Progress Energy (PREX) 10-Q 12 May 20 2020 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2020	Apr. 30, 2020
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2020
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		734,852,539
Document Fiscal Year Focus	2020
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 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 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 Shell Company	false
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0000081020
Piedmont Natural Gas
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 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 [Member]
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 [Member]
Document Information [Line Items]
Title of 12(b) Security	5.625% Junior Subordinated Debentures
Trading Symbol	DUKB
Security Exchange Name	NYSE
Depositary Share [Member]
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, 2020		Mar. 31, 2019
Operating Revenues
Regulated electric	$ 5,124		$ 5,285
Regulated natural gas	638		728
Nonregulated electric and other	187		150
Total operating revenues	5,949		6,163
Operating Expenses
Operation, maintenance and other	1,339		1,419
Depreciation and amortization	1,130		1,089
Property and other taxes	345		343
Impairment charges	2
Total operating expenses	4,462		4,787
Gains (Losses) on Sales of Other Assets and Other, net	1		(3)
Operating Income	1,488		1,373
Other Income and Expenses
Equity in earnings of unconsolidated affiliates	44		43
Other income and expenses, net	46		115
Total other income and expenses	90		158
Interest Expense	551		543
Income Before Income Taxes	1,027		988
Income Tax Expense	137		95
Net Income	890		893
Less: Net Loss Attributable to Noncontrolling Interests	(48)		(7)
Net Income Attributable to Parent	938		900
Less: Preferred Dividends	39
Net Income (Loss) Available to Common Stockholders, Basic	899		900
Other Comprehensive Income (Loss), net of tax
Pension and OPEB adjustments	1
Net unrealized (losses) gains on cash flow hedges	(81)		(17)
Unrealized gains on available-for-sale securities	1		4
Other Comprehensive Loss, net of tax	(77)	[1]	(12)
Comprehensive Income	813		881
Less: Comprehensive Loss Attributable to Noncontrolling Interests	(62)		(7)
Comprehensive Income Available to Duke Energy Corporation Common Stockholders	$ 836		$ 888
Net income attributable to Duke Energy Corporation common stockholders
Basic and Diluted (in usd per share)	$ 1.24		$ 1.24
Weighted average shares outstanding
Weighted Average Number of Shares Outstanding, Basic	734		727
Weighted Average Number of Shares Outstanding, Diluted	736		727
Duke Energy Carolinas
Operating Revenues
Total operating revenues	$ 1,748		$ 1,744
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	453		472
Operation, maintenance and other	386		440
Depreciation and amortization	343		317
Property and other taxes	81		80
Impairment charges	2
Total operating expenses	1,265		1,309
Gains (Losses) on Sales of Other Assets and Other, net	1
Operating Income	484		435
Other Income and Expenses
Total other income and expenses	43		31
Interest Expense	123		110
Income Before Income Taxes	404		356
Income Tax Expense	65		63
Net Income Attributable to Parent	339		293
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Available to Duke Energy Corporation Common Stockholders	339		293
Progress Energy
Operating Revenues
Total operating revenues	2,422		2,572
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	763		925
Operation, maintenance and other	554		567
Depreciation and amortization	452		455
Property and other taxes	135		137
Total operating expenses	1,904		2,084
Gains (Losses) on Sales of Other Assets and Other, net	(1)
Operating Income	517		488
Other Income and Expenses
Total other income and expenses	32		31
Interest Expense	206		219
Income Before Income Taxes	343		300
Income Tax Expense	60		52
Net Income	283		248
Less: Net Loss Attributable to Noncontrolling Interests			(1)
Net Income Attributable to Parent	283		249
Other Comprehensive Income (Loss), net of tax
Pension and OPEB adjustments			1
Net unrealized (losses) gains on cash flow hedges	1		2
Unrealized gains on available-for-sale securities	1
Other Comprehensive Loss, net of tax	2		3
Comprehensive Income	285		251
Less: Comprehensive Loss Attributable to Noncontrolling Interests			(1)
Comprehensive Income Available to Duke Energy Corporation Common Stockholders	285		252
Duke Energy Progress
Operating Revenues
Total operating revenues	1,338		1,484
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	405		515
Operation, maintenance and other	305		335
Depreciation and amortization	287		290
Property and other taxes	47		44
Total operating expenses	1,044		1,184
Gains (Losses) on Sales of Other Assets and Other, net	(1)
Operating Income	293		300
Other Income and Expenses
Total other income and expenses	22		24
Interest Expense	69		77
Income Before Income Taxes	246		247
Income Tax Expense	42		44
Net Income Attributable to Parent	204		203
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Available to Duke Energy Corporation Common Stockholders	204		203
Duke Energy Florida
Operating Revenues
Total operating revenues	1,080		1,086
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	358		410
Operation, maintenance and other	245		230
Depreciation and amortization	165		165
Property and other taxes	88		93
Total operating expenses	856		898
Operating Income	224		188
Other Income and Expenses
Total other income and expenses	10		13
Interest Expense	84		82
Income Before Income Taxes	150		119
Income Tax Expense	30		23
Net Income Attributable to Parent	120		96
Other Comprehensive Income (Loss), net of tax
Unrealized gains on available-for-sale securities	1		1
Other Comprehensive Loss, net of tax	1		1
Comprehensive Income Available to Duke Energy Corporation Common Stockholders	121		97
Duke Energy Ohio
Operating Revenues
Regulated electric	346		355
Regulated natural gas	152		176
Total operating revenues	498		531
Operating Expenses
Operation, maintenance and other	123		132
Depreciation and amortization	68		64
Property and other taxes	83		84
Total operating expenses	398		427
Operating Income	100		104
Other Income and Expenses
Total other income and expenses	3		9
Interest Expense	24		30
Income Before Income Taxes	79		83
Income Tax Expense	14		14
Net Income Attributable to Parent	65		69
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Available to Duke Energy Corporation Common Stockholders	65		69
Duke Energy Indiana
Operating Revenues
Total operating revenues	692		768
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	194		257
Operation, maintenance and other	186		189
Depreciation and amortization	132		131
Property and other taxes	22		19
Total operating expenses	534		596
Gains (Losses) on Sales of Other Assets and Other, net			(3)
Operating Income	158		169
Other Income and Expenses
Total other income and expenses	10		19
Interest Expense	43		43
Income Before Income Taxes	125		145
Income Tax Expense	26		35
Net Income Attributable to Parent	99		110
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Available to Duke Energy Corporation Common Stockholders	99		110
Piedmont Natural Gas
Operating Revenues
Total operating revenues	512		579
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	162		273
Operation, maintenance and other	80		80
Depreciation and amortization	45		42
Property and other taxes	12		12
Total operating expenses	299		407
Operating Income	213		172
Other Income and Expenses
Equity in earnings of unconsolidated affiliates	2		2
Other income and expenses, net	12		6
Interest Expense	27		22
Income Before Income Taxes	198		156
Income Tax Expense	20		34
Net Income Attributable to Parent	178		122
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Available to Duke Energy Corporation Common Stockholders	178		122
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	87		93
Fuel used in electric generation and purchased power
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	1,447		1,609
Cost of natural gas
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	199		327
Cost of natural gas | Duke Energy Ohio
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	$ 37		$ 54
[1]	Net of income tax impact of approximately $23 million in the first quarter of 2020 and immaterial income tax impact in the first quarter of 2019.

