 December 31, 2020 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses Value Gains Losses Value NDTF Cash and cash equivalents $ — $ — $ 193 $ — $ — $ 177 Equity securities 4,363 47 6,379 4,138 54 6,235 Corporate debt securities 38 8 793 76 1 806 Municipal bonds 13 1 299 22 — 370 U.S. government bonds 31 18 1,559 51 — 1,361 Other debt securities 5 — 184 8 — 180 Total NDTF Investments $ 4,450 $ 74 $ 9,407 $ 4,295 $ 55 $ 9,129 Other Investments Cash and cash equivalents $ — $ — $ 222 $ — $ — $ 127 Equity securities 86 — 154 79 — 146 Corporate debt securities 2 — 109 8 — 110 Municipal bonds 3 1 77 5 — 86 U.S. government bonds — 1 55 — — 42 Other debt securities — 1 36 — — 47 Total Other Investments $ 91 $ 3 $ 653 $ 92 $ — $ 558 Total Investments $ 4,541 $ 77 $ 10,060 $ 4,387 $ 55 $ 9,687
Schedule of Realized Gain (Loss)	Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2021, and 2020, were as follows. Three Months Ended (in millions) March 31, 2021 March 31, 2020 FV-NI: Realized gains $ 140 $ 23 Realized losses 23 65 AFS: Realized gains 18 20 Realized losses 13 6
Investments Classified by Contractual Maturity Date	The table below summarizes the maturity date for debt securities. March 31, 2021 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Indiana Due in one year or less $ 152 $ 7 $ 116 $ 18 $ 98 $ 5 Due after one through five years 1,013 375 579 267 312 18 Due after five through 10 years 693 310 289 217 72 9 Due after 10 years 1,254 652 533 501 32 13 Total $ 3,112 $ 1,344 $ 1,517 $ 1,003 $ 514 $ 45
Duke Energy Carolinas
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading, and Equity Securities, FV-NI	The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS. March 31, 2021 December 31, 2020 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses Value Gains Losses Value NDTF Cash and cash equivalents $ — $ — $ 63 $ — $ — $ 30 Equity securities 2,531 23 3,738 2,442 23 3,685 Corporate debt securities 23 5 475 49 1 510 Municipal bonds — — 22 6 — 91 U.S. government bonds 16 9 669 25 — 475 Other debt securities 4 — 178 7 — 174 Total NDTF Investments $ 2,574 $ 37 $ 5,145 $ 2,529 $ 24 $ 4,965
Debt Securities, Available-for-sale	The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS. March 31, 2021 December 31, 2020 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses Value Gains Losses Value NDTF Cash and cash equivalents $ — $ — $ 63 $ — $ — $ 30 Equity securities 2,531 23 3,738 2,442 23 3,685 Corporate debt securities 23 5 475 49 1 510 Municipal bonds — — 22 6 — 91 U.S. government bonds 16 9 669 25 — 475 Other debt securities 4 — 178 7 — 174 Total NDTF Investments $ 2,574 $ 37 $ 5,145 $ 2,529 $ 24 $ 4,965
Schedule of Realized Gain (Loss)	Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2021, and 2020, were as follows. Three Months Ended (in millions) March 31, 2021 March 31, 2020 FV-NI: Realized gains $ 128 $ 9 Realized losses 16 45 AFS: Realized gains 13 12 Realized losses 9 5
Progress Energy
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading, and Equity Securities, FV-NI	The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS. March 31, 2021 December 31, 2020 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses Value Gains Losses Value NDTF Cash and cash equivalents $ — $ — $ 130 $ — $ — $ 147 Equity securities 1,832 24 2,641 1,696 31 2,550 Corporate debt securities 15 3 318 27 — 296 Municipal bonds 13 1 277 16 — 279 U.S. government bonds 15 9 890 26 — 886 Other debt securities 1 — 6 1 — 6 Total NDTF Investments $ 1,876 $ 37 $ 4,262 $ 1,766 $ 31 $ 4,164 Other Investments Cash and cash equivalents $ — $ — $ 107 $ — $ — $ 106 Municipal bonds 2 — 26 3 — 26 Total Other Investments $ 2 $ — $ 133 $ 3 $ — $ 132 Total Investments $ 1,878 $ 37 $ 4,395 $ 1,769 $ 31 $ 4,296
Debt Securities, Available-for-sale	The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS. March 31, 2021 December 31, 2020 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses Value Gains Losses Value NDTF Cash and cash equivalents $ — $ — $ 130 $ — $ — $ 147 Equity securities 1,832 24 2,641 1,696 31 2,550 Corporate debt securities 15 3 318 27 — 296 Municipal bonds 13 1 277 16 — 279 U.S. government bonds 15 9 890 26 — 886 Other debt securities 1 — 6 1 — 6 Total NDTF Investments $ 1,876 $ 37 $ 4,262 $ 1,766 $ 31 $ 4,164 Other Investments Cash and cash equivalents $ — $ — $ 107 $ — $ — $ 106 Municipal bonds 2 — 26 3 — 26 Total Other Investments $ 2 $ — $ 133 $ 3 $ — $ 132 Total Investments $ 1,878 $ 37 $ 4,395 $ 1,769 $ 31 $ 4,296
Schedule of Realized Gain (Loss)	Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2021, and 2020, were as follows. Three Months Ended (in millions) March 31, 2021 March 31, 2020 FV-NI: Realized gains $ 12 $ 14 Realized losses 7 20 AFS: Realized gains 4 5 Realized losses 3 1
Duke Energy Progress
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading, and Equity Securities, FV-NI	The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS. March 31, 2021 December 31, 2020 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses Value Gains Losses Value NDTF Cash and cash equivalents $ — $ — $ 95 $ — $ — $ 76 Equity securities 1,746 24 2,547 1,617 31 2,459 Corporate debt securities 15 3 291 27 — 296 Municipal bonds 13 1 277 16 — 279 U.S. government bonds 15 4 429 26 — 412 Other debt securities 1 — 6 1 — 6 Total NDTF Investments $ 1,790 $ 32 $ 3,645 $ 1,687 $ 31 $ 3,528 Other Investments Cash and cash equivalents $ — $ — $ 1 $ — $ — $ 1 Total Other Investments $ — $ — $ 1 $ — $ — $ 1 Total Investments $ 1,790 $ 32 $ 3,646 $ 1,687 $ 31 $ 3,529
Debt Securities, Available-for-sale	The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS. March 31, 2021 December 31, 2020 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses Value Gains Losses Value NDTF Cash and cash equivalents $ — $ — $ 95 $ — $ — $ 76 Equity securities 1,746 24 2,547 1,617 31 2,459 Corporate debt securities 15 3 291 27 — 296 Municipal bonds 13 1 277 16 — 279 U.S. government bonds 15 4 429 26 — 412 Other debt securities 1 — 6 1 — 6 Total NDTF Investments $ 1,790 $ 32 $ 3,645 $ 1,687 $ 31 $ 3,528 Other Investments Cash and cash equivalents $ — $ — $ 1 $ — $ — $ 1 Total Other Investments $ — $ — $ 1 $ — $ — $ 1 Total Investments $ 1,790 $ 32 $ 3,646 $ 1,687 $ 31 $ 3,529
Schedule of Realized Gain (Loss)	Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2021, and 2020, were as follows. Three Months Ended (in millions) March 31, 2021 March 31, 2020 FV-NI: Realized gains $ 12 $ 14 Realized losses 7 20 AFS: Realized gains 4 5 Realized losses 3 1
Duke Energy Florida
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading, and Equity Securities, FV-NI	The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS. March 31, 2021 December 31, 2020 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses Value Gains Losses Value NDTF Cash and cash equivalents $ — $ — $ 35 $ — $ — $ 71 Equity securities 86 — 94 79 — 91 Corporate debt securities — — 27 — — — U.S. government bonds — 5 461 — — 474 Total NDTF Investments (a) $ 86 $ 5 $ 617 $ 79 $ — $ 636 Other Investments Cash and cash equivalents $ — $ — $ 2 $ — $ — $ 1 Municipal bonds 2 — 26 3 — 26 Total Other Investments $ 2 $ — $ 28 $ 3 $ — $ 27 Total Investments $ 88 $ 5 $ 645 $ 82 $ — $ 663 (a) During the three months ended March 31, 2021, and the year ended December 31, 2020, Duke Energy Florida received reimbursements from the NDTF for costs related to ongoing decommissioning activity of Crystal River Unit 3.
Debt Securities, Available-for-sale	The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS. March 31, 2021 December 31, 2020 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses Value Gains Losses Value NDTF Cash and cash equivalents $ — $ — $ 35 $ — $ — $ 71 Equity securities 86 — 94 79 — 91 Corporate debt securities — — 27 — — — U.S. government bonds — 5 461 — — 474 Total NDTF Investments (a) $ 86 $ 5 $ 617 $ 79 $ — $ 636 Other Investments Cash and cash equivalents $ — $ — $ 2 $ — $ — $ 1 Municipal bonds 2 — 26 3 — 26 Total Other Investments $ 2 $ — $ 28 $ 3 $ — $ 27 Total Investments $ 88 $ 5 $ 645 $ 82 $ — $ 663 (a) During the three months ended March 31, 2021, and the year ended December 31, 2020, Duke Energy Florida received reimbursements from the NDTF for costs related to ongoing decommissioning activity of Crystal River Unit 3.
Duke Energy Indiana
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading, and Equity Securities, FV-NI	The following table presents the estimated fair value of investments in debt and equity securities; equity investments are measured at FV-NI and debt investments are classified as AFS. March 31, 2021 December 31, 2020 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses Value Gains Losses Value Investments Cash and cash equivalents $ — $ — $ — $ — $ — $ 1 Equity securities 62 — 102 58 — 97 Corporate debt securities — — 4 — — 3 Municipal bonds 1 1 35 1 — 38 U.S. government bonds — — 6 — — 4 Total Investments $ 63 $ 1 $ 147 $ 59 $ — $ 143
Debt Securities, Available-for-sale	The following table presents the estimated fair value of investments in debt and equity securities; equity investments are measured at FV-NI and debt investments are classified as AFS. March 31, 2021 December 31, 2020 Gross Gross Gross Gross Unrealized Unrealized Estimated Unrealized Unrealized Estimated Holding Holding Fair Holding Holding Fair (in millions) Gains Losses Value Gains Losses Value Investments Cash and cash equivalents $ — $ — $ — $ — $ — $ 1 Equity securities 62 — 102 58 — 97 Corporate debt securities — — 4 — — 3 Municipal bonds 1 1 35 1 — 38 U.S. government bonds — — 6 — — 4 Total Investments $ 63 $ 1 $ 147 $ 59 $ — $ 143

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
Fair Value Measurements (Tables)	Mar. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. Derivative amounts in the tables below for all Duke Energy Registrants exclude cash collateral, which is disclosed in Note 8. See Note 9 for additional information related to investments by major security type for the Duke Energy Registrants. March 31, 2021 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not Categorized NDTF cash and cash equivalents $ 193 $ 193 $ — $ — $ — NDTF equity securities 6,379 6,332 — — 47 NDTF debt securities 2,835 1,019 1,816 — — Other equity securities 154 154 — — — Other debt securities 277 49 228 — — Other cash and cash equivalents 222 222 — — — Derivative assets 206 1 203 2 — Total assets 10,266 7,970 2,247 2 47 Derivative liabilities (349) — (221) (128) — Net assets (liabilities) $ 9,917 $ 7,970 $ 2,026 $ (126) $ 47 December 31, 2020 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not Categorized NDTF cash and cash equivalents $ 177 $ 177 $ — $ — $ — NDTF equity securities 6,235 6,189 — — 46 NDTF debt securities 2,717 874 1,843 — — Other equity securities 146 146 — — — Other debt securities 285 37 248 — — Other cash and cash equivalents 127 127 — — — Derivative assets 61 1 53 7 — Total assets 9,748 7,551 2,144 7 46 Derivative liabilities (324) — (240) (84) — Net assets (liabilities) $ 9,424 $ 7,551 $ 1,904 $ (77) $ 46
Reconciliation Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs	The following tables provide reconciliations of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements. Derivatives (net) Three Months Ended March 31, (in millions) 2021 2020 Balance at beginning of period $ (77) $ (102) Total pretax realized or unrealized losses included in comprehensive income (44) — Purchases, sales, issuances and settlements: Settlements (7) (9) Total gains included on the Condensed Consolidated Balance Sheet 2 23 Balance at end of period $ (126) $ (88)
Quantitative Information Table - Level 3	The following tables include quantitative information about the Duke Energy Registrants' derivatives classified as Level 3. March 31, 2021 Weighted Fair Value Average Investment Type (in millions) Valuation Technique Unobservable Input Range Range Duke Energy Electricity contracts $ (128) RTO forward pricing Forward electricity curves – price per MWh $ 15.55 - $ 134.48 $ 34.80 Duke Energy Indiana FTRs 2 RTO auction pricing FTR price – per MWh (1.02) - 7.23 0.80 Duke Energy Total Level 3 derivatives $ (126) December 31, 2020 Weighted Fair Value Average Investment Type (in millions) Valuation Technique Unobservable Input Range Range Duke Energy Electricity contracts $ (84) Discounted cash flow Forward electricity curves – price per MWh $ 14.68 - $151.84 $28.84 Duke Energy Ohio FTRs 1 RTO auction pricing FTR price – per MWh 0.25 - 1.68 0.79 Duke Energy Indiana FTRs 6 RTO auction pricing FTR price – per MWh (2.40) - 7.41 1.05 Duke Energy Total Level 3 derivatives $ (77)
Schedule Of Long Term Debt Fair Value	The fair value and book value of long-term debt, including current maturities, is summarized in the following table. Estimates determined are not necessarily indicative of amounts that could have been settled in current markets. Fair value of long-term debt uses Level 2 measurements. March 31, 2021 December 31, 2020 (in millions) Book Value Fair Value Book Value Fair Value Duke Energy (a) $ 60,354 $ 64,641 $ 59,863 $ 69,292 Duke Energy Carolinas 12,329 13,461 12,218 14,917 Progress Energy 19,333 21,838 19,264 23,470 Duke Energy Progress 9,356 10,131 9,258 10,862 Duke Energy Florida 7,884 9,018 7,915 9,756 Duke Energy Ohio 3,090 3,397 3,089 3,650 Duke Energy Indiana 4,091 4,691 4,091 5,204 Piedmont 3,127 3,412 2,780 3,306 (a) Book value of long-term debt inc ludes $1.3 billion
Duke Energy Carolinas
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. March 31, 2021 (in millions) Total Fair Value Level 1 Level 2 Not Categorized NDTF cash and cash equivalents $ 63 $ 63 $ — $ — NDTF equity securities 3,738 3,691 — 47 NDTF debt securities 1,344 369 975 — Derivative assets 62 — 62 — Total assets 5,207 4,123 1,037 47 December 31, 2020 (in millions) Total Fair Value Level 1 Level 2 Not Categorized NDTF cash and cash equivalents $ 30 $ 30 $ — $ — NDTF equity securities 3,685 3,639 — 46 NDTF debt securities 1,250 192 1,058 — Derivative assets 20 — 20 — Total assets 4,985 3,861 1,078 46 Derivative liabilities (20) — (20) — Net assets $ 4,965 $ 3,861 $ 1,058 $ 46
Progress Energy
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. March 31, 2021 December 31, 2020 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 NDTF cash and cash equivalents $ 130 $ 130 $ — $ 147 $ 147 $ — NDTF equity securities 2,641 2,641 — 2,550 2,550 — NDTF debt securities 1,491 650 841 1,467 682 785 Other debt securities 26 — 26 26 — 26 Other cash and cash equivalents 107 107 — 106 106 — Derivative assets 103 — 103 33 — 33 Total assets 4,498 3,528 970 4,329 3,485 844 Derivative liabilities (28) — (28) (29) — (29) Net assets $ 4,470 $ 3,528 $ 942 $ 4,300 $ 3,485 $ 815
Duke Energy Progress
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. March 31, 2021 December 31, 2020 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 NDTF cash and cash equivalents $ 95 $ 95 $ — $ 76 $ 76 $ — NDTF equity securities 2,547 2,547 — 2,459 2,459 — NDTF debt securities 1,003 237 766 993 237 756 Other cash and cash equivalents 1 1 — 1 1 — Derivative assets 100 — 100 33 — 33 Total assets 3,746 2,880 866 3,562 2,773 789 Derivative liabilities (9) — (9) (14) — (14) Net assets $ 3,737 $ 2,880 $ 857 $ 3,548 $ 2,773 $ 775
Duke Energy Florida
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. March 31, 2021 December 31, 2020 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 NDTF cash and cash equivalents $ 35 $ 35 $ — $ 71 $ 71 $ — NDTF equity securities 94 94 — 91 91 — NDTF debt securities 488 413 75 474 445 29 Other debt securities 26 — 26 26 — 26 Other cash and cash equivalents 2 2 — 1 1 — Derivative assets 3 — 3 — — — Total assets 648 544 104 663 608 55 Derivative liabilities (3) — (3) — — — Net assets $ 645 $ 544 $ 101 $ 663 $ 608 $ 55
Duke Energy Indiana
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. March 31, 2021 December 31, 2020 (in millions) Total Fair Value Level 1 Level 2 Level 3 Total Fair Value Level 1 Level 2 Level 3 Other equity securities $ 102 $ 102 $ — $ — $ 97 $ 97 $ — $ — Other debt securities 45 — 45 — 45 — 45 — Other cash and cash equivalents — — — — 1 1 — — Derivative assets 2 — — 2 6 — — 6 Total assets $ 149 $ 102 $ 45 $ 2 $ 149 $ 98 $ 45 $ 6 Derivative liabilities — — — — (1) (1) — — Net assets $ 149 $ 102 $ 45 $ 2 $ 148 $ 97 $ 45 $ 6
Reconciliation Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs	The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements. Derivatives (net) Three Months Ended March 31, (in millions) 2021 2020 Balance at beginning of period $ 6 $ 11 Purchases, sales, issuances and settlements: Settlements (6) (6) Total gains (losses) included on the Condensed Consolidated Balance Sheet 2 (3) Balance at end of period $ 2 $ 2
Piedmont
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. March 31, 2021 December 31, 2020 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 Derivative assets $ 1 $ 1 $ — $ 1 $ 1 $ — Derivative liabilities (148) — (148) (122) — (122) Net (liabilities) assets $ (147) $ 1 $ (148) $ (121) $ 1 $ (122)
Reconciliation Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs	The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements. Derivatives (net) Three Months Ended March 31, (in millions) 2021 2020 Balance at beginning of period $ — $ (117) Total gains and settlements — 26 Balance at end of period $ — $ (91)