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020		Mar. 31, 2019
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Net Income	$ 890		$ 893
Other Comprehensive Loss, net of tax(a)
Pension and OPEB adjustments	1
Net unrealized losses on cash flow hedges	(81)		(17)
Reclassification into earnings from cash flow hedges	2		1
Unrealized gains on available-for-sale securities	1		4
Other Comprehensive Loss, net of tax	(77)	[1]	(12)
Comprehensive Income	813		881
Less: Comprehensive Loss Attributable to Noncontrolling Interests	(62)		(7)
Comprehensive Income Attributable to Duke Energy	875		888
Less: Preferred Dividends	39
Comprehensive Income Available to Duke Energy Corporation Common Stockholders	$ 836		$ 888
[1]	Net of income tax impact of approximately $23 million in the first quarter of 2020 and immaterial income tax impact in the first quarter of 2019.

Condensed Consolidated Statem_3

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

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 1,450	$ 311
Receivables (net of allowance for doubtful accounts)	809	1,066
Receivables of VIEs (net of allowance for doubtful accounts)	1,828	1,994
Inventory	3,324	3,232
Regulatory assets (includes amounts related to VIEs)	1,770	1,796
Other (includes amounts related to VIEs)	1,000	764
Total current assets	10,181	9,163
Property, Plant and Equipment
Cost	149,676	147,654
Accumulated depreciation and amortization	(46,599)	(45,773)
Generation facilities to be retired, net	31	246
Net property, plant and equipment	103,108	102,127
Other Noncurrent Assets
Goodwill	19,303	19,303
Regulatory assets (includes amounts related to VIEs)	13,413	13,222
Nuclear decommissioning trust funds	7,052	8,140
Operating lease right-of-use assets, net	1,633	1,658
Investments in equity method unconsolidated affiliates	2,067	1,936
Other (includes amounts related to VIEs)	3,315	3,289
Total other noncurrent assets	46,783	47,548
Total Assets	160,072	158,838
Current Liabilities
Accounts payable	2,364	3,487
Notes payable and commercial paper	3,033	3,135
Taxes accrued	493	392
Interest accrued	571	565
Current maturities of long-term debt (includes amounts related to VIEs)	5,077	3,141
Asset retirement obligations	802	881
Regulatory liabilities	826	784
Other	2,004	2,367
Total current liabilities	15,170	14,752
Long-Term Debt (includes amounts related to VIEs)	56,311	54,985
Other Noncurrent Liabilities
Deferred income taxes	9,321	8,878
Asset retirement obligations	12,497	12,437
Regulatory liabilities	14,029	15,264
Operating lease liabilities	1,414	1,432
Accrued pension and other post-retirement benefit costs	919	934
Investment tax credits	659	624
Other (includes amounts related to VIEs)	1,669	1,581
Total other noncurrent liabilities	40,508	41,150
Commitments and Contingencies
Equity
Common stock	1	1
Additional paid-in capital	40,930	40,881
Retained earnings	4,221	4,108
Accumulated other comprehensive loss	(193)	(130)
Total Duke Energy Corporation stockholders' equity	46,921	46,822
Noncontrolling interests	1,162	1,129
Total equity	48,083	47,951
Total Liabilities and Equity	160,072	158,838
Duke Energy Carolinas
Current Assets
Cash and cash equivalents	16	18
Receivables (net of allowance for doubtful accounts)	212	324
Receivables of VIEs (net of allowance for doubtful accounts)	616	642
Receivables from affiliated companies	87	114
Notes receivable from affiliated companies	436
Inventory	1,067	996
Regulatory assets (includes amounts related to VIEs)	524	550
Other (includes amounts related to VIEs)	31	21
Total current assets	2,989	2,665
Property, Plant and Equipment
Cost	49,534	48,922
Accumulated depreciation and amortization	(16,884)	(16,525)
Net property, plant and equipment	32,650	32,397
Other Noncurrent Assets
Regulatory assets (includes amounts related to VIEs)	3,427	3,360
Nuclear decommissioning trust funds	3,717	4,359
Operating lease right-of-use assets, net	132	123
Other (includes amounts related to VIEs)	1,136	1,149
Total other noncurrent assets	8,412	8,991
Total Assets	44,051	44,053
Current Liabilities
Accounts payable	605	954
Accounts payable to affiliated companies	225	210
Notes payable to affiliated companies		29
Taxes accrued	132	46
Interest accrued	144	115
Current maturities of long-term debt (includes amounts related to VIEs)	457	458
Asset retirement obligations	197	206
Regulatory liabilities	275	255
Other	479	611
Total current liabilities	2,514	2,884
Long-Term Debt (includes amounts related to VIEs)	12,050	11,142
Long-Term Debt Payable to Affiliated Companies	300	300
Other Noncurrent Liabilities
Deferred income taxes	3,968	3,921
Asset retirement obligations	5,552	5,528
Regulatory liabilities	5,766	6,423
Operating lease liabilities	112	102
Accrued pension and other post-retirement benefit costs	82	84
Investment tax credits	230	231
Other (includes amounts related to VIEs)	640	627
Total other noncurrent liabilities	16,350	16,916
Equity
Member's equity	12,844	12,818
Accumulated other comprehensive loss	(7)	(7)
Total member's equity	12,837	12,811
Total Liabilities and Equity	44,051	44,053
Progress Energy
Current Assets
Cash and cash equivalents	52	48
Receivables (net of allowance for doubtful accounts)	159	220
Receivables of VIEs (net of allowance for doubtful accounts)	745	830
Receivables from affiliated companies	49	76
Notes receivable from affiliated companies		164
Inventory	1,463	1,423
Regulatory assets (includes amounts related to VIEs)	954	946
Other (includes amounts related to VIEs)	196	210
Total current assets	3,618	3,917
Property, Plant and Equipment
Cost	55,788	55,070
Accumulated depreciation and amortization	(17,461)	(17,159)
Generation facilities to be retired, net	31	246
Net property, plant and equipment	38,358	38,157
Other Noncurrent Assets
Goodwill	3,655	3,655
Regulatory assets (includes amounts related to VIEs)	6,489	6,346
Nuclear decommissioning trust funds	3,335	3,782
Operating lease right-of-use assets, net	762	788
Other (includes amounts related to VIEs)	1,121	1,049
Total other noncurrent assets	15,362	15,620
Total Assets	57,338	57,694
Current Liabilities
Accounts payable	730	1,104
Accounts payable to affiliated companies	329	310
Notes payable to affiliated companies	2,300	1,821
Taxes accrued	117	46