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	3 Months Ended
Variable Interest Entities (Tables)	Mar. 31, 2021
VIE primary beneficiary
Variable Interest Entities [Line Items]
Schedule Of Variable Interest Entities	The following table summarizes the amounts and expiration dates of the credit facilities and associated restricted receivables described above. Duke Energy Duke Energy Duke Energy Duke Energy Carolinas Progress Florida (in millions) CRC DERF DEPR DEFR Expiration date February 2023 December 2022 April 2023 April 2023 Credit facility amount $ 350 $ 475 $ 350 $ 250 Amounts borrowed at March 31, 2021 350 430 350 250 Amounts borrowed at December 31, 2020 350 364 250 250 Restricted Receivables at March 31, 2021 472 613 422 323 Restricted Receivables at December 31, 2020 547 696 500 397
VIE not primary beneficiary
Variable Interest Entities [Line Items]
Schedule Of Variable Interest Entities	The following tables summarize the impact of non-consolidated VIEs on the Condensed Consolidated Balance Sheets. March 31, 2021 Duke Energy Duke Duke Pipeline Commercial Energy Energy (in millions) Investments Renewables Total Ohio Indiana Receivables from affiliated companies $ — $ — $ — $ 46 $ 60 Other current assets 4 — 4 — $ — Investments in equity method unconsolidated affiliates 3 480 483 — — Deferred tax asset 29 — 29 — — Total assets $ 36 $ 480 $ 516 $ 46 $ 60 Other current liabilities 38 3 41 — — Other noncurrent liabilities 48 10 58 — — Total liabilities $ 86 $ 13 $ 99 $ — $ — Net (liabilities) assets $ (50) $ 467 $ 417 $ 46 $ 60 December 31, 2020 Duke Energy Duke Duke Pipeline Commercial Energy Energy (in millions) Investments Renewables Total Ohio Indiana Receivables from affiliated companies $ — $ — $ — $ 83 $ 110 Investments in equity method unconsolidated affiliates — 530 530 — — Other noncurrent assets 31 — 31 — — Total assets $ 31 $ 530 $ 561 $ 83 $ 110 Other current liabilities 928 5 933 — — Other noncurrent liabilities 8 10 18 — — Total liabilities $ 936 $ 15 $ 951 $ — $ — Net assets (liabilities) $ (905) $ 515 $ (390) $ 83 $ 110
DEFPF \| VIE primary beneficiary
Variable Interest Entities [Line Items]
Schedule Of Variable Interest Entities	The following table summarizes the impact of DEFPF on Duke Energy Florida's Condensed Consolidated Balance Sheets. (in millions) March 31, 2021 December 31, 2020 Receivables of VIEs $ 4 $ 4 Regulatory Assets: Current 54 53 Current Assets: Other 14 39 Other Noncurrent Assets: Regulatory assets 927 937 Current Liabilities: Other 2 10 Current maturities of long-term debt 55 55 Long-Term Debt 972 1,002
Commercial Renewables \| VIE primary beneficiary
Variable Interest Entities [Line Items]
Schedule Of Variable Interest Entities	The table below presents material balances reported on Duke Energy's Condensed Consolidated Balance Sheets related to Commercial Renewables VIEs. (in millions) March 31, 2021 December 31, 2020 Current Assets: Other $ 319 $ 257 Property, Plant and Equipment: Cost 6,860 6,394 Accumulated depreciation and amortization (1,297) (1,242) Other Noncurrent Assets: Other 66 67 Current maturities of long-term debt 167 167 Long-Term Debt 1,584 1,569 Other Noncurrent Liabilities: AROs 153 148 Other Noncurrent Liabilities: Other 331 316
CRC \| VIE not primary beneficiary
Variable Interest Entities [Line Items]
Schedule Of Variable Interest Entities	The following table shows the gross and net receivables sold. Duke Energy Ohio Duke Energy Indiana (in millions) March 31, 2021 December 31, 2020 March 31, 2021 December 31, 2020 Receivables sold $ 241 $ 270 $ 285 $ 344 Less: Retained interests 46 83 60 110 Net receivables sold $ 195 $ 187 $ 225 $ 234 The following table shows sales and cash flows related to receivables sold. Duke Energy Ohio Duke Energy Indiana Three Months Ended Three Months Ended March 31, March 31, (in millions) 2021 2020 2021 2020 Sales Receivables sold $ 561 $ 537 $ 698 $ 647 Loss recognized on sale 3 4 3 4 Cash flows Cash proceeds from receivables sold $ 596 $ 559 $ 746 $ 672 Return received on retained interests 1 2 2 2

Revenue (Tables)

Revenue (Tables)	3 Months Ended
Revenue (Tables)	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction	Supplemental requirements contracts that include contracted blocks of energy and capacity at contractually fixed prices have the following estimated remaining performance obligations: Remaining Performance Obligations (in millions) 2021 2022 2023 2024 2025 Thereafter Total Progress Energy $ 71 $ 107 $ 44 $ 45 $ 7 $ 51 $ 325 Duke Energy Progress 6 8 8 8 — — 30 Duke Energy Florida 65 99 36 37 7 51 295 Duke Energy Indiana 2 — 7 12 12 24 57 Remaining Performance Obligations (in millions) 2021 2022 2023 2024 2025 Thereafter Total Piedmont $ 50 $ 67 $ 64 $ 61 $ 60 $ 335 $ 637
Disaggregation of Revenue	Disaggregated revenues are presented as follows: Three Months Ended March 31, 2021 Duke Duke Duke Duke Duke (in millions) Duke Energy Progress Energy Energy Energy Energy By market or type of customer Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Electric Utilities and Infrastructure Residential $ 2,462 $ 793 $ 1,162 $ 560 $ 602 $ 195 $ 313 $ — General 1,419 502 624 306 318 104 189 — Industrial 662 256 207 145 62 31 167 — Wholesale 504 114 326 292 34 13 50 — Other revenues 226 74 160 83 77 22 18 — Total Electric Utilities and Infrastructure revenue from contracts with customers $ 5,273 $ 1,739 $ 2,479 $ 1,386 $ 1,093 $ 365 $ 737 $ — Gas Utilities and Infrastructure Residential $ 460 $ — $ — $ — $ — $ 110 $ — $ 351 Commercial 204 — — — — 48 — 156 Industrial 50 — — — — 7 — 43 Power Generation — — — — — — — 22 Other revenues 47 — — — — 5 — 26 Total Gas Utilities and Infrastructure revenue from contracts with customers $ 761 $ — $ — $ — $ — $ 170 $ — $ 598 Commercial Renewables Revenue from contracts with customers $ 54 $ — $ — $ — $ — $ — $ — $ — Other Revenue from contracts with customers $ 6 $ — $ — $ — $ — $ — $ — $ — Total revenue from contracts with customers $ 6,094 $ 1,739 $ 2,479 $ 1,386 $ 1,093 $ 535 $ 737 $ 598 Other revenue sources (a) $ 56 $ (23) $ 26 $ 15 $ 8 $ (3) $ 8 $ 8 Total revenues $ 6,150 $ 1,716 $ 2,505 $ 1,401 $ 1,101 $ 532 $ 745 $ 606 (a) Other revenue sources include revenues from leases, derivatives and alternative revenue programs that are not considered revenues from contracts with customers. Alternative revenue programs in certain jurisdictions include regulatory mechanisms that periodically adjust for over or under collection of related revenues. Three Months Ended March 31, 2020 Duke Duke Duke Duke Duke (in millions) Duke Energy Progress Energy Energy Energy Energy By market or type of customer Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Electric Utilities and Infrastructure Residential $ 2,261 $ 756 $ 1,064 $ 502 $ 562 $ 176 $ 265 $ — General 1,492 549 648 319 329 114 181 — Industrial 693 269 216 154 62 35 175 — Wholesale 497 114 321 279 42 7 55 — Other revenues 191 60 118 63 55 20 16 — Total Electric Utilities and Infrastructure revenue from contracts with customers $ 5,134 $ 1,748 $ 2,367 $ 1,317 $ 1,050 $ 352 $ 692 $ — Gas Utilities and Infrastructure Residential $ 362 $ — $ — $ — $ — $ 97 $ — $ 264 Commercial 169 — — — — 43 — 126 Industrial 41 — — — — 6 — 36 Power Generation — — — — — — — 11 Other revenues 30 — — — — 6 — 24 Total Gas Utilities and Infrastructure revenue from contracts with customers $ 602 $ — $ — $ — $ — $ 152 $ — $ 461 Commercial Renewables Revenue from contracts with customers $ 58 $ — $ — $ — $ — $ — $ — $ — Other Revenue from contracts with customers $ 6 $ — $ — $ — $ — $ — $ — $ — Total revenue from contracts with customers $ 5,800 $ 1,748 $ 2,367 $ 1,317 $ 1,050 $ 504 $ 692 $ 461 Other revenue sources (a) $ 149 $ — $ 55 $ 21 $ 30 $ (6) $ — $ 51 Total revenues $ 5,949 $ 1,748 $ 2,422 $ 1,338 $ 1,080 $ 498 $ 692 $ 512 (a) Other revenue sources include revenues from leases, derivatives and alternative revenue programs that are not considered revenues from contracts with customers. Alternative revenue programs in certain jurisdictions include regulatory mechanisms that periodically adjust for over or under collection of related revenues.
Reserve for Credit Losses for Trade and Other Receivables	The following table presents the reserve for credit losses for trade and other receivables based on adoption of the new standard. Three Months Ended March 31, 2020 and 2021 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Balance at December 31, 2019 $ 76 $ 10 $ 16 $ 8 $ 7 $ 4 $ 3 $ 6 Cumulative Change in Accounting Principle 5 1 2 1 1 — — 1 Write-Offs (10) (3) (4) (2) (2) — — (1) Credit Loss Expense 18 3 6 2 5 1 — 3 Balance at March 31, 2020 $ 89 $ 11 $ 20 $ 9 $ 11 $ 5 $ 3 $ 9 Balance at December 31, 2020 $ 146 $ 23 $ 37 $ 23 $ 14 $ 4 $ 3 $ 12 Write-Offs (21) (8) (10) (5) (5) — — (1) Credit Loss Expense 17 10 7 2 5 — — 3 Other Adjustments 5 9 3 3 1 — — — Balance at March 31, 2021 $ 147 $ 34 $ 37 $ 23 $ 15 $ 4 $ 3 $ 14
Aging of Trade Receivables	The aging of trade receivables is presented in the table below. Duke Energy considers receivables greater than 30 days outstanding past due. March 31, 2021 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Unbilled Revenue (a)(b) $ 758 $ 293 $ 183 $ 90 $ 93 $ 4 $ 16 $ 44 0-30 days 1,656 337 633 357 275 55 35 185 30-60 days 181 62 46 31 15 8 3 21 60-90 days 46 15 11 6 5 3 1 6 90+ days 120 31 26 4 22 28 11 7 Deferred Payment Arrangements (c) 170 80 53 37 16 4 — 8 Trade and Other Receivables $ 2,931 $ 818 $ 952 $ 525 $ 426 $ 102 $ 66 $ 271 December 31, 2020 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Unbilled Revenue (a)(b) $ 969 $ 328 $ 283 $ 167 $ 116 $ 2 $ 16 $ 86 0-30 days 1,789 445 707 398 307 60 26 149 30-60 days 185 80 54 25 29 8 3 8 60-90 days 22 1 10 4 6 2 1 3 90+ days 119 16 32 9 23 30 12 9 Deferred Payment Arrangements (c) 215 96 80 52 28 — — 7 Trade and Other Receivables $ 3,299 $ 966 $ 1,166 $ 655 $ 509 $ 102 $ 58 $ 262 (a) Unbilled revenues are recognized by applying customer billing rates to the estimated volumes of energy or natural gas delivered but not yet billed and are included within Receivables and Receivables of VIEs on the Condensed Consolidated Balance Sheets. (b) Duke Energy Ohio and Duke Energy Indiana sell, on a revolving basis, nearly all of their retail accounts receivable, including receivables for unbilled revenues, to an affiliate, CRC, and account for the transfers of receivables as sales. Accordingly, the receivables sold are not reflected on the Condensed Consolidated Balance Sheets of Duke Energy Ohio and Duke Energy Indiana. See Note 11 for further information. These receivables for unbilled revenues are $55 million and $87 million for Duke Energy Ohio and Duke Energy Indiana, respectively, as of March 31, 2021, and $87 million and $134 million for Duke Energy Ohio and Duke Energy Indiana, respectively, as of December 31, 2020. (c) Due to certain customer financial hardships created by the COVID-19 pandemic and resulting stay-at-home orders, Duke Energy permitted customers to defer payment of past-due amounts through an installment payment plan over a period of several months.

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
Stockholders' Equity (Tables)	Mar. 31, 2021
Equity [Abstract]
Schedule Of Earnings Per Share	The following table presents Duke Energy’s basic and diluted EPS calculations, the weighted average number of common shares outstanding and common and preferred share dividends declared. Three Months Ended March 31, (in millions, except per share amounts) 2021 2020 Net income available to Duke Energy common stockholders $ 953 $ 899 Accumulated preferred stock dividends adjustment 12 13 Less: Impact of participating securities 1 1 Income from continuing operations available to Duke Energy common stockholders $ 964 $ 911 Weighted average common shares outstanding – basic 769 734 Equity forwards — 2 Weighted average common shares outstanding – diluted 769 736 EPS available to Duke Energy common stockholders Basic and diluted $ 1.25 $ 1.24 Potentially dilutive items excluded from the calculation (a) 2 2 Dividends declared per common share $ 0.965 $ 0.945 Dividends declared on Series A preferred stock per depositary share (b) $ 0.359 $ 0.359 Dividends declared on Series B preferred stock per share (c) $ 24.375 $ 24.917 (a) Performance stock awards were not included in the dilutive securities calculation because the performance measures related to the awards had not been met. (b) 5.75% Series A Cumulative Redeemable Perpetual Preferred Stock dividends are payable quarterly in arrears on the 16th day of March, June, September and December. The preferred stock has a $25 liquidation preference per depositary share. (c) 4.875% Series B Fixed-Rate Reset Cumulative Redeemable Perpetual Preferred Stock dividends are payable semiannually in arrears on the 16th day of March and September. The preferred stock has a $1,000 liquidation preference per share.