Interest accrued	214	228
Current maturities of long-term debt (includes amounts related to VIEs)	1,828	1,577
Asset retirement obligations	421	485
Regulatory liabilities	347	330
Other	821	902
Total current liabilities	7,107	6,803
Long-Term Debt (includes amounts related to VIEs)	17,377	17,907
Long-Term Debt Payable to Affiliated Companies	150	150
Other Noncurrent Liabilities
Deferred income taxes	4,537	4,462
Asset retirement obligations	6,020	5,986
Regulatory liabilities	4,708	5,225
Operating lease liabilities	678	697
Accrued pension and other post-retirement benefit costs	480	488
Other (includes amounts related to VIEs)	404	383
Total other noncurrent liabilities	16,827	17,241
Equity
Additional paid-in capital	9,143	9,143
Retained earnings	6,747	6,465
Accumulated other comprehensive loss	(16)	(18)
Total Duke Energy Corporation stockholders' equity	15,874	15,590
Noncontrolling interests	3	3
Total equity	15,877	15,593
Total Liabilities and Equity	57,338	57,694
Duke Energy Progress
Current Assets
Cash and cash equivalents	32	22
Receivables (net of allowance for doubtful accounts)	77	123
Receivables of VIEs (net of allowance for doubtful accounts)	410	489
Receivables from affiliated companies	50	52
Inventory	956	934
Regulatory assets (includes amounts related to VIEs)	503	526
Other (includes amounts related to VIEs)	48	60
Total current assets	2,076	2,206
Property, Plant and Equipment
Cost	34,898	34,603
Accumulated depreciation and amortization	(12,114)	(11,915)
Generation facilities to be retired, net	31	246
Net property, plant and equipment	22,815	22,934
Other Noncurrent Assets
Regulatory assets (includes amounts related to VIEs)	4,392	4,152
Nuclear decommissioning trust funds	2,644	3,047
Operating lease right-of-use assets, net	377	387
Other (includes amounts related to VIEs)	682	651
Total other noncurrent assets	8,095	8,237
Total Assets	32,986	33,377
Current Liabilities
Accounts payable	319	629
Accounts payable to affiliated companies	208	203
Notes payable to affiliated companies	229	66
Taxes accrued	43	17
Interest accrued	90	110
Current maturities of long-term debt (includes amounts related to VIEs)	1,006	1,006
Asset retirement obligations	421	485
Regulatory liabilities	263	236
Other	429	478
Total current liabilities	3,008	3,230
Long-Term Debt (includes amounts related to VIEs)	7,903	7,902
Long-Term Debt Payable to Affiliated Companies	150	150
Other Noncurrent Liabilities
Deferred income taxes	2,446	2,388
Asset retirement obligations	5,442	5,408
Regulatory liabilities	3,790	4,232
Operating lease liabilities	344	354
Accrued pension and other post-retirement benefit costs	235	238
Investment tax credits	135	137
Other (includes amounts related to VIEs)	83	92
Total other noncurrent liabilities	12,475	12,849
Equity
Total member's equity	9,450	9,246
Total Liabilities and Equity	32,986	33,377
Duke Energy Florida
Current Assets
Cash and cash equivalents	12	17
Receivables (net of allowance for doubtful accounts)	80	96
Receivables of VIEs (net of allowance for doubtful accounts)	335	341
Notes receivable from affiliated companies		173
Inventory	508	489
Regulatory assets (includes amounts related to VIEs)	451	419
Other (includes amounts related to VIEs)	37	58
Total current assets	1,423	1,593
Property, Plant and Equipment
Cost	20,880	20,457
Accumulated depreciation and amortization	(5,339)	(5,236)
Net property, plant and equipment	15,541	15,221
Other Noncurrent Assets
Regulatory assets (includes amounts related to VIEs)	2,097	2,194
Nuclear decommissioning trust funds	691	734
Operating lease right-of-use assets, net	386	401
Other (includes amounts related to VIEs)	329	311
Total other noncurrent assets	3,503	3,640
Total Assets	20,467	20,454
Current Liabilities
Accounts payable	411	474
Accounts payable to affiliated companies	111	131
Notes payable to affiliated companies	305
Taxes accrued	74	43
Interest accrued	79	75
Current maturities of long-term debt (includes amounts related to VIEs)	322	571
Regulatory liabilities	84	94
Other	383	415
Total current liabilities	1,769	1,803
Long-Term Debt (includes amounts related to VIEs)	7,384	7,416
Other Noncurrent Liabilities
Deferred income taxes	2,192	2,179
Asset retirement obligations	578	578
Regulatory liabilities	918	993
Operating lease liabilities	334	343
Accrued pension and other post-retirement benefit costs	214	218
Other (includes amounts related to VIEs)	169	136
Total other noncurrent liabilities	4,405	4,447
Equity
Member's equity	6,909	6,789
Accumulated other comprehensive loss		(1)
Total member's equity	6,909	6,788
Total Liabilities and Equity	20,467	20,454
Duke Energy Ohio
Current Assets
Cash and cash equivalents	14	17
Receivables (net of allowance for doubtful accounts)	84	84
Receivables from affiliated companies	52	92
Inventory	121	135
Regulatory assets (includes amounts related to VIEs)	33	49
Other (includes amounts related to VIEs)	11	21
Total current assets	315	398
Property, Plant and Equipment
Cost	10,401	10,241
Accumulated depreciation and amortization	(2,883)	(2,843)
Net property, plant and equipment	7,518	7,398
Other Noncurrent Assets
Goodwill	920	920
Regulatory assets (includes amounts related to VIEs)	567	549
Operating lease right-of-use assets, net	21	21
Other (includes amounts related to VIEs)	56	52
Total other noncurrent assets	1,564	1,542
Total Assets	9,397	9,338
Current Liabilities
Accounts payable	227	288
Accounts payable to affiliated companies	68	68
Notes payable to affiliated companies	399	312
Taxes accrued	170	219
Interest accrued	30	30
Asset retirement obligations	3	1
Regulatory liabilities	66	64
Other	68	75
Total current liabilities	1,031	1,057
Long-Term Debt (includes amounts related to VIEs)	2,595	2,594
Long-Term Debt Payable to Affiliated Companies	25	25
Other Noncurrent Liabilities
Deferred income taxes	942	922
Asset retirement obligations	78	79
Regulatory liabilities	760	763
Operating lease liabilities	20	21
Accrued pension and other post-retirement benefit costs	101	100
Other (includes amounts related to VIEs)	97	94
Total other noncurrent liabilities	1,998	1,979
Equity
Common stock	762	762
Additional paid-in capital	2,776	2,776
Retained earnings	210	145
Total Duke Energy Corporation stockholders' equity	3,748	3,683