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	3 Months Ended
Employee Benefit Plans (Tables)	Mar. 31, 2021
Qualified Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Components of Net Periodic Pension Costs	The following tables include the components of net periodic pension costs for qualified pension plans. Three Months Ended March 31, 2021 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Service cost $ 44 $ 14 $ 13 $ 7 $ 5 $ 1 $ 2 $ 1 Interest cost on projected benefit obligation 55 13 17 7 10 3 5 2 Expected return on plan assets (139) (35) (47) (21) (26) (7) (10) (5) Amortization of actuarial loss 33 7 10 5 5 2 3 2 Amortization of prior service credit (7) (2) (1) — — — — (1) Amortization of settlement charges 2 1 1 — — — — — Net periodic pension costs $ (12) $ (2) $ (7) $ (2) $ (6) $ (1) $ — $ (1) Three Months Ended March 31, 2020 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Service cost $ 41 $ 12 $ 12 $ 6 $ 5 $ 1 $ 2 $ 1 Interest cost on projected benefit obligation 67 16 21 10 12 4 6 2 Expected return on plan assets (143) (36) (48) (22) (25) (7) (11) (5) Amortization of actuarial loss 34 7 11 5 6 2 3 2 Amortization of prior service credit (8) (2) (1) — — — — (2) Amortization of settlement charges 2 1 1 — — — — — Net periodic pension costs $ (7) $ (2) $ (4) $ (1) $ (2) $ — $ — $ (2)

Income Taxes (Tables)

Income Taxes (Tables)	3 Months Ended
Income Taxes (Tables)	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Summary of Effective Tax Rates	The ETRs from continuing operations for each of the Duke Energy Registrants are included in the following table. Three Months Ended March 31, 2021 2020 Duke Energy 8.2 % 13.3 % Duke Energy Carolinas 6.9 % 16.1 % Progress Energy 12.9 % 17.5 % Duke Energy Progress 8.3 % 17.1 % Duke Energy Florida 19.3 % 20.0 % Duke Energy Ohio 13.3 % 17.7 % Duke Energy Indiana 17.6 % 20.8 % Piedmont 11.4 % 10.1 %

Organization and Basis of Pre_4

Organization and Basis of Presentation (Narrative) (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Noncontrolling Interest [Line Items]
Other current liabilities	$ 1,858,000,000	$ 2,936,000,000
ACP
Noncontrolling Interest [Line Items]
Other current liabilities	$ 46,000,000	$ 936,000,000

Organization and Basis of Pre_5

Organization and Basis of Presentation (Schedule of Cash Received and Allocated Losses from Subsidiaries, Noncontrolling Interest) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash received for the sale of noncontrolling interest to tax equity members	$ 303	$ 103
Cash received for the sale of noncontrolling interest to pro rata share members	0	0
Total Noncontrolling Interest Capital Contributions	303	103
Allocated losses to noncontrolling tax equity members utilizing the HLBV method	43	49
Allocated losses (gains) to noncontrolling members based on pro rata shares of ownership	8	(1)
Total Noncontrolling Interest Allocated Losses	$ 51	$ 48

Organization and Basis of Pre_6

Organization and Basis of Presentation (Schedule of Cash and Cash Equivalents) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 379	$ 259
Other	210	194
Other Noncurrent Assets
Other	103	103
Total cash, cash equivalents and restricted cash	692	556	$ 1,698	$ 573
Progress Energy
Current Assets
Cash and cash equivalents	74	59
Other	13	39
Other Noncurrent Assets
Other	102	102
Total cash, cash equivalents and restricted cash	189	200	125	126
Duke Energy Florida
Current Assets
Cash and cash equivalents	22	11
Other	13	39
Other Noncurrent Assets
Total cash, cash equivalents and restricted cash	$ 35	$ 50	$ 25	$ 56

Organization and Basis of Pre_7

Organization and Basis of Presentation (Schedule of Inventory) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Public Utilities, Inventory [Line Items]
Inventory	$ 3,076	$ 3,167
Materials and supplies
Public Utilities, Inventory [Line Items]
Inventory	2,365	2,312
Coal
Public Utilities, Inventory [Line Items]
Inventory	464	561
Natural gas, oil and other fuel
Public Utilities, Inventory [Line Items]
Inventory	247	294
Duke Energy Carolinas
Public Utilities, Inventory [Line Items]
Inventory	1,021	1,010
Duke Energy Carolinas \| Materials and supplies
Public Utilities, Inventory [Line Items]
Inventory	816	785
Duke Energy Carolinas \| Coal
Public Utilities, Inventory [Line Items]
Inventory	170	186
Duke Energy Carolinas \| Natural gas, oil and other fuel
Public Utilities, Inventory [Line Items]
Inventory	35	39
Progress Energy
Public Utilities, Inventory [Line Items]
Inventory	1,336	1,375
Progress Energy \| Materials and supplies
Public Utilities, Inventory [Line Items]
Inventory	1,011	999
Progress Energy \| Coal
Public Utilities, Inventory [Line Items]
Inventory	160	193
Progress Energy \| Natural gas, oil and other fuel
Public Utilities, Inventory [Line Items]
Inventory	165	183
Duke Energy Progress
Public Utilities, Inventory [Line Items]
Inventory	882	911
Duke Energy Progress \| Materials and supplies
Public Utilities, Inventory [Line Items]
Inventory	680	673
Duke Energy Progress \| Coal
Public Utilities, Inventory [Line Items]
Inventory	101	131
Duke Energy Progress \| Natural gas, oil and other fuel
Public Utilities, Inventory [Line Items]
Inventory	101	107
Duke Energy Florida
Public Utilities, Inventory [Line Items]
Inventory	455	464
Duke Energy Florida \| Materials and supplies
Public Utilities, Inventory [Line Items]
Inventory	332	325
Duke Energy Florida \| Coal
Public Utilities, Inventory [Line Items]
Inventory	59	63
Duke Energy Florida \| Natural gas, oil and other fuel
Public Utilities, Inventory [Line Items]
Inventory	64	76
Duke Energy Ohio
Public Utilities, Inventory [Line Items]
Inventory	108	110
Duke Energy Ohio \| Materials and supplies
Public Utilities, Inventory [Line Items]
Inventory	77	78
Duke Energy Ohio \| Coal
Public Utilities, Inventory [Line Items]
Inventory	12	16
Duke Energy Ohio \| Natural gas, oil and other fuel
Public Utilities, Inventory [Line Items]
Inventory	19	16
Duke Energy Indiana
Public Utilities, Inventory [Line Items]
Inventory	436	473
Duke Energy Indiana \| Materials and supplies
Public Utilities, Inventory [Line Items]
Inventory	313	307
Duke Energy Indiana \| Coal
Public Utilities, Inventory [Line Items]
Inventory	122	165
Duke Energy Indiana \| Natural gas, oil and other fuel
Public Utilities, Inventory [Line Items]
Inventory	1	1
Piedmont
Public Utilities, Inventory [Line Items]
Inventory	37	68
Piedmont \| Materials and supplies
Public Utilities, Inventory [Line Items]
Inventory	11	12
Piedmont \| Natural gas, oil and other fuel
Public Utilities, Inventory [Line Items]
Inventory	$ 26	$ 56

Organization and Basis of Pre_8

Organization and Basis of Presentation (Schedule of New Accounting Pronouncements) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings		$ 49,658	$ 49,184	$ 48,083	$ 47,951
Accounting Standards Update [Extensible List]	ASU 2016-13
Progress Energy
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings		16,530	16,241	15,877	15,593
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings		2,680	2,471	4,221	4,108
Retained Earnings \| Progress Energy
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings		$ 7,400	$ 7,109	$ 6,747	6,465
Cumulative Change in Accounting Principle \| Retained Earnings \| Revision of Prior Period, Accounting Standards Update, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings					120
Cumulative Change in Accounting Principle \| Retained Earnings \| Revision of Prior Period, Accounting Standards Update, Adjustment \| Duke Energy Carolinas
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings					16
Cumulative Change in Accounting Principle \| Retained Earnings \| Revision of Prior Period, Accounting Standards Update, Adjustment \| Progress Energy
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings					2
Cumulative Change in Accounting Principle \| Retained Earnings \| Revision of Prior Period, Accounting Standards Update, Adjustment \| Duke Energy Progress
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings					1
Cumulative Change in Accounting Principle \| Retained Earnings \| Revision of Prior Period, Accounting Standards Update, Adjustment \| Duke Energy Florida
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings					1
Cumulative Change in Accounting Principle \| Retained Earnings \| Revision of Prior Period, Accounting Standards Update, Adjustment \| Piedmont
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total pretax impact to Retained Earnings					$ 1

Business Segments (Narrative) (

Business Segments (Narrative) (Details) $ in Millions	3 Months Ended
Business Segments (Narrative) (Details) $ in Millions	Mar. 31, 2021USD ($)segment
Duke Energy Ohio
Segment Reporting Information [Line Items]
Number of reportable segments \| segment	2
Wind and solar \| Nonregulated
Segment Reporting Information [Line Items]
Renewable merchant plants \| $	$ 210
Joint owner ownership percentage	51.00%

Business Segments (Business Seg

Business Segments (Business Segment Data) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Segment Reporting Information [Line Items]
Operating revenues	$ 6,150	$ 5,949
Segment income (loss)	953	899
Less: Noncontrolling interests	(51)	(48)
Add: Preferred stock dividend	39	39
Net Income	941	890
Segment assets	163,465		$ 162,388
Unregulated operating revenue	(182)	(187)
Incurred costs	1,402	1,339
Equity in (losses) earnings of unconsolidated affiliates	17	(44)
Electric Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	5,273	5,174
Gas Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	752	640
Gas Utilities and Infrastructure \| Asset Impairment for Regulatory Action
Segment Reporting Information [Line Items]
Equity in (losses) earnings of unconsolidated affiliates	6
Commercial Renewables
Segment Reporting Information [Line Items]
Operating revenues	119	129
Total Reportable Segments
Segment Reporting Information [Line Items]
Operating revenues	6,144	5,943
Other
Segment Reporting Information [Line Items]
Operating revenues	6	6
Other
Segment Reporting Information [Line Items]
Severance charge reversal		98
Operating Segments \| Electric Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	5,281	5,183
Segment income (loss)	820	705
Segment assets	138,734
Operating Segments \| Gas Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	775	664
Segment income (loss)	245	249
Segment assets	14,139
Operating Segments \| Commercial Renewables
Segment Reporting Information [Line Items]
Operating revenues	119	129
Segment income (loss)	27	57
Segment assets	6,894
Operating Segments \| Commercial Renewables \| Texas Storm Uri
Segment Reporting Information [Line Items]
Segment income (loss)	(35)
Less: Noncontrolling interests	12
Unregulated operating revenue	8
Incurred costs	2
Equity in (losses) earnings of unconsolidated affiliates	29
Operating Segments \| Total Reportable Segments
Segment Reporting Information [Line Items]
Operating revenues	6,175	5,976
Segment income (loss)	1,092	1,011
Segment assets	159,767
Other \| Other
Segment Reporting Information [Line Items]
Operating revenues	26	23
Segment income (loss)	(139)	(112)
Segment assets	3,710
Eliminations
Segment Reporting Information [Line Items]
Operating revenues	(51)	(50)
Segment assets	(12)
Eliminations \| Electric Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	8	9
Eliminations \| Gas Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	23	24
Eliminations \| Total Reportable Segments
Segment Reporting Information [Line Items]
Operating revenues	31	33
Eliminations \| Other
Segment Reporting Information [Line Items]
Operating revenues	20	17
Duke Energy Ohio
Segment Reporting Information [Line Items]
Operating revenues	532	498
Segment income (loss)	91	65
Segment assets	10,141		$ 10,025
Incurred costs	108	123
Duke Energy Ohio \| Operating Segments \| Electric Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	363	346
Segment income (loss)	50	30
Segment assets	6,544
Duke Energy Ohio \| Operating Segments \| Gas Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	169	152
Segment income (loss)	43	36
Segment assets	3,575
Duke Energy Ohio \| Operating Segments \| Total Reportable Segments
Segment Reporting Information [Line Items]
Operating revenues	532	498
Segment income (loss)	93	66
Segment assets	10,119
Duke Energy Ohio \| Other \| Other
Segment Reporting Information [Line Items]
Segment income (loss)	(2)	$ (1)
Segment assets	29
Duke Energy Ohio \| Eliminations
Segment Reporting Information [Line Items]
Segment assets	$ (7)

Regulatory Matters (Duke Energy

Regulatory Matters (Duke Energy Carolinas and Duke Energy Progress) (Details) - USD ($) $ in Millions	Jan. 27, 2021	Jan. 22, 2021	Dec. 31, 2020	Mar. 31, 2020
Public Utilities, General Disclosures [Line Items]
Impairment of assets and other charges				$ 2
Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Impairment of assets and other charges				$ 2
Duke Energy Carolinas \| 15-year storm recovery bond
Public Utilities, General Disclosures [Line Items]
Facility term	20 years
CCR Settlement Agreement \| Duke Energy Carolinas and Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Recovery costs not sought		$ 1,000
Recovery costs amortization period		5 years
Equity return on deferred coal ash cost future cases		1.50%
CCR Settlement Agreement \| Duke Energy Carolinas and Duke Energy Progress \| NCUC
Public Utilities, General Disclosures [Line Items]
Public utilities, requested equity capital structure, percentage		48.00%
Public utilities, requested debt capital structure, percentage		52.00%
CCR Settlement Agreement \| Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Impairment of assets and other charges			$ 454
Reversal of regulated electric operating revenues			50
CCR Settlement Agreement \| Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Impairment of assets and other charges			494
Reversal of regulated electric operating revenues			$ 102
2020 North Carolina Storm Securitization Filings \| Duke Energy Carolinas \| NCUC \| Storm costs
Public Utilities, General Disclosures [Line Items]
Regulatory assets	$ 287
2020 North Carolina Storm Securitization Filings \| Duke Energy Progress \| NCUC \| Storm costs
Public Utilities, General Disclosures [Line Items]
Regulatory assets	$ 920

Regulatory Matters (Regulatory

Regulatory Matters (Regulatory Matters Narrative - Duke Energy Carolinas) (Details) - Duke Energy Carolinas - USD ($) $ in Millions	Apr. 12, 2021	Mar. 31, 2021	Sep. 30, 2019	May 21, 2019	Nov. 08, 2018	Feb. 28, 2018	Aug. 25, 2017
PSCSC \| South Carolina Rate Case 2018
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount					$ 168
Approved return on equity percentage				9.50%
Public utilities, approved equity capital structure, percentage				53.00%
Public utilities, approved debt capital structure, percentage				47.00%
Change in tax rate, deferred tax liability, income tax benefit				$ 66
Measurement period adjustment, income tax expense (benefit)				$ 45
PSCSC \| South Carolina Rate Case 2018 \| North Carolina Department of Revenue \| State and local jurisdiction
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period				5 years
State and local taxes reduction amount				$ 17
NCUC \| 2017 North Carolina Rate Case
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount							$ 647
Requested return on equity, percent						9.90%
Public utilities, requested equity capital structure, percentage						52.00%
Public utilities, requested debt capital structure, percentage						48.00%
NCUC \| 2019 North Carolina Rate Case
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount			$ 291
Requested rate increase, percentage			6.00%
Requested rate increase (decrease), gross amount			$ 445
Requested rate increase (decrease), rider reduction			$ 154
NCUC \| 2019 North Carolina Rate Case, additional Agreement and Stipulation of Partial Settlement
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage		9.60%
Public utilities, approved equity capital structure, percentage		52.00%
Public utilities, approved debt capital structure, percentage		48.00%
NCUC \| 2019 North Carolina Rate Case, additional Agreement and Stipulation of Partial Settlement \| Subsequent event
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amended amount	$ 33
Grid Improvement \| NCUC \| 2019 North Carolina Rate Case, additional Agreement and Stipulation of Partial Settlement
Public Utilities, General Disclosures [Line Items]
Regulatory assets		$ 800
Storm costs \| NCUC \| 2019 North Carolina Rate Case, additional Agreement and Stipulation of Partial Settlement
Public Utilities, General Disclosures [Line Items]
Regulatory assets		$ 213
Deferred project costs \| PSCSC \| South Carolina Rate Case 2018
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period				12 years
Regulatory assets				$ 125
Asset retirement obligations - coal ash \| PSCSC \| South Carolina Rate Case 2018
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period				5 years
Regulatory assets				$ 96
Recovery costs denied				$ 115
Asset retirement obligations - unprotected EDIT, Property, Plant and Equipment \| PSCSC \| South Carolina Rate Case 2018
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period				20 years
Asset retirement obligations - unprotected EDIT \| PSCSC \| South Carolina Rate Case 2018
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period				5 years
Asset retirement obligations - deferred revenue \| PSCSC \| South Carolina Rate Case 2018
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period				5 years

Regulatory Matters (Regulator_2

Regulatory Matters (Regulatory Matters Narrative - Duke Energy Progress) (Details) - Duke Energy Progress $ in Millions

Apr. 26, 2021USD ($)

Apr. 16, 2021USD ($)

Oct. 16, 2020

Oct. 30, 2019USD ($)

Oct. 11, 2019

May 21, 2019USD ($)

Nov. 08, 2018USD ($)

Nov. 22, 2017

Jun. 01, 2017USD ($)

Dec. 31, 2020USD ($)

Jul. 27, 2020MW

Mar. 31, 2020USD ($)

Sep. 30, 2019USD ($)

Hurricane Dorian storm damage

Public Utilities, General Disclosures [Line Items]

Estimated storm costs - O&M

$ 168

Estimated storm costs - capital investments

$ 4

Western Carolinas Modernization Plan

Public Utilities, General Disclosures [Line Items]

Generation capacity (MW) | MW

FERC | FERC Return on Equity Complaint, NCEMPA

Public Utilities, General Disclosures [Line Items]

Approved return on equity percentage

11.00%

FERC | FERC Return on Equity Complaint, NCEMC

Public Utilities, General Disclosures [Line Items]

Approved return on equity percentage

11.00%

PSCSC | South Carolina Rate Case 2018

Public Utilities, General Disclosures [Line Items]

Requested rate increase (decrease), amount

$ 59

Approved return on equity percentage

9.50%

Public utilities, approved equity capital structure, percentage

53.00%

Public utilities, approved debt capital structure, percentage

47.00%

Change in tax rate, deferred tax liability, income tax benefit

$ 17

Measurement period adjustment, income tax expense (benefit)

NCUC | 2017 North Carolina Rate Case

Public Utilities, General Disclosures [Line Items]

Requested rate increase (decrease), amount

$ 477

Requested rate increase (decrease), amended amount

$ 420

Requested return on equity, percent

9.90%

Public utilities, requested equity capital structure, percentage

52.00%

Public utilities, requested debt capital structure, percentage

48.00%

NCUC | 2019 North Carolina Rate Case

Public Utilities, General Disclosures [Line Items]

Requested rate increase (decrease), amount

$ 464

Requested rate increase, percentage

12.30%

Requested rate increase (decrease), gross amount

$ 586

Rider reduction

122

Requested rate increase (decrease), rider reduction

$ 120

NCUC | 2019 North Carolina Rate Case | Subsequent event

Public Utilities, General Disclosures [Line Items]

Requested rate increase (decrease), amount

$ 178

NCUC | 2019 North Carolina Rate Case, additional Agreement and Stipulation of Partial Settlement | Subsequent event

Public Utilities, General Disclosures [Line Items]

Approved return on equity percentage

9.60%

Public utilities, approved equity capital structure, percentage

52.00%

Public utilities, approved debt capital structure, percentage

48.00%

State and local jurisdiction | North Carolina Department of Revenue | PSCSC | South Carolina Rate Case 2018

Public Utilities, General Disclosures [Line Items]

State and local taxes increase amount

Grid Improvement | NCUC | 2019 North Carolina Rate Case, additional Agreement and Stipulation of Partial Settlement | Subsequent event

Public Utilities, General Disclosures [Line Items]

Regulatory assets

$ 400

Storm costs | Hurricane Dorian storm damage

Public Utilities, General Disclosures [Line Items]

Regulatory assets

$ 145

Storm costs | NCUC | 2019 North Carolina Rate Case, additional Agreement and Stipulation of Partial Settlement | Subsequent event

Public Utilities, General Disclosures [Line Items]

Regulatory assets

$ 714

Asset retirement obligations - coal ash | PSCSC | South Carolina Rate Case 2018

Public Utilities, General Disclosures [Line Items]

Regulatory assets

Recovery costs denied

$ 65

Regulatory asset, amortization period

5 years

Asset retirement obligations - unprotected EDIT, Property, Plant and Equipment | PSCSC | South Carolina Rate Case 2018

Public Utilities, General Disclosures [Line Items]

Regulatory asset, amortization period

20 years

Asset retirement obligations - unprotected EDIT | PSCSC | South Carolina Rate Case 2018

Public Utilities, General Disclosures [Line Items]

Regulatory asset, amortization period

5 years

Asset retirement obligations - deferred revenue | PSCSC | South Carolina Rate Case 2018

Public Utilities, General Disclosures [Line Items]

Regulatory asset, amortization period

3 years

Regulatory Matters (Regulator_3

Regulatory Matters (Regulatory Matters Narrative - Duke Energy Florida) (Details) - Duke Energy Florida

Jan. 14, 2021USD ($)

Jul. 01, 2020USD ($)plantMW

Dec. 31, 2024USD ($)

Dec. 31, 2023USD ($)

Dec. 31, 2022USD ($)

Dec. 31, 2020USD ($)

Sep. 30, 2020USD ($)

May 19, 2020USD ($)

Mar. 31, 2020USD ($)

Dec. 19, 2019USD ($)

Nov. 22, 2019USD ($)

Apr. 30, 2019USD ($)

FPSC

Public Utilities, General Disclosures [Line Items]

Number of solar plants | plant

Generation capacity (MW) | MW

750

2021 Settlement | FPSC

Public Utilities, General Disclosures [Line Items]

Public utilities, approved equity capital structure, percentage

53.00%

Public utilities, approved debt capital structure, percentage

47.00%

Public utilities, basis points, increase, percentage

0.25%

Contract with customer, asset, after allowance for credit loss, noncurrent

$ 173,000,000

Future investment in infrastructure

$ 1,000,000,000

2021 Settlement | FPSC | US Treasury Securities

Public Utilities, General Disclosures [Line Items]

Public utilities, basis points, increase, percentage

5000.00%

2021 Settlement | FPSC | Minimum

Public Utilities, General Disclosures [Line Items]

Approved return on equity percentage

8.85%

2021 Settlement | FPSC | Minimum | US Treasury Securities

Public Utilities, General Disclosures [Line Items]

Approved return on equity percentage

9.85%

2021 Settlement | FPSC | Maximum

Public Utilities, General Disclosures [Line Items]

Approved return on equity percentage

10.85%

2021 Settlement | FPSC | Maximum | US Treasury Securities

Public Utilities, General Disclosures [Line Items]

Approved return on equity percentage

10.10%

2021 Settlement | FPSC | Weighted Average

Public Utilities, General Disclosures [Line Items]

Approved return on equity percentage

9.85%

2021 Settlement | FPSC | Subsequent event

Public Utilities, General Disclosures [Line Items]

Approved rate increase, amount

$ 79,000,000

$ 49,000,000

$ 67,000,000

Hurricane Michael storm damage

Public Utilities, General Disclosures [Line Items]

Estimated storm costs - capital and operation maintenance

$ 80,000,000

$ 42,000,000

Hurricane Michael storm damage | FPSC

Public Utilities, General Disclosures [Line Items]

Estimated storm costs - capital and operation maintenance

$ 223,000,000

Amount of recovery costs sought

$ 188,000,000

$ 191,000,000

Requested supplemental true-up

$ 3,000,000

Hurricane Dorian storm damage | FPSC

Public Utilities, General Disclosures [Line Items]

Estimated storm costs - capital and operation maintenance

$ 169,000,000

Actual storm costs - capital and operation maintenance

$ 145,000,000

Solar Project

Public Utilities, General Disclosures [Line Items]

Estimated cost of facilities

$ 1,000,000,000

Estimated cost of facilities period

4 years

Regulatory Matters (Regulator_4

Regulatory Matters (Regulatory Matters Narrative - Duke Energy Ohio) (Details) - Duke Energy Ohio $ in Millions	3 Months Ended
	Mar. 31, 2021USD ($)site	Jul. 23, 2020USD ($)	Mar. 31, 2020USD ($)	Jan. 01, 2020plant	Jul. 12, 2019USD ($)	Mar. 29, 2019USD ($)	Sep. 28, 2018USD ($)
Public Utilities, General Disclosures [Line Items]
Number of nuclear generating facilities eligible for funding \| plant				2
Natural Gas Pipeline extension \| OPSB \| Minimum
Public Utilities, General Disclosures [Line Items]
Estimated capital cost excluding AFUDC	$ 163
Natural Gas Pipeline extension \| OPSB \| Maximum
Public Utilities, General Disclosures [Line Items]
Estimated capital cost excluding AFUDC	$ 245
MGP Cost Recovery - 2009 Through 2012 \| PUCO
Public Utilities, General Disclosures [Line Items]
Number of environmental remediation sites \| site	2
Regulatory assets	$ 55
MGP Cost Recovery - 2013 Through 2017 \| PUCO
Public Utilities, General Disclosures [Line Items]
Regulatory assets							$ 26
MGP Cost Recovery - 2013 Through 2017 \| PUCO \| MGP Costs - regulatory disallowance
Public Utilities, General Disclosures [Line Items]
Regulatory assets							$ 12
MGP Cost Recovery - 2018 \| PUCO
Public Utilities, General Disclosures [Line Items]
Regulatory assets						$ 20
MGP Cost Recovery - 2018 \| PUCO \| MGP Costs - regulatory disallowance
Public Utilities, General Disclosures [Line Items]
Regulatory assets					$ 11
MGP Cost Recovery - 2019 \| PUCO
Public Utilities, General Disclosures [Line Items]
Regulatory assets			$ 39
MGP Cost Recovery - 2019 \| PUCO \| MGP Costs - regulatory disallowance
Public Utilities, General Disclosures [Line Items]
Regulatory assets		$ 4

Regulatory Matters (Regulator_5

Regulatory Matters (Regulatory Matters Narrative - Duke Energy Indiana) (Details) - Duke Energy Indiana - IURC - Indiana rate case 2019 - USD ($) $ in Millions	Jun. 29, 2020	Dec. 04, 2019	Jul. 02, 2019
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount			$ 395
Requested rate increase, percentage, net of tax		15.60%
Requested rate increase (decrease), amended amount		$ 396
Approved rate increase, amount	$ 146
Public utilities, approved rate increase (decrease), percentage	5.70%
Approved return on equity percentage	9.70%
Public utilities, approved equity capital structure, percentage	53.00%
Rate base	$ 10,200
Reduction of requested rate base	$ 200
Reduction due to depreciation methodology	50.00%
Reduction due to approved return on equity	20.00%
Requested return on equity, percent	10.40%
Reduction due to earnings adjustments	20.00%
Estimated step one rate	75.00%
Estimated step two rate	25.00%

Regulatory Matters (Regulator_6

Regulatory Matters (Regulatory Matters Narrative - Piedmont) (Details) - Piedmont - USD ($) $ in Millions	Mar. 22, 2021	Feb. 16, 2021	Jul. 02, 2020	Dec. 31, 2020
2020 Tennessee Rate Case \| TPUC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount		$ 16	$ 30	$ 26
Increase in annual revenue, percent			15.00%
Requested return on equity, percent		9.80%
2019 North Carolina Rate Case, additional Agreement and Stipulation of Partial Settlement \| NCUC
Public Utilities, General Disclosures [Line Items]
Increase in annual revenue, percent	10.00%
Requested rate increase (decrease), amended amount	$ 109
Plants rolled into base rate	30.00%

Regulatory Matters (Other Regul

Regulatory Matters (Other Regulatory Matters) (Details) - USD ($)	1 Months Ended	3 Months Ended
	Jun. 30, 2020	Mar. 31, 2021	Mar. 31, 2020	Feb. 28, 2021	Dec. 31, 2020
Public Utilities, General Disclosures [Line Items]
Equity in losses (earnings) of unconsolidated affiliates		$ 17,000,000	$ (44,000,000)
Current Liabilities: Other		1,858,000,000			$ 2,936,000,000
Asset retirement obligations		709,000,000			718,000,000
ACP
Public Utilities, General Disclosures [Line Items]
Current Liabilities: Other		46,000,000			$ 936,000,000
ACP \| ACP
Public Utilities, General Disclosures [Line Items]
Equity in losses (earnings) of unconsolidated affiliates	$ 2,100,000,000
Current Liabilities: Other		38,000,000
Other Noncurrent Liabilities		48,000,000
ACP \| ACP \| Current liabilities
Public Utilities, General Disclosures [Line Items]
Guarantor obligations settled				$ 855,000,000
Asset retirement obligations		$ 86,000,000
ACP
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage		47.00%

Regulatory Matters (Schedule of

Regulatory Matters (Schedule of Net Carrying Value Of Facilities and Megawatt Capacity) (Details) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021USD ($)MW	Dec. 31, 2034asset	Dec. 31, 2020USD ($)
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	$ 107,629		$ 106,782
Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	33,337		33,187
Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	23,042		22,987
Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	16,813		16,563
Duke Energy Indiana
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	$ 11,727		$ 11,721
Generation facilities to be retired
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) \| MW	9,121
Public utilities, property, plant and equipment, net	$ 6,253
Generation facilities to be retired \| Duke Energy Carolinas \| Allen Steam Station Units 1-2
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) \| MW	334
Public utilities, property, plant and equipment, net	$ 21
Generation facilities to be retired \| Duke Energy Carolinas \| Allen Steam Station Units 4-5
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) \| MW	526
Public utilities, property, plant and equipment, net	$ 388
Generation facilities to be retired \| Duke Energy Carolinas \| Cliffside Unit 5
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) \| MW	546
Public utilities, property, plant and equipment, net	$ 343
Generation facilities to be retired \| Duke Energy Carolinas \| Allen Steam Station 3
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) \| MW	270
Public utilities, property, plant and equipment, net	$ 26
Generation facilities to be retired \| Duke Energy Progress \| Mayo Unit 1
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) \| MW	746
Public utilities, property, plant and equipment, net	$ 660
Generation facilities to be retired \| Duke Energy Progress \| Roxboro Units 3-4
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) \| MW	1,409
Public utilities, property, plant and equipment, net	$ 478
Generation facilities to be retired \| Duke Energy Florida \| Crystal River Units 4-5
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) \| MW	1,430
Public utilities, property, plant and equipment, net	$ 1,683
Generation facilities to be retired \| Duke Energy Florida \| Crystal River Units 4 and 5 \| Forecast
Public Utilities, General Disclosures [Line Items]
Facilities retiring ahead of schedule \| asset		2
Facilities retiring ahead of schedule, years ahead		8 years
Generation facilities to be retired \| Duke Energy Indiana \| Gallagher Units 2 and 4
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) \| MW	280
Public utilities, property, plant and equipment, net	$ 91
Generation facilities to be retired \| Duke Energy Indiana \| Gibson Units 1-5
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) \| MW	2,845
Public utilities, property, plant and equipment, net	$ 1,834
Generation facilities to be retired \| Duke Energy Indiana \| Cayuga Units 1-2
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) \| MW	1,005
Public utilities, property, plant and equipment, net	$ 755

Commitments and Contingencies_2

Commitments and Contingencies (Schedule of Environmental Loss Contingencies) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Environmental Matters Details [Line Items]
Reserves for Environmental Remediation	$ 74	$ 75
Environmental exit costs, reasonably possible additional loss	20
Duke Energy Carolinas
Environmental Matters Details [Line Items]
Reserves for Environmental Remediation	18	19
Environmental exit costs, reasonably possible additional loss	12
Progress Energy
Environmental Matters Details [Line Items]
Reserves for Environmental Remediation	18	19
Duke Energy Progress
Environmental Matters Details [Line Items]
Reserves for Environmental Remediation	6	6
Duke Energy Florida
Environmental Matters Details [Line Items]
Reserves for Environmental Remediation	12	12
Duke Energy Ohio
Environmental Matters Details [Line Items]
Reserves for Environmental Remediation	21	22
Environmental exit costs, reasonably possible additional loss	4
Duke Energy Indiana
Environmental Matters Details [Line Items]
Reserves for Environmental Remediation	5	6
Piedmont
Environmental Matters Details [Line Items]
Reserves for Environmental Remediation	$ 11	$ 10

Commitments and Contingencies_3

Commitments and Contingencies (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021USD ($)caseplantclaim	Dec. 31, 2020USD ($)
Texas Storm Uri Tort Litigation
Loss Contingencies [Line Items]
Number of state court actions filed \| case	15
Number of pending federal court cases \| case	1
Coal Ash Insurance Coverage Litigation
Loss Contingencies [Line Items]
Number of NC and SC Plants with Ash Basins \| plant	15
Duke Energy Carolinas \| Asbestos-related Injuries and Damages Claims
Loss Contingencies [Line Items]
Asbestos-related injuries and damages reserves	$ 564	$ 572
Reinsurance retention policy, excess retention, amount reinsured	714
Probable insurance recoveries	$ 704	704
Duke Energy Carolinas \| Asbestos-related Injuries and Damages Claims \| Non-malignant cases
Loss Contingencies [Line Items]
Loss contingency, pending claims, number \| claim	126
Asbestos-related injuries and damages reserves	$ 31
Duke Energy Carolinas \| Asbestos-related Injuries and Damages Claims \| Malignant cases
Loss Contingencies [Line Items]
Loss contingency, pending claims, number \| claim	47
Asbestos-related injuries and damages reserves	$ 17
Duke Energy and Duke Energy Carolinas \| ASU 2016-13
Loss Contingencies [Line Items]
Reserve for credit losses for insurance receivables	$ 15	$ 15

Commitments and Contingencies_4

Commitments and Contingencies (Narrative 2) (Details) - Spent Nuclear Fuel Matters $ in Millions	Jun. 18, 2018USD ($)
Duke Energy Progress
Gain Contingencies [Line Items]
Gain contingency, unrecorded amount	$ 100
Duke Energy Florida
Gain Contingencies [Line Items]
Gain contingency, unrecorded amount	$ 200

Commitments and Contingencies_5

Commitments and Contingencies (Schedule of Legal Reserves) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Loss Contingencies [Line Items]
Reserves for legal matters	$ 65	$ 68
Duke Energy Carolinas
Loss Contingencies [Line Items]
Reserves for legal matters	3	2
Progress Energy
Loss Contingencies [Line Items]
Reserves for legal matters	57	61
Duke Energy Progress
Loss Contingencies [Line Items]
Reserves for legal matters	11	13
Duke Energy Florida
Loss Contingencies [Line Items]
Reserves for legal matters	26	28
Piedmont
Loss Contingencies [Line Items]
Reserves for legal matters	$ 1	$ 1

Debt and Credit Facilities (Sum

Debt and Credit Facilities (Summary of Debt Issuances) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Debt Instrument [Line Items]
Debt issuances	$ 350,000,000
Repayments of long-term debt	76,000,000	$ 292,000,000
Duke Energy (Parent)
Debt Instrument [Line Items]
Debt issuances	0
Duke Energy Carolinas
Debt Instrument [Line Items]
Debt issuances	0
Repayments of long-term debt	33,000,000	2,000,000
Duke Energy Progress
Debt Instrument [Line Items]
Debt issuances	0
Repayments of long-term debt	2,000,000	1,000,000
Duke Energy Florida
Debt Instrument [Line Items]
Debt issuances	0
Repayments of long-term debt	33,000,000	$ 282,000,000
Duke Energy Ohio
Debt Instrument [Line Items]
Debt issuances	0
Duke Energy Indiana
Debt Instrument [Line Items]
Debt issuances	0
Piedmont
Debt Instrument [Line Items]
Debt issuances	350,000,000
Unsecured Debt
Debt Instrument [Line Items]
Repayments of long-term debt	$ 160,000,000
Unsecured Debt \| March 2021
Debt Instrument [Line Items]
Interest Rate	2.50%
Debt issuances	$ 350,000,000
Unsecured Debt \| Duke Energy (Parent) \| March 2021
Debt Instrument [Line Items]
Debt issuances	0
Unsecured Debt \| Piedmont \| March 2021
Debt Instrument [Line Items]
Debt issuances	$ 350,000,000