Total Liabilities and Equity	9,397	9,338
Duke Energy Indiana
Current Assets
Cash and cash equivalents	15	25
Receivables (net of allowance for doubtful accounts)	50	60
Receivables from affiliated companies	76	79
Notes receivable from affiliated companies	543
Inventory	538	517
Regulatory assets (includes amounts related to VIEs)	78	90
Other (includes amounts related to VIEs)	36	60
Total current assets	1,336	831
Property, Plant and Equipment
Cost	16,481	16,305
Accumulated depreciation and amortization	(5,349)	(5,233)
Net property, plant and equipment	11,132	11,072
Other Noncurrent Assets
Regulatory assets (includes amounts related to VIEs)	1,098	1,082
Operating lease right-of-use assets, net	57	57
Other (includes amounts related to VIEs)	214	234
Total other noncurrent assets	1,369	1,373
Total Assets	13,837	13,276
Current Liabilities
Accounts payable	157	201
Accounts payable to affiliated companies	66	87
Notes payable to affiliated companies		30
Taxes accrued	81	49
Interest accrued	60	58
Current maturities of long-term debt (includes amounts related to VIEs)	503	503
Asset retirement obligations	181	189
Regulatory liabilities	46	55
Other	92	112
Total current liabilities	1,186	1,284
Long-Term Debt (includes amounts related to VIEs)	3,950	3,404
Long-Term Debt Payable to Affiliated Companies	150	150
Other Noncurrent Liabilities
Deferred income taxes	1,158	1,150
Asset retirement obligations	645	643
Regulatory liabilities	1,672	1,685
Operating lease liabilities	54	55
Accrued pension and other post-retirement benefit costs	148	148
Investment tax credits	170	164
Other (includes amounts related to VIEs)	30	18
Total other noncurrent liabilities	3,877	3,863
Equity
Total member's equity	4,674	4,575
Total Liabilities and Equity	13,837	13,276
Piedmont Natural Gas
Current Assets
Cash and cash equivalents	4
Receivables (net of allowance for doubtful accounts)	191	241
Receivables from affiliated companies	13	10
Inventory	39	72
Regulatory assets (includes amounts related to VIEs)	96	73
Other (includes amounts related to VIEs)	13	28
Total current assets	356	424
Property, Plant and Equipment
Cost	8,653	8,446
Accumulated depreciation and amortization	(1,703)	(1,681)
Net property, plant and equipment	6,950	6,765
Other Noncurrent Assets
Goodwill	49	49
Regulatory assets (includes amounts related to VIEs)	263	290
Operating lease right-of-use assets, net	23	24
Investments in equity method unconsolidated affiliates	84	83
Other (includes amounts related to VIEs)	132	121
Total other noncurrent assets	551	567
Total Assets	7,857	7,756
Current Liabilities
Accounts payable	145	215
Accounts payable to affiliated companies	12	3
Notes payable to affiliated companies	486	476
Taxes accrued	36	24
Interest accrued	32	33
Regulatory liabilities	91	81
Other	54	67
Total current liabilities	856	899
Long-Term Debt (includes amounts related to VIEs)	2,385	2,384
Other Noncurrent Liabilities
Deferred income taxes	742	708
Asset retirement obligations	17	17
Regulatory liabilities	1,087	1,131
Operating lease liabilities	22	23
Accrued pension and other post-retirement benefit costs	7	3
Other (includes amounts related to VIEs)	121	148
Total other noncurrent liabilities	1,996	2,030
Equity
Common stock	1,310	1,310
Retained earnings	1,310	1,133
Total Duke Energy Corporation stockholders' equity	2,620	2,443
Total Liabilities and Equity	7,857	7,756
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, 2020	Dec. 31, 2019
Allowance for doubtful accounts - receivables	$ 28	$ 22
Regulatory Assets: Current	1,770	1,796
Current Assets: Other	1,000	764
Other Noncurrent Assets: Regulatory assets	13,413	13,222
Other, noncurrent assets	3,315	3,289
Current maturities of long-term debt	5,077	3,141
Long-Term Debt	$ 56,311	$ 54,985
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized	2,000,000,000	2,000,000,000
Common stock, shares outstanding	735,000,000	733,000,000
Other, noncurrent liabilities	$ 1,669	$ 1,581
Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	61	54
Regulatory Assets: Current	53	52
Current Assets: Other	300	242
Other Noncurrent Assets: Regulatory assets	980	989
Other, noncurrent assets	87	110
Current maturities of long-term debt	216	216
Long-Term Debt	3,966	3,997
Other, noncurrent liabilities	258	228
Duke Energy Carolinas
Allowance for doubtful accounts - receivables	3	3
Regulatory Assets: Current	524	550
Current Assets: Other	31	21
Other Noncurrent Assets: Regulatory assets	3,427	3,360
Other, noncurrent assets	1,136	1,149
Current maturities of long-term debt	457	458
Long-Term Debt	12,050	11,142
Other, noncurrent liabilities	640	627
Duke Energy Carolinas | Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	8	7
Progress Energy
Allowance for doubtful accounts - receivables	8	7
Regulatory Assets: Current	954	946
Current Assets: Other	196	210
Other Noncurrent Assets: Regulatory assets	6,489	6,346
Other, noncurrent assets	1,121	1,049
Current maturities of long-term debt	1,828	1,577
Long-Term Debt	$ 17,377	$ 17,907
Common stock, par value (in usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100	100
Common stock, shares outstanding	100	100
Other, noncurrent liabilities	$ 404	$ 383
Progress Energy | Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	12	9
Regulatory Assets: Current	53	52
Current Assets: Other	13	39
Other Noncurrent Assets: Regulatory assets	980	989
Current maturities of long-term debt	54	54
Long-Term Debt	1,603	1,632
Duke Energy Progress
Allowance for doubtful accounts - receivables	2	3
Regulatory Assets: Current	503	526
Current Assets: Other	48	60
Other Noncurrent Assets: Regulatory assets	4,392	4,152
Other, noncurrent assets	682	651
Current maturities of long-term debt	1,006	1,006
Long-Term Debt	7,903	7,902
Other, noncurrent liabilities	83	92
Duke Energy Progress | Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	7	5
Duke Energy Florida
Allowance for doubtful accounts - receivables	6	3
Regulatory Assets: Current	451	419
Current Assets: Other	37	58
Other Noncurrent Assets: Regulatory assets	2,097	2,194
Other, noncurrent assets	329	311
Current maturities of long-term debt	322	571
Long-Term Debt	7,384	7,416
Other, noncurrent liabilities	169	136
Duke Energy Florida | Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	5	4