Debt and Credit Facilities (S_2

Debt and Credit Facilities (Summary of Current Maturities of Long-term Debt) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 5,586	$ 4,238
Other debt obligations
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 723
Duke Energy (Parent) \| Unsecured Debt \| Debt maturing May 2021, floating interest rate
Debt Instrument [Line Items]
Interest Rate	0.698%
Current maturities of long-term debt	$ 500
Duke Energy (Parent) \| Unsecured Debt \| Debt maturing September 2021, 3.550% interest rate
Debt Instrument [Line Items]
Interest Rate	3.55%
Current maturities of long-term debt	$ 500
Duke Energy (Parent) \| Unsecured Debt \| Debt maturing September 2021, 1.800% interest rate
Debt Instrument [Line Items]
Interest Rate	1.80%
Current maturities of long-term debt	$ 750
Duke Energy (Parent) \| Unsecured Debt \| Debt Maturing March 2022, 3.227% interest rate
Debt Instrument [Line Items]
Interest Rate	3.227%
Current maturities of long-term debt	$ 300
Duke Energy (Parent) \| Unsecured Debt \| Debt Maturing March 2022 0.871%, floating interest rate
Debt Instrument [Line Items]
Interest Rate	0.827%
Current maturities of long-term debt	$ 300
Piedmont
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 160	160
Piedmont \| Unsecured Debt \| Debt maturing June 2021, 4.240% interest rate
Debt Instrument [Line Items]
Interest Rate	4.24%
Current maturities of long-term debt	$ 160
Duke Energy Florida
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 824	823
Duke Energy Florida \| Unsecured Debt \| Debt Maturing November 2021, 0.482% interest rate
Debt Instrument [Line Items]
Interest Rate	0.441%
Current maturities of long-term debt	$ 200
Duke Energy Florida \| First Mortgage Bonds \| Bonds maturing August 2021, 3.100% interest rate
Debt Instrument [Line Items]
Interest Rate	3.10%
Current maturities of long-term debt	$ 300
Duke Energy Carolinas
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 507	506
Duke Energy Carolinas \| First Mortgage Bonds \| Bonds maturing June 2021, 3.900% interest rate
Debt Instrument [Line Items]
Interest Rate	3.90%
Current maturities of long-term debt	$ 500
Duke Energy Progress
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 1,302	603
Duke Energy Progress \| Unsecured Debt \| Debt Maturing February 2022, 0.400%, floating interest rate
Debt Instrument [Line Items]
Interest Rate	0.369%
Current maturities of long-term debt	$ 700
Duke Energy Progress \| First Mortgage Bonds \| Debt maturing September 2021, 3.000% interest rate
Debt Instrument [Line Items]
Interest Rate	3.00%
Current maturities of long-term debt	$ 500
Duke Energy Progress \| First Mortgage Bonds \| Debt maturing September 2021, 8.625% interest rate
Debt Instrument [Line Items]
Interest Rate	8.625%
Current maturities of long-term debt	$ 100
Duke Energy Indiana
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 123	$ 70
Duke Energy Indiana \| First Mortgage Bonds \| Debt Maturing January 2022, 8.850% interest rate
Debt Instrument [Line Items]
Interest Rate	8.85%
Current maturities of long-term debt	$ 53

Debt and Credit Facilities (Nar

Debt and Credit Facilities (Narrative) (Details)	Mar. 31, 2021USD ($)tranche	Dec. 31, 2020USD ($)
Debt Instrument [Line Items]
Debt issuances	$ 350,000,000
Number of tranches \| tranche	2
Current maturities of long-term debt	$ 5,586,000,000	$ 4,238,000,000
Duke Energy Carolinas
Debt Instrument [Line Items]
Debt issuances	0
Current maturities of long-term debt	507,000,000	$ 506,000,000
Duke Energy Carolinas \| First Mortgage Bonds
Debt Instrument [Line Items]
Debt issuances	1,000,000,000
First Tranche \| Duke Energy Carolinas \| First Mortgage Bonds
Debt Instrument [Line Items]
Debt issuances	$ 550,000,000
Stated rate	2.55%
Second Tranche \| Duke Energy Carolinas \| First Mortgage Bonds
Debt Instrument [Line Items]
Debt issuances	$ 450,000,000
Stated rate	3.45%
Bonds maturing June 2021, 3.900% interest rate \| Duke Energy Carolinas \| First Mortgage Bonds
Debt Instrument [Line Items]
Stated rate	3.90%
Current maturities of long-term debt	$ 500,000,000

Debt and Credit Facilities (Sch

Debt and Credit Facilities (Schedule of Line of Credit Facilities) (Details) - Master Credit Facility	Mar. 31, 2021USD ($)
Line of Credit Facility [Line Items]
Facility size	$ 8,000,000,000
Commercial paper	(3,466,000,000)
Outstanding letters of credit	(31,000,000)
Tax-exempt bonds	(81,000,000)
Available capacity under the Master Credit Facility	4,422,000,000
Duke Energy Carolinas
Line of Credit Facility [Line Items]
Facility size	1,475,000,000
Commercial paper	(741,000,000)
Outstanding letters of credit	(4,000,000)
Available capacity under the Master Credit Facility	730,000,000
Duke Energy Progress
Line of Credit Facility [Line Items]
Facility size	1,250,000,000
Commercial paper	(292,000,000)
Outstanding letters of credit	(2,000,000)
Available capacity under the Master Credit Facility	956,000,000
Duke Energy Florida
Line of Credit Facility [Line Items]
Facility size	700,000,000
Commercial paper	(243,000,000)
Available capacity under the Master Credit Facility	457,000,000
Duke Energy Ohio
Line of Credit Facility [Line Items]
Facility size	625,000,000
Commercial paper	(259,000,000)
Available capacity under the Master Credit Facility	366,000,000
Duke Energy Indiana
Line of Credit Facility [Line Items]
Facility size	600,000,000
Commercial paper	(150,000,000)
Tax-exempt bonds	(81,000,000)
Available capacity under the Master Credit Facility	369,000,000
Piedmont
Line of Credit Facility [Line Items]
Facility size	700,000,000
Available capacity under the Master Credit Facility	700,000,000
Duke Energy (Parent) \| Proceeds loaned to subsidiary registrants
Line of Credit Facility [Line Items]
Commercial paper	(625,000,000)
Duke Energy (Parent) \| Duke Energy (Parent)
Line of Credit Facility [Line Items]
Facility size	2,650,000,000
Commercial paper	(1,781,000,000)
Outstanding letters of credit	(25,000,000)
Available capacity under the Master Credit Facility	$ 844,000,000

Debt and Credit Facilities (S_3

Debt and Credit Facilities (Schedule of Other Credit Facilities) (Details) - Master Credit Facility	3 Months Ended
	Mar. 31, 2021USD ($)
Line of Credit Facility [Line Items]
Facility size	$ 8,000,000,000
Duke Energy (Parent) Three-Year Revolving Credit Facility \| Duke Energy (Parent)
Line of Credit Facility [Line Items]
Facility size	1,000,000,000
Amount drawn	$ 500,000,000
Facility term	3 years

Goodwill (Rollforward of Goodwi

Goodwill (Rollforward of Goodwill) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Goodwill [Line Items]
Goodwill balance	$ 19,425	$ 19,425
Accumulated impairment charges	(122)	(122)
Goodwill, adjusted for accumulated impairment charges	19,303	19,303
Electric Utilities and Infrastructure
Goodwill [Line Items]
Goodwill balance	17,379	17,379
Accumulated impairment charges	0	0
Goodwill, adjusted for accumulated impairment charges	17,379	17,379
Gas Utilities and Infrastructure
Goodwill [Line Items]
Goodwill balance	1,924	1,924
Accumulated impairment charges	0	0
Goodwill, adjusted for accumulated impairment charges	1,924	1,924
Commercial Renewables
Goodwill [Line Items]
Goodwill balance	122	122
Accumulated impairment charges	(122)	(122)
Goodwill, adjusted for accumulated impairment charges	$ 0	$ 0

Goodwill (Narrative) (Details)

Goodwill (Narrative) (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Goodwill [Line Items]
Goodwill	$ 19,303,000,000	$ 19,303,000,000
Accumulated impairment charges	122,000,000	122,000,000
Electric Utilities and Infrastructure
Goodwill [Line Items]
Goodwill	17,379,000,000	17,379,000,000
Accumulated impairment charges	0	0
Gas Utilities and Infrastructure
Goodwill [Line Items]
Goodwill	1,924,000,000	1,924,000,000
Accumulated impairment charges	0	0
Duke Energy Ohio
Goodwill [Line Items]
Goodwill	920,000,000	920,000,000
Accumulated impairment charges	216,000,000	216,000,000
Duke Energy Ohio \| Electric Utilities and Infrastructure
Goodwill [Line Items]
Goodwill	596,000,000	596,000,000
Duke Energy Ohio \| Gas Utilities and Infrastructure
Goodwill [Line Items]
Goodwill	324,000,000	324,000,000
Progress Energy
Goodwill [Line Items]
Goodwill	3,655,000,000	3,655,000,000
Progress Energy \| Electric Utilities and Infrastructure
Goodwill [Line Items]
Accumulated impairment charges	0	0
Piedmont
Goodwill [Line Items]
Goodwill	49,000,000	49,000,000
Piedmont \| Gas Utilities and Infrastructure
Goodwill [Line Items]
Accumulated impairment charges	$ 0	$ 0

Related Party Transactions (Oth

Related Party Transactions (Other Revenue and Expense) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Duke Energy Carolinas \| Corporate governance and shared service expenses \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$ 203	$ 134
Duke Energy Carolinas \| Indemnification coverages \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	6	5
Duke Energy Carolinas \| JDA \| Duke Energy Progress
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	40	24
Related party transaction, other revenues from transactions with related party	13	7
Duke Energy Carolinas \| Intercompany natural gas purchases and sales \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	14	6
Progress Energy \| Corporate governance and shared service expenses \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	181	146
Progress Energy \| Indemnification coverages \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	10	9
Progress Energy \| JDA \| Duke Energy Carolinas
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	13	7
Related party transaction, other revenues from transactions with related party	40	24
Progress Energy \| Intercompany natural gas purchases and sales \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	19	19
Duke Energy Progress \| Corporate governance and shared service expenses \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	105	75
Duke Energy Progress \| Indemnification coverages \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	5	4
Duke Energy Progress \| JDA \| Duke Energy Carolinas
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	13	7
Related party transaction, other revenues from transactions with related party	40	24
Duke Energy Progress \| Intercompany natural gas purchases and sales \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	19	19
Duke Energy Florida \| Corporate governance and shared service expenses \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	76	71
Duke Energy Florida \| Indemnification coverages \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	5	5
Duke Energy Ohio \| Corporate governance and shared service expenses \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	79	84
Duke Energy Ohio \| Indemnification coverages \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	1	1
Duke Energy Indiana \| Corporate governance and shared service expenses \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	113	106
Duke Energy Indiana \| Indemnification coverages \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	2	2
Piedmont \| Corporate governance and shared service expenses \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	33	34
Piedmont \| Indemnification coverages \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	1	1
Piedmont \| Intercompany natural gas purchases and sales \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	33	25
Piedmont \| Natural gas storage and transportation costs \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$ 6	$ 6

Related Party Transactions (Int

Related Party Transactions (Intercompany Income Taxes) (Details) - Affiliated Entity - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Duke Energy Carolinas
Related Party Transaction [Line Items]
Intercompany income tax payable	$ 31	$ 31
Progress Energy
Related Party Transaction [Line Items]
Intercompany income tax receivable	84
Intercompany income tax payable		33
Duke Energy Progress
Related Party Transaction [Line Items]
Intercompany income tax payable	12	46
Duke Energy Florida
Related Party Transaction [Line Items]
Intercompany income tax receivable	46
Intercompany income tax payable		35
Duke Energy Ohio
Related Party Transaction [Line Items]
Intercompany income tax payable	2	2
Duke Energy Indiana
Related Party Transaction [Line Items]
Intercompany income tax receivable		9
Intercompany income tax payable	36
Piedmont
Related Party Transaction [Line Items]
Intercompany income tax receivable		$ 10
Intercompany income tax payable	$ 39

Derivatives and Hedging (Notion

Derivatives and Hedging (Notional Amounts of Derivative Instruments) (Details) Mcf in Millions, $ in Millions	3 Months Ended	6 Months Ended	12 Months Ended
	Mar. 31, 2021USD ($)GWhMcf	Jun. 30, 2020GWhMcf	Dec. 31, 2020USD ($)GWh
Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 3,361		$ 1,809
Commodity contracts \| Cash flow hedges
Derivative [Line Items]
Notional amount, energy measure (in gigawatt-hours) \| GWh	10,720		22,048
Commodity contracts \| Electricity (GWh)(a)
Derivative [Line Items]
Notional amount, energy measure (in gigawatt-hours) \| GWh	16,259	35,409
Commodity contracts \| Natural gas (millions of dekatherms)
Derivative [Line Items]
Notional amount, volume (in millions of dekatherms) \| Mcf	675	678
Designated contracts \| Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 1,630		$ 632
Designated contracts \| Interest Rate Contracts \| VIE primary beneficiary
Derivative [Line Items]
Notional amount	631		632
Undesignated contracts \| Interest Rate Contracts
Derivative [Line Items]
Notional amount	1,731		1,177
Undesignated contracts \| Interest Rate Contracts \| VIE primary beneficiary
Derivative [Line Items]
Notional amount	54
Duke Energy Carolinas \| Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 400		400
Duke Energy Carolinas \| Commodity contracts \| Natural gas (millions of dekatherms)
Derivative [Line Items]
Notional amount, volume (in millions of dekatherms) \| Mcf	151	145
Duke Energy Carolinas \| Undesignated contracts \| Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 400		400
Progress Energy \| Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 1,250		750
Progress Energy \| Commodity contracts \| Natural gas (millions of dekatherms)
Derivative [Line Items]
Notional amount, volume (in millions of dekatherms) \| Mcf	158	158
Progress Energy \| Undesignated contracts \| Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 1,250		750
Duke Energy Progress \| Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 750		750
Duke Energy Progress \| Commodity contracts \| Natural gas (millions of dekatherms)
Derivative [Line Items]
Notional amount, volume (in millions of dekatherms) \| Mcf	158	158
Duke Energy Progress \| Undesignated contracts \| Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 750		750
Duke Energy Florida \| Interest Rate Contracts
Derivative [Line Items]
Notional amount	500
Duke Energy Florida \| Undesignated contracts \| Interest Rate Contracts
Derivative [Line Items]
Notional amount	500
Duke Energy Ohio \| Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 27		27
Duke Energy Ohio \| Commodity contracts \| Electricity (GWh)(a)
Derivative [Line Items]
Notional amount, energy measure (in gigawatt-hours) \| GWh	1,325	2,559
Duke Energy Ohio \| Undesignated contracts \| Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 27		$ 27
Duke Energy Indiana \| Commodity contracts \| Electricity (GWh)(a)
Derivative [Line Items]
Notional amount, energy measure (in gigawatt-hours) \| GWh	4,214	10,802
Duke Energy Indiana \| Commodity contracts \| Natural gas (millions of dekatherms)
Derivative [Line Items]
Notional amount, volume (in millions of dekatherms) \| Mcf	2	2
Piedmont \| Commodity contracts \| Natural gas (millions of dekatherms)
Derivative [Line Items]
Notional amount, volume (in millions of dekatherms) \| Mcf	364	373

Derivatives and Hedging (Locati

Derivatives and Hedging (Location and Fair Value Amounts of Derivatives Reflected in the Condensed Consolidated Balance Sheets) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	$ 206	$ 61
Location and fair value amounts of derivatives (Liability)	349	324
Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	192	48
Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	14	13
Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	57	64
Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	292	260
Commodity Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	46	43
Location and fair value amounts of derivatives (Liability)	301	251
Interest Rate Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	160	18
Location and fair value amounts of derivatives (Liability)	48	73
Not Designated as Hedging Instruments \| Commodity Contracts \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	32	30
Not Designated as Hedging Instruments \| Commodity Contracts \| Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	14	13
Not Designated as Hedging Instruments \| Commodity Contracts \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	19	30
Not Designated as Hedging Instruments \| Commodity Contracts \| Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	154	137
Not Designated as Hedging Instruments \| Interest Rate Contracts \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	129	18
Not Designated as Hedging Instruments \| Interest Rate Contracts \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	4	5
Not Designated as Hedging Instruments \| Interest Rate Contracts \| Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	4	5
Designated as Hedging Instruments \| Commodity Contracts \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	19	14
Designated as Hedging Instruments \| Commodity Contracts \| Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	109	70
Designated as Hedging Instruments \| Interest Rate Contracts \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	31
Designated as Hedging Instruments \| Interest Rate Contracts \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	15	15
Designated as Hedging Instruments \| Interest Rate Contracts \| Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	25	48
Duke Energy Carolinas
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	62	20
Location and fair value amounts of derivatives (Liability)		20
Duke Energy Carolinas \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	55	14
Duke Energy Carolinas \| Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	6
Duke Energy Carolinas \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		17
Duke Energy Carolinas \| Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		3
Duke Energy Carolinas \| Commodity Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	24	20
Location and fair value amounts of derivatives (Liability)		16
Duke Energy Carolinas \| Interest Rate Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	38
Location and fair value amounts of derivatives (Liability)		4
Duke Energy Carolinas \| Not Designated as Hedging Instruments \| Commodity Contracts \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	17	14
Duke Energy Carolinas \| Not Designated as Hedging Instruments \| Commodity Contracts \| Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	6
Duke Energy Carolinas \| Not Designated as Hedging Instruments \| Commodity Contracts \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		13
Duke Energy Carolinas \| Not Designated as Hedging Instruments \| Commodity Contracts \| Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		3
Duke Energy Carolinas \| Not Designated as Hedging Instruments \| Interest Rate Contracts \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	38
Duke Energy Carolinas \| Not Designated as Hedging Instruments \| Interest Rate Contracts \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		4
Progress Energy
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	103	33
Location and fair value amounts of derivatives (Liability)	28	29
Progress Energy \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	96	27
Progress Energy \| Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	6
Progress Energy \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	3	2
Progress Energy \| Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	25	27
Progress Energy \| Commodity Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	19	15
Location and fair value amounts of derivatives (Liability)	25	29
Progress Energy \| Interest Rate Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	84	18
Location and fair value amounts of derivatives (Liability)	3
Progress Energy \| Not Designated as Hedging Instruments \| Commodity Contracts \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	12	9
Progress Energy \| Not Designated as Hedging Instruments \| Commodity Contracts \| Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	6
Progress Energy \| Not Designated as Hedging Instruments \| Commodity Contracts \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		2
Progress Energy \| Not Designated as Hedging Instruments \| Commodity Contracts \| Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	25	27
Progress Energy \| Not Designated as Hedging Instruments \| Interest Rate Contracts \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	84	18
Progress Energy \| Not Designated as Hedging Instruments \| Interest Rate Contracts \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	3
Duke Energy Progress
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	100	33
Location and fair value amounts of derivatives (Liability)	9	14
Duke Energy Progress \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	93	27
Duke Energy Progress \| Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	6
Duke Energy Progress \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		2
Duke Energy Progress \| Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	9	12
Duke Energy Progress \| Commodity Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	19	15
Location and fair value amounts of derivatives (Liability)	9	14
Duke Energy Progress \| Interest Rate Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	81	18
Duke Energy Progress \| Not Designated as Hedging Instruments \| Commodity Contracts \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	12	9
Duke Energy Progress \| Not Designated as Hedging Instruments \| Commodity Contracts \| Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	6
Duke Energy Progress \| Not Designated as Hedging Instruments \| Commodity Contracts \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		2
Duke Energy Progress \| Not Designated as Hedging Instruments \| Commodity Contracts \| Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	9	12
Duke Energy Progress \| Not Designated as Hedging Instruments \| Interest Rate Contracts \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	81	18
Duke Energy Florida
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3
Location and fair value amounts of derivatives (Liability)	3
Duke Energy Florida \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3
Duke Energy Florida \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	3
Duke Energy Florida \| Interest Rate Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3
Location and fair value amounts of derivatives (Liability)	3
Duke Energy Florida \| Not Designated as Hedging Instruments \| Interest Rate Contracts \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3
Duke Energy Florida \| Not Designated as Hedging Instruments \| Interest Rate Contracts \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	3
Duke Energy Ohio
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		1
Location and fair value amounts of derivatives (Liability)	5	6
Duke Energy Ohio \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		1
Duke Energy Ohio \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	1
Duke Energy Ohio \| Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	4	5
Duke Energy Ohio \| Commodity Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		1
Duke Energy Ohio \| Interest Rate Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	5	6
Duke Energy Ohio \| Not Designated as Hedging Instruments \| Commodity Contracts \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		1
Duke Energy Ohio \| Not Designated as Hedging Instruments \| Interest Rate Contracts \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	1
Duke Energy Ohio \| Not Designated as Hedging Instruments \| Interest Rate Contracts \| Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	4	5
Duke Energy Indiana
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	6
Location and fair value amounts of derivatives (Liability)		1
Duke Energy Indiana \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	6
Duke Energy Indiana \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		1
Duke Energy Indiana \| Commodity Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	6
Location and fair value amounts of derivatives (Liability)		1
Duke Energy Indiana \| Not Designated as Hedging Instruments \| Commodity Contracts \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	6
Duke Energy Indiana \| Not Designated as Hedging Instruments \| Commodity Contracts \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		1
Piedmont
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	1
Location and fair value amounts of derivatives (Liability)	148	122
Piedmont \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	1
Piedmont \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	19	15
Piedmont \| Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	129	107
Piedmont \| Commodity Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	1
Location and fair value amounts of derivatives (Liability)	148	122
Piedmont \| Not Designated as Hedging Instruments \| Commodity Contracts \| Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	1
Piedmont \| Not Designated as Hedging Instruments \| Commodity Contracts \| Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	19	15
Piedmont \| Not Designated as Hedging Instruments \| Commodity Contracts \| Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	$ 129	$ 107

Derivatives and Hedging (Schedu

Derivatives and Hedging (Schedule of Offsetting Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	$ 206	$ 61
Net amounts recognized on the Condensed Consolidated Balance Sheet	206	61
Current assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	192	48
Gross amounts offset		(3)
Net amounts recognized on the Condensed Consolidated Balance Sheet	192	45
Noncurrent assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	14	13
Gross amounts offset	(4)	(5)
Net amounts recognized on the Condensed Consolidated Balance Sheet	10	8
Duke Energy Carolinas
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	62	20
Net amounts recognized on the Condensed Consolidated Balance Sheet	62	20
Duke Energy Carolinas \| Current assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	55	14
Gross amounts offset		(2)
Net amounts recognized on the Condensed Consolidated Balance Sheet	55	12
Duke Energy Carolinas \| Noncurrent assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	7	6
Gross amounts offset		(1)
Net amounts recognized on the Condensed Consolidated Balance Sheet	7	5
Progress Energy
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	103	33
Net amounts recognized on the Condensed Consolidated Balance Sheet	103	33
Progress Energy \| Current assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	96	27
Gross amounts offset		(2)
Net amounts recognized on the Condensed Consolidated Balance Sheet	96	25
Progress Energy \| Noncurrent assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	7	6
Gross amounts offset	(4)	(4)
Net amounts recognized on the Condensed Consolidated Balance Sheet	3	2
Duke Energy Progress
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	100	33
Net amounts recognized on the Condensed Consolidated Balance Sheet	100	33
Duke Energy Progress \| Current assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	93	27
Gross amounts offset		(2)
Net amounts recognized on the Condensed Consolidated Balance Sheet	93	25
Duke Energy Progress \| Noncurrent assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	7	6
Gross amounts offset	(4)	(4)
Net amounts recognized on the Condensed Consolidated Balance Sheet	3	2
Duke Energy Florida
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	3
Net amounts recognized on the Condensed Consolidated Balance Sheet	3
Duke Energy Florida \| Current assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	3
Net amounts recognized on the Condensed Consolidated Balance Sheet	3
Duke Energy Ohio
Offsetting Derivative Assets [Abstract]
Gross amounts recognized		1
Duke Energy Ohio \| Current assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized		1
Net amounts recognized on the Condensed Consolidated Balance Sheet		1
Duke Energy Indiana
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	2	6
Net amounts recognized on the Condensed Consolidated Balance Sheet	2	6
Duke Energy Indiana \| Current assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	2	6
Net amounts recognized on the Condensed Consolidated Balance Sheet	2	6
Piedmont
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	1	1
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	1
Piedmont \| Current assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	1	1
Net amounts recognized on the Condensed Consolidated Balance Sheet	$ 1	$ 1

Derivatives and Hedging (Sche_2

Derivatives and Hedging (Schedule of Offsetting Liabilities) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	$ 349	$ 324
Net amounts recognized on the Condensed Consolidated Balance Sheet	349	324
Current liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	57	64
Gross amounts offset		(3)
Net amounts recognized on the Condensed Consolidated Balance Sheet	57	61
Noncurrent liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	292	260
Gross amounts offset	(4)	(5)
Net amounts recognized on the Condensed Consolidated Balance Sheet	288	255
Duke Energy Carolinas
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized		20
Net amounts recognized on the Condensed Consolidated Balance Sheet		20
Duke Energy Carolinas \| Current liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized		17
Gross amounts offset		(2)
Net amounts recognized on the Condensed Consolidated Balance Sheet		15
Duke Energy Carolinas \| Noncurrent liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized		3
Gross amounts offset		(1)
Net amounts recognized on the Condensed Consolidated Balance Sheet		2
Progress Energy
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	28	29
Net amounts recognized on the Condensed Consolidated Balance Sheet	28	29
Progress Energy \| Current liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	3	2
Gross amounts offset		(2)
Net amounts recognized on the Condensed Consolidated Balance Sheet	3
Progress Energy \| Noncurrent liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	25	27
Gross amounts offset	(4)	(4)
Net amounts recognized on the Condensed Consolidated Balance Sheet	21	23
Duke Energy Progress
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	9	14
Net amounts recognized on the Condensed Consolidated Balance Sheet	9	14
Duke Energy Progress \| Current liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized		2
Gross amounts offset		(2)
Duke Energy Progress \| Noncurrent liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	9	12
Gross amounts offset	(4)	(4)
Net amounts recognized on the Condensed Consolidated Balance Sheet	5	8
Duke Energy Florida
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	3
Net amounts recognized on the Condensed Consolidated Balance Sheet	3
Duke Energy Florida \| Current liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	3
Net amounts recognized on the Condensed Consolidated Balance Sheet	3
Duke Energy Ohio
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	5	6
Duke Energy Ohio \| Current liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	1	1
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	1
Duke Energy Ohio \| Noncurrent liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	4	5
Net amounts recognized on the Condensed Consolidated Balance Sheet	4	5
Duke Energy Indiana
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized		1
Net amounts recognized on the Condensed Consolidated Balance Sheet		1
Duke Energy Indiana \| Current liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized		1
Net amounts recognized on the Condensed Consolidated Balance Sheet		1
Piedmont
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	148	122
Net amounts recognized on the Condensed Consolidated Balance Sheet	148	122
Piedmont \| Current liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	19	15
Net amounts recognized on the Condensed Consolidated Balance Sheet	19	15
Piedmont \| Noncurrent liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	129	107
Net amounts recognized on the Condensed Consolidated Balance Sheet	$ 129	$ 107

Investments in Debt and Equit_3

Investments in Debt and Equity Securities (Estimated Fair Value of Investments in Debt and Equity Securities) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale
Estimated Fair Value	$ 3,112
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	4,541	$ 4,387
Unrealized Holding Losses	77	55
Estimated Fair Value	10,060	9,687
Duke Energy Carolinas
Debt Securities, Available-for-sale
Estimated Fair Value	1,344
Progress Energy
Debt Securities, Available-for-sale
Estimated Fair Value	1,517
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	1,878	1,769
Unrealized Holding Losses	37	31
Estimated Fair Value	4,395	4,296
Duke Energy Progress
Debt Securities, Available-for-sale
Estimated Fair Value	1,003
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	1,790	1,687
Unrealized Holding Losses	32	31
Estimated Fair Value	3,646	3,529
Duke Energy Florida
Debt Securities, Available-for-sale
Estimated Fair Value	514
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	88	82
Unrealized Holding Losses	5
Estimated Fair Value	645	663
Duke Energy Indiana
Debt Securities, Available-for-sale
Estimated Fair Value	45
NDTF
Available-for-sale Securities
Cash and cash equivalents	193	177
Equity Securities, FV-NI
Equity Securities, FV-NI, Accumulated Unrealized Gain	4,363	4,138
Equity Securities, FV-NI, Accumulated Unrealized Loss	47	54
Equity securities, FV-NI	6,379	6,235
Debt Securities, Available-for-sale
Estimated Fair Value	2,835	2,717
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	4,450	4,295
Unrealized Holding Losses	74	55
Estimated Fair Value	9,407	9,129
NDTF \| Duke Energy Carolinas
Available-for-sale Securities
Cash and cash equivalents	63	30
Equity Securities, FV-NI
Equity Securities, FV-NI, Accumulated Unrealized Gain	2,531	2,442
Equity Securities, FV-NI, Accumulated Unrealized Loss	23	23
Equity securities, FV-NI	3,738	3,685
Debt Securities, Available-for-sale
Estimated Fair Value	1,344	1,250
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	2,574	2,529
Unrealized Holding Losses	37	24
Estimated Fair Value	5,145	4,965
NDTF \| Progress Energy
Available-for-sale Securities
Cash and cash equivalents	130	147
Equity Securities, FV-NI
Equity Securities, FV-NI, Accumulated Unrealized Gain	1,832	1,696
Equity Securities, FV-NI, Accumulated Unrealized Loss	24	31
Equity securities, FV-NI	2,641	2,550
Debt Securities, Available-for-sale
Estimated Fair Value	1,491	1,467
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	1,876	1,766
Unrealized Holding Losses	37	31
Estimated Fair Value	4,262	4,164
NDTF \| Duke Energy Progress
Available-for-sale Securities
Cash and cash equivalents	95	76
Equity Securities, FV-NI
Equity Securities, FV-NI, Accumulated Unrealized Gain	1,746	1,617
Equity Securities, FV-NI, Accumulated Unrealized Loss	24	31
Equity securities, FV-NI	2,547	2,459
Debt Securities, Available-for-sale
Estimated Fair Value	1,003	993
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	1,790	1,687
Unrealized Holding Losses	32	31
Estimated Fair Value	3,645	3,528
NDTF \| Duke Energy Florida
Available-for-sale Securities
Cash and cash equivalents	35	71
Equity Securities, FV-NI
Equity Securities, FV-NI, Accumulated Unrealized Gain	86	79
Equity securities, FV-NI	94	91
Debt Securities, Available-for-sale
Estimated Fair Value	488	474
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	86	79
Unrealized Holding Losses	5
Estimated Fair Value	617	636
Other Investments
Available-for-sale Securities
Cash and cash equivalents	222	127
Equity Securities, FV-NI
Equity Securities, FV-NI, Accumulated Unrealized Gain	86	79
Equity securities, FV-NI	154	146
Debt Securities, Available-for-sale
Estimated Fair Value	277	285
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	91	92
Unrealized Holding Losses	3
Estimated Fair Value	653	558
Other Investments \| Progress Energy
Available-for-sale Securities
Cash and cash equivalents	107	106
Debt Securities, Available-for-sale
Estimated Fair Value	26	26
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	2	3
Estimated Fair Value	133	132
Other Investments \| Duke Energy Progress
Available-for-sale Securities
Cash and cash equivalents	1	1
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Estimated Fair Value	1	1
Other Investments \| Duke Energy Florida
Available-for-sale Securities
Cash and cash equivalents	2	1
Debt Securities, Available-for-sale
Estimated Fair Value	26	26
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	2	3
Estimated Fair Value	28	27
Other Investments \| Duke Energy Indiana
Available-for-sale Securities
Cash and cash equivalents		1
Equity Securities, FV-NI
Equity Securities, FV-NI, Accumulated Unrealized Gain	62	58
Equity securities, FV-NI	102	97
Debt Securities, Available-for-sale
Estimated Fair Value	45	45
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	63	59
Unrealized Holding Losses	1
Estimated Fair Value	147	143
Corporate debt securities \| NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	38	76
Gross Unrealized Holding Losses	8	1
Estimated Fair Value	793	806
Corporate debt securities \| NDTF \| Duke Energy Carolinas
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	23	49
Gross Unrealized Holding Losses	5	1
Estimated Fair Value	475	510
Corporate debt securities \| NDTF \| Progress Energy
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	15	27
Gross Unrealized Holding Losses	3
Estimated Fair Value	318	296
Corporate debt securities \| NDTF \| Duke Energy Progress
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	15	27
Gross Unrealized Holding Losses	3
Estimated Fair Value	291	296
Corporate debt securities \| NDTF \| Duke Energy Florida
Debt Securities, Available-for-sale
Estimated Fair Value	27
Corporate debt securities \| Other Investments
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	2	8
Estimated Fair Value	109	110
Corporate debt securities \| Other Investments \| Duke Energy Indiana
Debt Securities, Available-for-sale
Estimated Fair Value	4	3
Municipal bonds \| NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	13	22
Gross Unrealized Holding Losses	1
Estimated Fair Value	299	370
Municipal bonds \| NDTF \| Duke Energy Carolinas
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains		6
Estimated Fair Value	22	91
Municipal bonds \| NDTF \| Progress Energy
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	13	16
Gross Unrealized Holding Losses	1
Estimated Fair Value	277	279
Municipal bonds \| NDTF \| Duke Energy Progress
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	13	16
Gross Unrealized Holding Losses	1
Estimated Fair Value	277	279
Municipal bonds \| Other Investments
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	3	5
Gross Unrealized Holding Losses	1
Estimated Fair Value	77	86
Municipal bonds \| Other Investments \| Progress Energy
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	2	3
Estimated Fair Value	26	26
Municipal bonds \| Other Investments \| Duke Energy Florida
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	2	3
Estimated Fair Value	26	26
Municipal bonds \| Other Investments \| Duke Energy Indiana
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	1	1
Gross Unrealized Holding Losses	1
Estimated Fair Value	35	38
U.S. government bonds \| NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	31	51
Gross Unrealized Holding Losses	18
Estimated Fair Value	1,559	1,361
U.S. government bonds \| NDTF \| Duke Energy Carolinas
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	16	25
Gross Unrealized Holding Losses	9
Estimated Fair Value	669	475
U.S. government bonds \| NDTF \| Progress Energy
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	15	26
Gross Unrealized Holding Losses	9
Estimated Fair Value	890	886
U.S. government bonds \| NDTF \| Duke Energy Progress
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	15	26
Gross Unrealized Holding Losses	4
Estimated Fair Value	429	412
U.S. government bonds \| NDTF \| Duke Energy Florida
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	5
Estimated Fair Value	461	474
U.S. government bonds \| Other Investments
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	1
Estimated Fair Value	55	42
U.S. government bonds \| Other Investments \| Duke Energy Indiana
Debt Securities, Available-for-sale
Estimated Fair Value	6	4
Other debt securities \| NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	5	8
Estimated Fair Value	184	180
Other debt securities \| NDTF \| Duke Energy Carolinas
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	4	7
Estimated Fair Value	178	174
Other debt securities \| NDTF \| Progress Energy
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	1	1
Estimated Fair Value	6	6
Other debt securities \| NDTF \| Duke Energy Progress
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	1	1
Estimated Fair Value	6	6
Other debt securities \| Other Investments
Debt Securities, Available-for-sale
Gross Unrealized Holding Losses	1
Estimated Fair Value	$ 36	$ 47

Investments in Debt and Equit_4

Investments in Debt and Equity Securities (Realized Gains and Losses) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
FV-NI:
Realized gains	$ 140	$ 23
Realized losses	23	65
AFS:
Realized gains	18	20
Realized losses	13	6
Duke Energy Carolinas
FV-NI:
Realized gains	128	9
Realized losses	16	45
AFS:
Realized gains	13	12
Realized losses	9	5
Progress Energy
FV-NI:
Realized gains	12	14
Realized losses	7	20
AFS:
Realized gains	4	5
Realized losses	3	1
Duke Energy Progress
FV-NI:
Realized gains	12	14
Realized losses	7	20
AFS:
Realized gains	4	5
Realized losses	$ 3	$ 1