Regulatory Assets: Current	53	52
Current Assets: Other	13	39
Other Noncurrent Assets: Regulatory assets	980	989
Current maturities of long-term debt	54	54
Long-Term Debt	1,278	1,307
Duke Energy Ohio
Allowance for doubtful accounts - receivables	5	4
Regulatory Assets: Current	33	49
Current Assets: Other	11	21
Other Noncurrent Assets: Regulatory assets	567	549
Other, noncurrent assets	56	52
Long-Term Debt	$ 2,595	$ 2,594
Common stock, par value (in usd per share)	$ 8.50	$ 8.50
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares outstanding	90,000,000	90,000,000
Other, noncurrent liabilities	$ 97	$ 94
Duke Energy Indiana
Allowance for doubtful accounts - receivables	3	3
Regulatory Assets: Current	78	90
Current Assets: Other	36	60
Other Noncurrent Assets: Regulatory assets	1,098	1,082
Other, noncurrent assets	214	234
Current maturities of long-term debt	503	503
Long-Term Debt	3,950	3,404
Other, noncurrent liabilities	30	18
Piedmont Natural Gas
Allowance for doubtful accounts - receivables	5	2
Regulatory Assets: Current	96	73
Current Assets: Other	13	28
Other Noncurrent Assets: Regulatory assets	263	290
Other, noncurrent assets	132	121
Long-Term Debt	$ 2,385	$ 2,384
Common stock, shares authorized	100	100
Common stock, shares outstanding	100	100
Other, noncurrent liabilities	$ 121	$ 148
Preferred stock, Series A
Preferred stock, par value (in usd per share)	$ 0.001	$ 0.001
Preferred stock, depositary shares authorized	40,000,000	40,000,000
Preferred stock, depositary shares outstanding	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	1,000,000	1,000,000
Preferred stock, depositary shares outstanding	1,000,000	1,000,000

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income	$ 890	$ 893
Net income (attributable to parent)	938	900
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	1,301	1,238
Equity component of AFUDC	(40)	(31)
(Gains) Losses on sales of other assets	(1)	3
Impairment charges	2
Deferred income taxes	422	97
Equity in earnings of unconsolidated affiliates	(44)	(43)
Payments for asset retirement obligations	(132)	(152)
Provision for rate refunds	(13)	35
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions		10
Receivables	466	388
Inventory	(92)	(31)
Other current assets	(131)	98
Increase (decrease) in
Accounts payable	(657)	(636)
Taxes accrued	113	(107)
Other current liabilities	(455)	(407)
Other assets	(25)	(162)
Other liabilities	(50)	46
Net cash provided by operating activities	1,554	1,239
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(2,832)	(2,536)
Contributions to equity method investments	(77)	(94)
Purchases of debt and equity securities	(1,392)	(860)
Proceeds from sales and maturities of debt and equity securities	1,347	851
Other	(68)	(74)
Net cash used in investing activities	(3,022)	(2,713)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	1,954	2,737
Proceeds from the issuance of preferred stock		974
Proceeds from the issuance of common stock	40	13
Payments for the redemption of long-term debt	(292)	(1,201)
Proceeds from the issuance of short-term debt with original maturities greater than 90 days	1,784	135
Payments for the redemption of short-term debt with original maturities greater than 90 days	(17)	(239)
Notes payable and commercial paper	(198)	(304)
Contributions from noncontrolling interests	103	6
Dividends paid	(707)	(649)
Other	(74)	(39)
Net cash provided by financing activities	2,593	1,433
Net increase (decrease) in cash, cash equivalents and restricted cash	1,125	(41)
Cash, cash equivalents and restricted cash at beginning of period	573	591
Cash, cash equivalents and restricted cash at end of period	1,698	550
Significant non-cash transactions:
Accrued capital expenditures	934	811
Non-cash dividends	27	27
Duke Energy Carolinas
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	339	293
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	414	388
Equity component of AFUDC	(14)	(9)
(Gains) Losses on sales of other assets	(1)
Impairment charges	2
Deferred income taxes	22	64
Payments for asset retirement obligations	(41)	(65)
Provision for rate refunds		19
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions		1
Receivables	156	124
Receivable from affiliated companies	27	94
Inventory	(72)	(59)
Other current assets	96	(35)
Increase (decrease) in
Accounts payable	(253)	(266)
Accounts payable to affiliated companies	15	18
Taxes accrued	87	(91)
Other current liabilities	(108)	(70)
Other assets	(60)	(31)
Other liabilities	(11)	(7)
Net cash provided by operating activities	598	368
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(724)	(721)
Purchases of debt and equity securities	(607)	(405)
Proceeds from sales and maturities of debt and equity securities	607	405
Notes receivable from affiliated companies	(436)
Other	(18)	(9)
Net cash used in investing activities	(1,178)	(730)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	910	25
Payments for the redemption of long-term debt	(2)	(1)
Notes payable to affiliated companies	(29)	306
Distributions to parent	(300)
Other	(1)	(1)
Net cash provided by financing activities	578	329
Net increase (decrease) in cash, cash equivalents and restricted cash	(2)	(33)
Cash, cash equivalents and restricted cash at beginning of period	18	33
Cash, cash equivalents and restricted cash at end of period	16
Significant non-cash transactions:
Accrued capital expenditures	254	221
Progress Energy
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income	283	248
Net income (attributable to parent)	283	249
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	552	546
Equity component of AFUDC	(14)	(15)
(Gains) Losses on sales of other assets	1
Deferred income taxes	80	82
Payments for asset retirement obligations	(79)	(75)
Provision for rate refunds	2	6
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	1	1
Receivables	149	187
Receivable from affiliated companies	27	122
Inventory	(40)	(18)
Other current assets	43	35
Increase (decrease) in
Accounts payable	(211)	(196)
Accounts payable to affiliated companies	19	(94)
Taxes accrued	71	26
Other current liabilities	(128)	(196)
Other assets	(41)	(111)
Other liabilities	(56)	(7)
Net cash provided by operating activities	659	541