Investments in Debt and Equit_5

Investments in Debt and Equity Securities (Maturities) (Details) $ in Millions	Mar. 31, 2021USD ($)
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	$ 152
Due after one through five years	1,013
Due after five through 10 years	693
Due after 10 years	1,254
Total	3,112
Duke Energy Carolinas
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	7
Due after one through five years	375
Due after five through 10 years	310
Due after 10 years	652
Total	1,344
Progress Energy
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	116
Due after one through five years	579
Due after five through 10 years	289
Due after 10 years	533
Total	1,517
Duke Energy Progress
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	18
Due after one through five years	267
Due after five through 10 years	217
Due after 10 years	501
Total	1,003
Duke Energy Florida
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	98
Due after one through five years	312
Due after five through 10 years	72
Due after 10 years	32
Total	514
Duke Energy Indiana
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	5
Due after one through five years	18
Due after five through 10 years	9
Due after 10 years	13
Total	$ 45

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value Measurement Amounts for Assets and Liabilities) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	$ 3,112
Derivative assets	206	$ 61
Total assets	10,266	9,748
Derivative liabilities	(349)	(324)
Net assets (liabilities)	9,917	9,424
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	1	1
Total assets	7,970	7,551
Net assets (liabilities)	7,970	7,551
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	203	53
Total assets	2,247	2,144
Derivative liabilities	(221)	(240)
Net assets (liabilities)	2,026	1,904
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	2	7
Total assets	2	7
Derivative liabilities	(128)	(84)
Net assets (liabilities)	(126)	(77)
Not Categorized
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	47	46
Net assets (liabilities)	47	46
NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	193	177
Equity securities, FV-NI	6,379	6,235
Debt securities, available-for-sale	2,835	2,717
NDTF \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	193	177
Debt securities, available-for-sale	1,019	874
NDTF \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	1,816	1,843
NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	6,379	6,235
NDTF equity securities \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	6,332	6,189
NDTF equity securities \| Not Categorized
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	47	46
Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	222	127
Equity securities, FV-NI	154	146
Debt securities, available-for-sale	277	285
Other Investments \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	222	127
Equity securities, FV-NI	154	146
Debt securities, available-for-sale	49	37
Other Investments \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	228	248
Duke Energy Carolinas
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	1,344
Derivative assets	62	20
Total assets	5,207	4,985
Derivative liabilities		(20)
Net assets (liabilities)		4,965
Duke Energy Carolinas \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	4,123	3,861
Net assets (liabilities)		3,861
Duke Energy Carolinas \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	62	20
Total assets	1,037	1,078
Derivative liabilities		(20)
Net assets (liabilities)		1,058
Duke Energy Carolinas \| Not Categorized
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	47	46
Net assets (liabilities)		46
Duke Energy Carolinas \| NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	63	30
Equity securities, FV-NI	3,738	3,685
Debt securities, available-for-sale	1,344	1,250
Duke Energy Carolinas \| NDTF \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	63	30
Debt securities, available-for-sale	369	192
Duke Energy Carolinas \| NDTF \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	975	1,058
Duke Energy Carolinas \| NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	3,738	3,685
Duke Energy Carolinas \| NDTF equity securities \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	3,691	3,639
Duke Energy Carolinas \| NDTF equity securities \| Not Categorized
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	47	46
Progress Energy
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	1,517
Derivative assets	103	33
Total assets	4,498	4,329
Derivative liabilities	(28)	(29)
Net assets (liabilities)	4,470	4,300
Progress Energy \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	3,528	3,485
Net assets (liabilities)	3,528	3,485
Progress Energy \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	103	33
Total assets	970	844
Derivative liabilities	(28)	(29)
Net assets (liabilities)	942	815
Progress Energy \| NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	130	147
Equity securities, FV-NI	2,641	2,550
Debt securities, available-for-sale	1,491	1,467
Progress Energy \| NDTF \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	130	147
Debt securities, available-for-sale	650	682
Progress Energy \| NDTF \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	841	785
Progress Energy \| NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	2,641	2,550
Progress Energy \| NDTF equity securities \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	2,641	2,550
Progress Energy \| Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	107	106
Debt securities, available-for-sale	26	26
Progress Energy \| Other Investments \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	107	106
Progress Energy \| Other Investments \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	26	26
Duke Energy Progress
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	1,003
Derivative assets	100	33
Total assets	3,746	3,562
Derivative liabilities	(9)	(14)
Net assets (liabilities)	3,737	3,548
Duke Energy Progress \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	2,880	2,773
Net assets (liabilities)	2,880	2,773
Duke Energy Progress \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	100	33
Total assets	866	789
Derivative liabilities	(9)	(14)
Net assets (liabilities)	857	775
Duke Energy Progress \| NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	95	76
Equity securities, FV-NI	2,547	2,459
Debt securities, available-for-sale	1,003	993
Duke Energy Progress \| NDTF \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	95	76
Debt securities, available-for-sale	237	237
Duke Energy Progress \| NDTF \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	766	756
Duke Energy Progress \| NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	2,547	2,459
Duke Energy Progress \| NDTF equity securities \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	2,547	2,459
Duke Energy Progress \| Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	1	1
Duke Energy Progress \| Other Investments \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	1	1
Duke Energy Florida
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	514
Derivative assets	3
Total assets	648	663
Derivative liabilities	(3)
Net assets (liabilities)	645	663
Duke Energy Florida \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	544	608
Net assets (liabilities)	544	608
Duke Energy Florida \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	3
Total assets	104	55
Derivative liabilities	(3)
Net assets (liabilities)	101	55
Duke Energy Florida \| NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	35	71
Equity securities, FV-NI	94	91
Debt securities, available-for-sale	488	474
Duke Energy Florida \| NDTF \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	35	71
Debt securities, available-for-sale	413	445
Duke Energy Florida \| NDTF \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	75	29
Duke Energy Florida \| NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	94	91
Duke Energy Florida \| NDTF equity securities \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	94	91
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	26	26
Duke Energy Florida \| Other Investments \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	2	1
Duke Energy Florida \| Other Investments \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	26	26
Duke Energy Indiana
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	45
Derivative assets	2	6
Total assets	149	149
Derivative liabilities		(1)
Net assets (liabilities)	149	148
Duke Energy Indiana \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	102	98
Derivative liabilities		(1)
Net assets (liabilities)	102	97
Duke Energy Indiana \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	45	45
Net assets (liabilities)	45	45
Duke Energy Indiana \| Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	2	6
Total assets	2	6
Net assets (liabilities)	2	6
Duke Energy Indiana \| Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents		1
Equity securities, FV-NI	102	97
Debt securities, available-for-sale	45	45
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	102	97
Duke Energy Indiana \| Other Investments \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	45	45
Piedmont
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	1	1
Derivative liabilities	(148)	(122)
Net assets (liabilities)	(147)	(121)
Piedmont \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	1	1
Net assets (liabilities)	1	1
Piedmont \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	(148)	(122)
Net assets (liabilities)	$ (148)	$ (122)

Fair Value Measurements (Reconc

Fair Value Measurements (Reconciliation of Assets and Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Derivatives (net)
Balance at beginning of period	$ (77)	$ (102)
Total pretax realized or unrealized losses included in comprehensive income	(44)
Purchases, sales, issuances and settlements:
Settlements	(7)	(9)
Total gains included on the Condensed Consolidated Balance Sheet	2	23
Balance at end of period	(126)	(88)
Duke Energy Indiana
Derivatives (net)
Balance at beginning of period	6	11
Purchases, sales, issuances and settlements:
Settlements	(6)	(6)
Total gains included on the Condensed Consolidated Balance Sheet	2	(3)
Balance at end of period	$ 2	2
Piedmont
Derivatives (net)
Balance at beginning of period		(117)
Purchases, sales, issuances and settlements:
Total gains and settlements		26
Balance at end of period		$ (91)

Fair Value Measurements (Quanti

Fair Value Measurements (Quantitative Level 3 Fair Value Disclosures) (Details) $ in Millions	Mar. 31, 2021USD ($)$ / MWh	Dec. 31, 2020USD ($)$ / MWh	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Fair Value Measurement Inputs and Valuation Techniques
Net derivative asset (liability) \| $	$ (126)	$ (77)	$ (88)	$ (102)
Electricity contracts \| Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques
Net derivative asset (liability) \| $		$ (84)
Electricity contracts \| Discounted cash flow \| Minimum
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu)		14.68
Electricity contracts \| Discounted cash flow \| Maximum
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu)		151.84
Electricity contracts \| Discounted cash flow \| Weighted Average
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu)		28.84
Electricity contracts \| RTO auction pricing
Fair Value Measurement Inputs and Valuation Techniques
Net derivative asset (liability) \| $	$ (128)
Electricity contracts \| RTO auction pricing \| Minimum
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu)	15.55
Electricity contracts \| RTO auction pricing \| Maximum
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu)	134.48
Electricity contracts \| RTO auction pricing \| Weighted Average
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu)	34.80
Duke Energy Indiana
Fair Value Measurement Inputs and Valuation Techniques
Net derivative asset (liability) \| $	$ 2	$ 6	$ 2	$ 11
Duke Energy Indiana \| FTRs \| RTO auction pricing
Fair Value Measurement Inputs and Valuation Techniques
Net derivative asset (liability) \| $	$ 2	$ 6
Duke Energy Indiana \| FTRs \| RTO auction pricing \| Minimum
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu)	(1.02)	(2.40)
Duke Energy Indiana \| FTRs \| RTO auction pricing \| Maximum
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu)	7.23	7.41
Duke Energy Indiana \| FTRs \| RTO auction pricing \| Weighted Average
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu)	0.80	1.05
Duke Energy Ohio \| FTRs \| RTO auction pricing
Fair Value Measurement Inputs and Valuation Techniques
Net derivative asset (liability) \| $		$ 1
Duke Energy Ohio \| FTRs \| RTO auction pricing \| Minimum
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu)		0.25
Duke Energy Ohio \| FTRs \| RTO auction pricing \| Maximum
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu)		1.68
Duke Energy Ohio \| FTRs \| RTO auction pricing \| Weighted Average
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu)		0.79

Fair Value Measurements (Other

Fair Value Measurements (Other Fair Value Disclosure) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	$ 60,354	$ 59,863
Long-term debt, fair value	64,641	69,292
Piedmont Natural Gas and Progress Energy
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unamortized debt discount (premium), net	1,300	1,300
Duke Energy Carolinas
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	12,329	12,218
Long-term debt, fair value	13,461	14,917
Progress Energy
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	19,333	19,264
Long-term debt, fair value	21,838	23,470
Duke Energy Progress
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	9,356	9,258
Long-term debt, fair value	10,131	10,862
Duke Energy Florida
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	7,884	7,915
Long-term debt, fair value	9,018	9,756
Duke Energy Ohio
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	3,090	3,089
Long-term debt, fair value	3,397	3,650
Duke Energy Indiana
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	4,091	4,091
Long-term debt, fair value	4,691	5,204
Piedmont
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	3,127	2,780
Long-term debt, fair value	$ 3,412	$ 3,306

Variable Interest Entities (Nar

Variable Interest Entities (Narrative) (Details) - USD ($)	3 Months Ended	12 Months Ended
Variable Interest Entities (Narrative) (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020	Feb. 28, 2021
ACP \| Current liabilities \| ACP
Variable Interest Entities [Line Items]
Guarantor obligations settled			$ 855,000,000
VIE primary beneficiary
Variable Interest Entities [Line Items]
Variable interest entity, financial or other support, amount	$ 0	$ 0
VIE primary beneficiary \| CRC
Variable Interest Entities [Line Items]
Percent of proceeds received as cash	75.00%
Percent of proceeds received as subordinated note	25.00%
Minimum equity balance required by Cinergy Receivables	$ 3,000,000
VIE not primary beneficiary \| ACP
Variable Interest Entities [Line Items]
Variable interest entity ownership interest	47.00%
VIE not primary beneficiary \| OVEC
Variable Interest Entities [Line Items]
Variable interest entity ownership interest	9.00%

Variable Interest Entities (Sch

Variable Interest Entities (Schedule of Accounts Receivable Securitizations) (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Variable Interest Entities [Line Items]
Long-Term Debt	$ 54,768,000,000	$ 55,625,000,000
Duke Energy Carolinas
Variable Interest Entities [Line Items]
Long-Term Debt	11,522,000,000	11,412,000,000
Duke Energy Progress
Variable Interest Entities [Line Items]
Long-Term Debt	7,904,000,000	8,505,000,000
Duke Energy Florida
Variable Interest Entities [Line Items]
Long-Term Debt	7,060,000,000	7,092,000,000
CRC \| VIE primary beneficiary
Variable Interest Entities [Line Items]
Facility size	350,000,000
Long-Term Debt	350,000,000	350,000,000
Accounts receivable from securitization	472,000,000	547,000,000
DERF \| Duke Energy Carolinas \| VIE primary beneficiary
Variable Interest Entities [Line Items]
Facility size	475,000,000
Long-Term Debt	430,000,000	364,000,000
Accounts receivable from securitization	613,000,000	696,000,000
DEPR \| Duke Energy Progress \| VIE primary beneficiary
Variable Interest Entities [Line Items]
Facility size	350,000,000
Long-Term Debt	350,000,000	250,000,000
Accounts receivable from securitization	422,000,000	500,000,000
DEFR \| Duke Energy Florida \| VIE primary beneficiary
Variable Interest Entities [Line Items]
Facility size	250,000,000
Long-Term Debt	250,000,000	250,000,000
Accounts receivable from securitization	$ 323,000,000	$ 397,000,000

Variable Interest Entities (S_2

Variable Interest Entities (Schedule of Consolidated VIEs) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Variable Interest Entities [Line Items]
Regulatory Assets: Current	$ 1,650	$ 1,641
Current Assets: Other	619	462
Other Noncurrent Assets: Regulatory assets	12,441	12,421
Property, Plant and Equipment: Cost	157,372	155,580
Accumulated depreciation and amortization	(49,772)	(48,827)
Other Noncurrent Assets: Other	3,715	3,601
Current Liabilities: Other	1,858	2,936
Current maturities of long-term debt	5,586	4,238
Long-Term Debt	54,768	55,625
Other Noncurrent Liabilities: AROs	12,299	12,286
Other Noncurrent Liabilities: Other	1,769	1,719
Duke Energy Florida
Variable Interest Entities [Line Items]
Regulatory Assets: Current	352	265
Current Assets: Other	82	41
Other Noncurrent Assets: Regulatory assets	1,717	1,799
Property, Plant and Equipment: Cost	22,459	22,123
Accumulated depreciation and amortization	(5,646)	(5,560)
Other Noncurrent Assets: Other	355	335
Current Liabilities: Other	356	374
Current maturities of long-term debt	824	823
Long-Term Debt	7,060	7,092
Other Noncurrent Liabilities: AROs	493	514
Other Noncurrent Liabilities: Other	267	209
DEFPF \| Duke Energy Florida \| VIE primary beneficiary
Variable Interest Entities [Line Items]
Receivables of VIEs	4	4
Regulatory Assets: Current	54	53
Current Assets: Other	14	39
Other Noncurrent Assets: Regulatory assets	927	937
Current Liabilities: Other	2	10
Current maturities of long-term debt	55	55
Long-Term Debt	972	1,002
Commercial Renewables \| VIE primary beneficiary
Variable Interest Entities [Line Items]
Current Assets: Other	319	257
Property, Plant and Equipment: Cost	6,860	6,394
Accumulated depreciation and amortization	(1,297)	(1,242)
Other Noncurrent Assets: Other	66	67
Current maturities of long-term debt	167	167
Long-Term Debt	1,584	1,569
Other Noncurrent Liabilities: AROs	153	148
Other Noncurrent Liabilities: Other	$ 331	$ 316

Variable Interest Entities (S_3

Variable Interest Entities (Schedule of Non-Consolidated VIEs) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates	$ 919	$ 961
Other noncurrent assets	3,715	3,601
Total Assets	163,465	162,388
Other current liabilities	1,858	2,936
Other Noncurrent Liabilities: Other	1,769	1,719
VIE not primary beneficiary
Variable Interest Entities [Line Items]
Other current assets	4
Investments in equity method unconsolidated affiliates	483	530
Other noncurrent assets		31
Deferred tax asset	29
Total Assets	516	561
Other current liabilities	41	933
Other Noncurrent Liabilities: Other	58	18
Total liabilities	99	951
Net assets	417	(390)
Duke Energy Ohio
Variable Interest Entities [Line Items]
Other noncurrent assets	75	72
Total Assets	10,141	10,025
Other current liabilities	67	70
Other Noncurrent Liabilities: Other	97	99
Duke Energy Ohio \| VIE not primary beneficiary
Variable Interest Entities [Line Items]
Receivables from affiliated companies	46	83
Total Assets	46	83
Net assets	46	83
Duke Energy Indiana
Variable Interest Entities [Line Items]
Other noncurrent assets	251	253
Total Assets	14,063	14,041
Other current liabilities	82	83
Other Noncurrent Liabilities: Other	35	30
Duke Energy Indiana \| VIE not primary beneficiary
Variable Interest Entities [Line Items]
Receivables from affiliated companies	60	110
Total Assets	60	110
Net assets	60	110
Pipeline Investments \| VIE not primary beneficiary
Variable Interest Entities [Line Items]
Other current assets	4
Investments in equity method unconsolidated affiliates	3
Other noncurrent assets		31
Deferred tax asset	29
Total Assets	36	31
Other current liabilities	38	928
Other Noncurrent Liabilities: Other	48	8
Total liabilities	86	936
Net assets	(50)	(905)
Commercial Renewables \| VIE not primary beneficiary
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates	480	530
Total Assets	480	530
Other current liabilities	3	5
Other Noncurrent Liabilities: Other	10	10
Total liabilities	13	15
Net assets	$ 467	$ 515

Variable Interest Entities (Rec

Variable Interest Entities (Receivables Sold) (Details) - VIE not primary beneficiary - CRC - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Duke Energy Ohio
Variable Interest Entities [Line Items]
Receivables sold	$ 241	$ 270
Less: Retained interests	46	83
Net receivables sold	195	187
Duke Energy Indiana
Variable Interest Entities [Line Items]
Receivables sold	285	344
Less: Retained interests	60	110
Net receivables sold	$ 225	$ 234