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(972)	(1,012)
Purchases of debt and equity securities	(651)	(409)
Proceeds from sales and maturities of debt and equity securities	643	405
Notes receivable from affiliated companies	164	(31)
Other	(39)	(45)
Net cash used in investing activities	(855)	(1,092)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt		1,295
Payments for the redemption of long-term debt	(283)	(1,132)
Notes payable to affiliated companies	479	370
Other	(1)	1
Net cash provided by financing activities	195	534
Net increase (decrease) in cash, cash equivalents and restricted cash	(1)	(17)
Cash, cash equivalents and restricted cash at beginning of period	126	112
Cash, cash equivalents and restricted cash at end of period	125	95
Significant non-cash transactions:
Accrued capital expenditures	310	310
Duke Energy Progress
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	204	203
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	331	336
Equity component of AFUDC	(10)	(14)
(Gains) Losses on sales of other assets	1
Deferred income taxes	43	33
Payments for asset retirement obligations	(75)	(68)
Provision for rate refunds	2	6
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	(2)	(3)
Receivables	133	87
Receivable from affiliated companies	2	(5)
Inventory	(22)	(5)
Other current assets	54	96
Increase (decrease) in
Accounts payable	(220)	(196)
Accounts payable to affiliated companies	5	(57)
Taxes accrued	26	(4)
Other current liabilities	(73)	(109)
Other assets	(51)	(47)
Other liabilities	(8)	(7)
Net cash provided by operating activities	340	246
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(466)	(548)
Purchases of debt and equity securities	(550)	(315)
Proceeds from sales and maturities of debt and equity securities	540	308
Notes receivable from affiliated companies		(38)
Other	(16)	(20)
Net cash used in investing activities	(492)	(613)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt		1,270
Payments for the redemption of long-term debt	(1)	(601)
Notes payable to affiliated companies	163	(294)
Other		(1)
Net cash provided by financing activities	162	374
Net increase (decrease) in cash, cash equivalents and restricted cash	10	7
Cash, cash equivalents and restricted cash at beginning of period	22	23
Cash, cash equivalents and restricted cash at end of period	32	30
Significant non-cash transactions:
Accrued capital expenditures	87	117
Duke Energy Florida
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	120	96
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	219	207
Equity component of AFUDC	(4)	(1)
Deferred income taxes	34	45
Payments for asset retirement obligations	(5)	(7)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	3	2
Receivables	15	55
Receivable from affiliated companies		(6)
Inventory	(19)	(13)
Other current assets	7	(35)
Increase (decrease) in
Accounts payable	11
Accounts payable to affiliated companies	(20)	(62)
Taxes accrued	31	20
Other current liabilities	(58)	(84)
Other assets	13	(63)
Other liabilities	(46)	(1)
Net cash provided by operating activities	301	153
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(506)	(422)
Purchases of debt and equity securities	(101)	(95)
Proceeds from sales and maturities of debt and equity securities	103	97
Notes receivable from affiliated companies	173
Other	(23)	(25)
Net cash used in investing activities	(354)	(445)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt		25
Payments for the redemption of long-term debt	(282)	(81)
Notes payable to affiliated companies	305	291
Other	(1)	2
Net cash provided by financing activities	22	237
Net increase (decrease) in cash, cash equivalents and restricted cash	(31)	(55)
Cash, cash equivalents and restricted cash at beginning of period	56	75
Cash, cash equivalents and restricted cash at end of period	25	20
Significant non-cash transactions:
Accrued capital expenditures	223	193
Duke Energy Ohio
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	65	69
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	69	65
Equity component of AFUDC	(1)	(3)
Deferred income taxes	14	20
Payments for asset retirement obligations		(1)
Provision for rate refunds	3	4
(Increase) decrease in
Receivables	1	5
Receivable from affiliated companies	40	35
Inventory	14	15
Other current assets	8	(6)
Increase (decrease) in
Accounts payable	(19)	(5)
Accounts payable to affiliated companies		(8)
Taxes accrued	(49)	(45)
Other current liabilities	2	14
Other assets	(2)	(10)
Other liabilities	(8)	(4)
Net cash provided by operating activities	137	145
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(217)	(233)
Notes receivable from affiliated companies		(463)
Other	(10)	(11)
Net cash used in investing activities	(227)	(707)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt		794
Notes payable to affiliated companies	87	(236)
Net cash provided by financing activities	87	558
Net increase (decrease) in cash, cash equivalents and restricted cash	(3)	(4)
Cash, cash equivalents and restricted cash at beginning of period	17	21
Cash, cash equivalents and restricted cash at end of period	14	17
Significant non-cash transactions:
Accrued capital expenditures	66	68
Duke Energy Indiana
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	99	110
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	133	132
Equity component of AFUDC	(6)	(4)
(Gains) Losses on sales of other assets		3
Deferred income taxes	16	28
Payments for asset retirement obligations	(12)	(11)
(Increase) decrease in
Receivables	15	4
Receivable from affiliated companies	3	20
Inventory	(21)	(13)
Other current assets	25	19
Increase (decrease) in
Accounts payable	(13)	8
Accounts payable to affiliated companies	(21)	(11)
Taxes accrued	43	20
Other current liabilities	(27)	(15)
Other assets	(4)	12
Other liabilities	8	6
Net cash provided by operating activities	238	308
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(210)	(208)
Purchases of debt and equity securities	(5)	(6)
Proceeds from sales and maturities of debt and equity securities	2	4
Notes receivable from affiliated companies	(543)
Other	(6)	(11)
Net cash used in investing activities	(762)	(221)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	544
Payments for the redemption of long-term debt		(60)
Notes payable to affiliated companies	(30)	(31)
Net cash provided by financing activities	514	(91)
Net increase (decrease) in cash, cash equivalents and restricted cash	(10)	(4)
Cash, cash equivalents and restricted cash at beginning of period	25	24
Cash, cash equivalents and restricted cash at end of period	15	20
Significant non-cash transactions:
Accrued capital expenditures	70	76
Piedmont Natural Gas
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	178	122
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	46	42
Equity component of AFUDC	(5)
Deferred income taxes	12	23
Equity in earnings of unconsolidated affiliates	(2)	(2)
Provision for rate refunds	(18)	7
(Increase) decrease in
Receivables	65	27
Receivable from affiliated companies	(3)	12
Inventory	33	45
Other current assets	(9)	22
Increase (decrease) in
Accounts payable	(76)	(44)
Accounts payable to affiliated companies	9	(4)
Taxes accrued	12	(49)
Other current liabilities	(12)	15
Other assets	1	(3)
Other liabilities	(1)	(5)
Net cash provided by operating activities	230	208
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(231)	(209)
Other	(5)	(2)
Net cash used in investing activities	(236)	(211)
CASH FLOWS FROM FINANCING ACTIVITIES
Notes payable to affiliated companies	10	3
Net cash provided by financing activities	10	3
Net increase (decrease) in cash, cash equivalents and restricted cash	4
Cash, cash equivalents and restricted cash at end of period	4
Significant non-cash transactions:
Accrued capital expenditures	$ 114	$ 92

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Changes in Equity - USD ($) $ in Millions	Total		Preferred Stock	Common Stockholders' Equity		Common Stock	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 Natural Gas	Piedmont Natural GasCommon Stock	Piedmont Natural GasRetained Earnings	Preferred stock, Series A		Preferred stock, Series APreferred Stock		Preferred stock, Series ACommon Stockholders' Equity	[1]	Preferred stock, Series B	Common Stock	Common StockCommon Stockholders' Equity	Common StockCommon Stock	Common StockAdditional Paid-in Capital
Beginning Balance at Dec. 31, 2018	$ 43,834			$ 43,817		$ 1	$ 40,795		$ 3,113		$ (14)		$ (3)		$ (75)		$ 17								$ 14,257	$ 14,254	$ 9,143	$ 5,131		$ (12)		$ (1)	$ (7)		$ 3
Beginning Balance, in shares at Dec. 31, 2018						727,000,000
Beginning Balance (member's equity) at Dec. 31, 2018																			$ 11,683		$ 11,689		$ (6)														$ 8,441	$ 6,095	$ 6,097	$ (2)						$ 4,339
Beginning Balance (parent) at Dec. 31, 2018																																									$ 3,445	$ 762	$ 2,776	$ (93)			$ 2,091	$ 1,160	$ 931
Net income (attributable to parent)	900																		293		293				249											$ 203	203	96	96		69			69	$ 110	110	122		122
Net Income	893																								248	249		249							(1)
Net income	893			900					900								(7)
Other comprehensive income (loss)	(12)			(12)							(16)		4												3	3				2			1					1		1
Stock issuances																																																		$ 974	[1]	$ 974	[1]	$ 974			$ 28	$ 28		$ 28
Stock issuances, in shares																																																				40,000,000							1,000,000
Common stock dividends	(676)			(676)					(676)
Other	4	[2]		(1)	[2]				23	[2]	(6)	[2]	(1)	[2]	(17)	[2]	5	[2]	(1)				(1)					6	[3]	(4)	[3]		(2)	[3]
Ending Balance at Mar. 31, 2019	45,045		$ 974	45,030		$ 1	40,823		3,360		(36)				(92)		15								14,508	14,506	9,143	5,386		(14)		(1)	(8)		2
Ending Balance, in shares at Mar. 31, 2019						728,000,000
Ending Balance (member's equity) at Mar. 31, 2019																			11,975		11,982		(7)														8,644	6,192	6,193	(1)						4,449
Ending Balance (parent) at Mar. 31, 2019																																									$ 3,514	762	2,776	(24)			$ 2,213	1,160	1,053
Beginning Balance at Dec. 31, 2019	$ 47,951		1,962	46,822		$ 1	40,881		4,108		(51)		3		(82)		1,129								$ 15,593	15,590	9,143	6,465		(10)		(1)	(7)		3
Beginning Balance, in shares at Dec. 31, 2019	733,000,000					733,000,000																			100																90,000,000						100
Beginning Balance, in shares at Dec. 31, 2019																																																		40,000,000						1,000,000
Beginning Balance (member's equity) at Dec. 31, 2019																			12,811		12,818		(7)													9,246	9,246	6,788	6,789	(1)					4,575	4,575
Beginning Balance (parent) at Dec. 31, 2019	$ 46,822																								$ 15,590																$ 3,683	762	2,776	145			$ 2,443	1,310	1,133
Net income (attributable to parent)	938																		339		339				283											204	204	120	120		$ 65			65	99	99	178		178
Net Income	890																								283	283		283
Net income	851			899					899								(48)
Other comprehensive income (loss)	(77)	[4]		(63)							(65)		1		1		(14)								2	2				1		$ 1						1		$ 1
Stock issuances																																																									$ 50	$ 50		$ 50
Stock issuances, in shares																																																											2,000,000
Common stock dividends	(695)			(695)					(695)										(300)		(300)
Contribution from noncontrolling interest in subsidiaries	103																103
Distributions to noncontrolling interest in subsidiaries	(7)																(7)
Other	(93)	[5]		(92)	[5]		(1)	[5]	(91)	[5]							(1)	[5]	(13)	[6]	(13)	[6]	0	[6]	(1)	(1)		(1)																			$ (1)		(1)
Ending Balance at Mar. 31, 2020	$ 48,083		$ 1,962	$ 46,921		$ 1	$ 40,930		$ 4,221		$ (116)		$ 4		$ (81)		$ 1,162								$ 15,877	$ 15,874	$ 9,143	$ 6,747		$ (9)			$ (7)		$ 3
Ending Balance, in shares at Mar. 31, 2020																																																		40,000,000						1,000,000
Ending Balance, in shares at Mar. 31, 2020	735,000,000					735,000,000																			100																90,000,000						100
Ending Balance (member's equity) at Mar. 31, 2020																			$ 12,837		$ 12,844		$ (7)													$ 9,450	$ 9,450	$ 6,909	$ 6,909						$ 4,674	$ 4,674
Ending Balance (parent) at Mar. 31, 2020	$ 46,921																								$ 15,874																$ 3,748	$ 762	$ 2,776	$ 210			$ 2,620	$ 1,310	$ 1,310
[1]	Duke Energy issued 40 million depositary shares of preferred stock, Series A.