Variable Interest Entities (Sal

Variable Interest Entities (Sales and Cash Flows) (Details) - VIE not primary beneficiary - CRC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Duke Energy Ohio
Variable Interest Entities [Line Items]
Receivables sold	$ 561	$ 537
Loss recognized on sale	3	4
Cash proceeds from receivables sold	596	559
Return received on retained interests	1	2
Duke Energy Indiana
Variable Interest Entities [Line Items]
Receivables sold	698	647
Loss recognized on sale	3	4
Cash proceeds from receivables sold	746	672
Return received on retained interests	$ 2	$ 2

Revenue (Remaining Performance

Revenue (Remaining Performance Obligations) (Details) $ in Millions	Mar. 31, 2021USD ($)
Progress Energy
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 325
Progress Energy \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	9 months
Revenue, remaining performance obligation, amount	$ 71
Progress Energy \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, remaining performance obligation, amount	$ 107
Progress Energy \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, remaining performance obligation, amount	$ 44
Progress Energy \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, remaining performance obligation, amount	$ 45
Progress Energy \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, remaining performance obligation, amount	$ 7
Progress Energy \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period
Revenue, remaining performance obligation, amount	$ 51
Duke Energy Progress
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 30
Duke Energy Progress \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	9 months
Revenue, remaining performance obligation, amount	$ 6
Duke Energy Progress \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, remaining performance obligation, amount	$ 8
Duke Energy Progress \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, remaining performance obligation, amount	$ 8
Duke Energy Progress \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, remaining performance obligation, amount	$ 8
Duke Energy Progress \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Duke Energy Progress \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period
Duke Energy Florida
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 295
Duke Energy Florida \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	9 months
Revenue, remaining performance obligation, amount	$ 65
Duke Energy Florida \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, remaining performance obligation, amount	$ 99
Duke Energy Florida \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, remaining performance obligation, amount	$ 36
Duke Energy Florida \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, remaining performance obligation, amount	$ 37
Duke Energy Florida \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, remaining performance obligation, amount	$ 7
Duke Energy Florida \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period
Revenue, remaining performance obligation, amount	$ 51
Duke Energy Indiana
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 57
Duke Energy Indiana \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	9 months
Revenue, remaining performance obligation, amount	$ 2
Duke Energy Indiana \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Duke Energy Indiana \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, remaining performance obligation, amount	$ 7
Duke Energy Indiana \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, remaining performance obligation, amount	$ 12
Duke Energy Indiana \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, remaining performance obligation, amount	$ 12
Duke Energy Indiana \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period
Revenue, remaining performance obligation, amount	$ 24
Piedmont
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 637
Piedmont \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	9 months
Revenue, remaining performance obligation, amount	$ 50
Piedmont \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, remaining performance obligation, amount	$ 67
Piedmont \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, remaining performance obligation, amount	$ 64
Piedmont \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, remaining performance obligation, amount	$ 61
Piedmont \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, remaining performance obligation, amount	$ 60
Piedmont \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period
Revenue, remaining performance obligation, amount	$ 335

Revenue (Remaining Performanc_2

Revenue (Remaining Performance Obligations Total) (Details) $ in Millions	Mar. 31, 2021USD ($)
Progress Energy
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 325
Duke Energy Progress
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	30
Duke Energy Florida
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	295
Duke Energy Indiana
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	57
Piedmont
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 637

Revenue (Disaggregation of Reve

Revenue (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 6,094	$ 5,800
Revenue from sources other than contracts with customers	56	149
Total operating revenues	6,150	5,949
Electric Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	5,273	5,134
Total operating revenues	5,273	5,174
Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,462	2,261
Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| General
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,419	1,492
Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	662	693
Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	504	497
Electric Utilities and Infrastructure \| Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	226	191
Gas Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	761	602
Total operating revenues	752	640
Gas Utilities and Infrastructure \| Gas Utilities and Infrastructure \| Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	460	362
Gas Utilities and Infrastructure \| Gas Utilities and Infrastructure \| Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	204	169
Gas Utilities and Infrastructure \| Gas Utilities and Infrastructure \| Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	50	41
Gas Utilities and Infrastructure \| Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	47	30
Commercial Renewables
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	54	58
Total operating revenues	119	129
Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6	6
Total operating revenues	6	6
Duke Energy Carolinas
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,739	1,748
Revenue from sources other than contracts with customers	(23)
Total operating revenues	1,716	1,748
Duke Energy Carolinas \| Electric Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,739	1,748
Duke Energy Carolinas \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	793	756
Duke Energy Carolinas \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| General
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	502	549
Duke Energy Carolinas \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	256	269
Duke Energy Carolinas \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	114	114
Duke Energy Carolinas \| Electric Utilities and Infrastructure \| Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	74	60
Progress Energy
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,479	2,367
Revenue from sources other than contracts with customers	26	55
Total operating revenues	2,505	2,422
Progress Energy \| Electric Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,479	2,367
Progress Energy \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,162	1,064
Progress Energy \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| General
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	624	648
Progress Energy \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	207	216
Progress Energy \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	326	321
Progress Energy \| Electric Utilities and Infrastructure \| Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	160	118
Duke Energy Progress
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,386	1,317
Revenue from sources other than contracts with customers	15	21
Total operating revenues	1,401	1,338
Duke Energy Progress \| Electric Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,386	1,317
Duke Energy Progress \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	560	502
Duke Energy Progress \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| General
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	306	319
Duke Energy Progress \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	145	154
Duke Energy Progress \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	292	279
Duke Energy Progress \| Electric Utilities and Infrastructure \| Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	83	63
Duke Energy Florida
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,093	1,050
Revenue from sources other than contracts with customers	8	30
Total operating revenues	1,101	1,080
Duke Energy Florida \| Electric Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,093	1,050
Duke Energy Florida \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	602	562
Duke Energy Florida \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| General
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	318	329
Duke Energy Florida \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	62	62
Duke Energy Florida \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	34	42
Duke Energy Florida \| Electric Utilities and Infrastructure \| Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	77	55
Duke Energy Ohio
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	535	504
Revenue from sources other than contracts with customers	(3)	(6)
Total operating revenues	532	498
Duke Energy Ohio \| Electric Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	365	352
Duke Energy Ohio \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	195	176
Duke Energy Ohio \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| General
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	104	114
Duke Energy Ohio \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	31	35
Duke Energy Ohio \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	13	7
Duke Energy Ohio \| Electric Utilities and Infrastructure \| Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	22	20
Duke Energy Ohio \| Gas Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	170	152
Duke Energy Ohio \| Gas Utilities and Infrastructure \| Gas Utilities and Infrastructure \| Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	110	97
Duke Energy Ohio \| Gas Utilities and Infrastructure \| Gas Utilities and Infrastructure \| Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	48	43
Duke Energy Ohio \| Gas Utilities and Infrastructure \| Gas Utilities and Infrastructure \| Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	7	6
Duke Energy Ohio \| Gas Utilities and Infrastructure \| Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	5	6
Duke Energy Indiana
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	737	692
Revenue from sources other than contracts with customers	8
Total operating revenues	745	692
Duke Energy Indiana \| Electric Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	737	692
Duke Energy Indiana \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	313	265
Duke Energy Indiana \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| General
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	189	181
Duke Energy Indiana \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	167	175
Duke Energy Indiana \| Electric Utilities and Infrastructure \| Electric Utilities and Infrastructure \| Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	50	55
Duke Energy Indiana \| Electric Utilities and Infrastructure \| Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	18	16
Piedmont
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	598	461
Revenue from sources other than contracts with customers	8	51
Total operating revenues	606	512
Piedmont \| Gas Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	598	461
Piedmont \| Gas Utilities and Infrastructure \| Gas Utilities and Infrastructure \| Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	351	264
Piedmont \| Gas Utilities and Infrastructure \| Gas Utilities and Infrastructure \| Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	156	126
Piedmont \| Gas Utilities and Infrastructure \| Gas Utilities and Infrastructure \| Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	43	36
Piedmont \| Gas Utilities and Infrastructure \| Gas Utilities and Infrastructure \| Power Generation
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	22	11
Piedmont \| Gas Utilities and Infrastructure \| Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 26	$ 24

Revenue (Reserve for Credit Los

Revenue (Reserve for Credit Losses for Trade and Other Receivables) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 146	$ 76
Cumulative Change in Accounting Principle	147	89
Write-Offs	(21)	(10)
Credit Loss Expense	17	18
Other Adjustments	5
Ending balance	147	89
Duke Energy Carolinas
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	23	10
Cumulative Change in Accounting Principle	34	11
Write-Offs	(8)	(3)
Credit Loss Expense	10	3
Other Adjustments	9
Ending balance	34	11
Progress Energy
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	37	16
Cumulative Change in Accounting Principle	37	20
Write-Offs	(10)	(4)
Credit Loss Expense	7	6
Other Adjustments	3
Ending balance	37	20
Duke Energy Progress
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	23	8
Cumulative Change in Accounting Principle	23	9
Write-Offs	(5)	(2)
Credit Loss Expense	2	2
Other Adjustments	3
Ending balance	23	9
Duke Energy Florida
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	14	7
Cumulative Change in Accounting Principle	15	11
Write-Offs	(5)	(2)
Credit Loss Expense	5	5
Other Adjustments	1
Ending balance	15	11
Duke Energy Ohio
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	4	4
Cumulative Change in Accounting Principle	4	5
Credit Loss Expense		1
Ending balance	4	5
Duke Energy Indiana
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	3	3
Cumulative Change in Accounting Principle	3	3
Ending balance	3	3
Piedmont
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	12	6
Cumulative Change in Accounting Principle	14	9
Write-Offs	(1)	(1)
Credit Loss Expense	3	3
Ending balance	$ 14	9
Cumulative Change in Accounting Principle
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		5
Cumulative Change in Accounting Principle		5
Cumulative Change in Accounting Principle \| Duke Energy Carolinas
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		1
Cumulative Change in Accounting Principle		1
Cumulative Change in Accounting Principle \| Progress Energy
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		2
Cumulative Change in Accounting Principle		2
Cumulative Change in Accounting Principle \| Duke Energy Progress
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		1
Cumulative Change in Accounting Principle		1
Cumulative Change in Accounting Principle \| Duke Energy Florida
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		1
Cumulative Change in Accounting Principle		1
Cumulative Change in Accounting Principle \| Piedmont
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		1
Cumulative Change in Accounting Principle		$ 1

Revenue (Aging of Trade Receiva

Revenue (Aging of Trade Receivables) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable, Past Due [Line Items]
Unbilled Receivables	$ 758	$ 969
Trade and Other Receivables, not past due	1,656	1,789
Deferred Payment Arrangements	170	215
Trade and Other Receivables	2,931	3,299
30-60 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	181	185
60-90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	46	22
90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	120	119
Duke Energy Carolinas
Financing Receivable, Past Due [Line Items]
Unbilled Receivables	293	328
Trade and Other Receivables, not past due	337	445
Deferred Payment Arrangements	80	96
Trade and Other Receivables	818	966
Duke Energy Carolinas \| 30-60 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	62	80
Duke Energy Carolinas \| 60-90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	15	1
Duke Energy Carolinas \| 90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	31	16
Progress Energy
Financing Receivable, Past Due [Line Items]
Unbilled Receivables	183	283
Trade and Other Receivables, not past due	633	707
Deferred Payment Arrangements	53	80
Trade and Other Receivables	952	1,166
Progress Energy \| 30-60 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	46	54
Progress Energy \| 60-90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	11	10
Progress Energy \| 90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	26	32
Duke Energy Progress
Financing Receivable, Past Due [Line Items]
Unbilled Receivables	90	167
Trade and Other Receivables, not past due	357	398
Deferred Payment Arrangements	37	52
Trade and Other Receivables	525	655
Duke Energy Progress \| 30-60 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	31	25
Duke Energy Progress \| 60-90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	6	4
Duke Energy Progress \| 90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	4	9
Duke Energy Florida
Financing Receivable, Past Due [Line Items]
Unbilled Receivables	93	116
Trade and Other Receivables, not past due	275	307
Deferred Payment Arrangements	16	28
Trade and Other Receivables	426	509
Duke Energy Florida \| 30-60 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	15	29
Duke Energy Florida \| 60-90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	5	6
Duke Energy Florida \| 90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	22	23
Duke Energy Ohio
Financing Receivable, Past Due [Line Items]
Unbilled Receivables	4	2
Trade and Other Receivables, not past due	55	60
Deferred Payment Arrangements	4
Trade and Other Receivables	102	102
Duke Energy Ohio \| CRC
Financing Receivable, Past Due [Line Items]
Unbilled Receivables	55	87
Duke Energy Ohio \| 30-60 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	8	8
Duke Energy Ohio \| 60-90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	3	2
Duke Energy Ohio \| 90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	28	30
Duke Energy Indiana
Financing Receivable, Past Due [Line Items]
Unbilled Receivables	16	16
Trade and Other Receivables, not past due	35	26
Trade and Other Receivables	66	58
Duke Energy Indiana \| CRC
Financing Receivable, Past Due [Line Items]
Unbilled Receivables	87	134
Duke Energy Indiana \| 30-60 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	3	3
Duke Energy Indiana \| 60-90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	1	1
Duke Energy Indiana \| 90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	11	12
Piedmont
Financing Receivable, Past Due [Line Items]
Unbilled Receivables	44	86
Trade and Other Receivables, not past due	185	149
Deferred Payment Arrangements	8	7
Trade and Other Receivables	271	262
Piedmont \| 30-60 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	21	8
Piedmont \| 60-90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	6	3
Piedmont \| 90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	$ 7	$ 9

Stockholders' Equity (Earnings

Stockholders' Equity (Earnings Per Share Data) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Class of Stock [Line Items]
Net income available to Duke Energy common stockholders	$ 953	$ 899
Accumulated preferred stock dividends adjustment	12	13
Less: Impact of participating securities	1	1
Income from continuing operations available to Duke Energy common stockholders	$ 964	$ 911
Weighted average common shares outstanding – basic (in shares)	769	734
Equity forwards (in shares)	0	2
Weighted average common shares outstanding – diluted (in shares)	769	736
EPS available to Duke Energy common stockholders
Basic (in usd per share)	$ 1.25	$ 1.24
Diluted (in usd per share)	$ 1.25	$ 1.24
Potentially dilutive items excluded from the calculation (in shares)	2	2
Common Stock
EPS available to Duke Energy common stockholders
Dividends declared per common share (in usd per share)	$ 0.965	$ 0.945
Preferred stock, Series A
EPS available to Duke Energy common stockholders
Dividends declared on preferred stock per depositary share (in usd per share)	$ 0.359	0.359
Cumulative dividend rate per annum	5.75%
Liquidation preference per share (in usd per share)	$ 25
Preferred stock, Series B
EPS available to Duke Energy common stockholders
Dividends declared on preferred stock per depositary share (in usd per share)	$ 24.375	$ 24.917
Cumulative dividend rate per annum	4.875%
Liquidation preference per share (in usd per share)	$ 1,000

Employee Benefit Plans (Compone

Employee Benefit Plans (Components of Net Periodic Pension Costs) (Details) - Qualified Pension Plans - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 44	$ 41
Interest cost on projected benefit obligation	55	67
Expected return on plan assets	(139)	(143)
Amortization of actuarial loss	33	34
Amortization of prior service credit	(7)	(8)
Amortization of settlement charges	2	2
Net periodic pension costs	(12)	(7)
Duke Energy Carolinas
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	14	12
Interest cost on projected benefit obligation	13	16
Expected return on plan assets	(35)	(36)
Amortization of actuarial loss	7	7
Amortization of prior service credit	(2)	(2)
Amortization of settlement charges	1	1
Net periodic pension costs	(2)	(2)
Progress Energy
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	13	12
Interest cost on projected benefit obligation	17	21
Expected return on plan assets	(47)	(48)
Amortization of actuarial loss	10	11
Amortization of prior service credit	(1)	(1)
Amortization of settlement charges	1	1
Net periodic pension costs	(7)	(4)
Duke Energy Progress
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	7	6
Interest cost on projected benefit obligation	7	10
Expected return on plan assets	(21)	(22)
Amortization of actuarial loss	5	5
Net periodic pension costs	(2)	(1)
Duke Energy Florida
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	5	5
Interest cost on projected benefit obligation	10	12
Expected return on plan assets	(26)	(25)
Amortization of actuarial loss	5	6
Net periodic pension costs	(6)	(2)
Duke Energy Ohio
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	1	1
Interest cost on projected benefit obligation	3	4
Expected return on plan assets	(7)	(7)
Amortization of actuarial loss	2	2
Net periodic pension costs	(1)
Duke Energy Indiana
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	2	2
Interest cost on projected benefit obligation	5	6
Expected return on plan assets	(10)	(11)
Amortization of actuarial loss	3	3
Piedmont
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	1	1
Interest cost on projected benefit obligation	2	2
Expected return on plan assets	(5)	(5)
Amortization of actuarial loss	2	2
Amortization of prior service credit	(1)	(2)
Net periodic pension costs	$ (1)	$ (2)

Income Taxes (Effective Tax Rat

Income Taxes (Effective Tax Rates) (Details)	3 Months Ended
Income Taxes (Effective Tax Rates) (Details)	Mar. 31, 2021	Mar. 31, 2020
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	8.20%	13.30%
Duke Energy Carolinas
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	6.90%	16.10%
Progress Energy
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	12.90%	17.50%
Duke Energy Progress
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	8.30%	17.10%
Duke Energy Florida
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	19.30%	20.00%
Duke Energy Ohio
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	13.30%	17.70%
Duke Energy Indiana
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	17.60%	20.80%
Piedmont
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	11.40%	10.10%