[2]	Amounts in Retained Earnings and Accumulated Other Comprehensive (Loss) Income primarily represent impacts to accumulated other comprehensive income due to implementation of a new accounting standard related to Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income.
[3]	Amounts in Retained Earnings and Accumulated Other Comprehensive Loss primarily represent impacts to accumulated other comprehensive income due to implementation of a new accounting standard related to Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income.
[4]	Net of income tax impact of approximately $23 million in the first quarter of 2020 and immaterial income tax impact in the first quarter of 2019.
[5]	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.
[6]	Amounts primarily represent impacts due to implementation of a new accounting standard related to Current Estimated Credit Losses. See Note 1 for additional discussion.

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Changes in Equity (Parenthetical)	3 Months Ended
	Mar. 31, 2019shares
Preferred stock, Series A | Preferred Stock
Stock issuances, in shares	40,000,000

Organization and Basis of Prese

Organization and Basis of Presentation	3 Months Ended
	Mar. 31, 2020
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, 2019 . 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. COVID-19 The COVID-19 pandemic is having a significant impact on global health and economic environments. In March 2020, the World Health Organization (WHO) declared COVID-19 a global pandemic, and President Trump proclaimed that the COVID-19 outbreak in the United States constitutes a national emergency. The COVID-19 pandemic has not had a material financial impact on the Duke Energy Registrants as of March 31, 2020; however, the extent to which the COVID-19 pandemic will impact the Duke Energy Registrants during 2020 and beyond is uncertain at this time. The Duke Energy Registrants are monitoring developments closely. See Notes 3 , 5 , 11 , 12 and 15 for information on COVID-19 and steps taken to mitigate the impacts to our business and customers. 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, 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. Duke Energy has received $103 million for the sale of noncontrolling interests to tax equity members for the three months ended March 31, 2020 . Duke Energy allocated approximately $49 million and $7 million of losses to noncontrolling tax equity members utilizing the HLBV method for the three months ended March 31, 2020 , and March 31, 2019 , respectively. 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 . 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 Note 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, 2020 December 31, 2019 Duke Duke Duke Progress Energy Duke Progress Energy Energy Energy Florida Energy Energy Florida Current Assets Cash and cash equivalents $ 1,450 $ 52 $ 12 $ 311 $ 48 $ 17 Other 185 13 13 222 39 39 Other Noncurrent Assets Other 63 60 — 40 39 — Total cash, cash equivalents and restricted cash $ 1,698 $ 125 $ 25 $ 573 $ 126 $ 56 INVENTORY Provisions for inventory write-offs were not material at March 31, 2020 , and December 31, 2019 . The components of inventory are presented in the tables below. 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 Materials and supplies $ 2,280 $ 759 $ 1,018 $ 678 $ 340 $ 83 $ 319 $ 5 Coal 742 268 246 167 79 10 218 — Natural gas, oil and other fuel 302 40 199 111 89 28 1 34 Total inventory $ 3,324 $ 1,067 $ 1,463 $ 956 $ 508 $ 121 $ 538 $ 39 December 31, 2019 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 $ 2,297 $ 768 $ 1,038 $ 686 $ 351 $ 79 $ 318 $ 5 Coal 586 187 186 138 48 15 198 — Natural gas, oil and other fuel 349 41 199 110 90 41 1 67 Total inventory $ 3,232 $ 996 $ 1,423 $ 934 $ 489 $ 135 $ 517 $ 72 NEW ACCOUNTING STANDARDS The following new accounting standard was adopted by the Duke Energy Registrants in 2020 . Current Expected Credit Losses. In June 2016, the 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, 2020 . 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.

Business Segments

Business Segments	3 Months Ended
	Mar. 31, 2020
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. 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 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, 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) (a) $ 705 $ 249 $ 57 $ 1,011 $ (112 ) $ — $ 899 Add: Noncontrolling interests (b) (48 ) Add: Preferred stock dividend 39 Net income $ 890 Segment assets $ 134,838 $ 14,098 $ 6,184 $ 155,120 $ 4,964 $ (12 ) $ 160,072 Three Months Ended March 31, 2019 Electric Gas Total Utilities and Utilities and Commercial Reportable (in millions) Infrastructure Infrastructure Renewables Segments Other Eliminations Total Unaffiliated revenues $ 5,321 $ 732 $ 106 $ 6,159 $ 4 $ — $ 6,163 Intersegment revenues 8 24 — 32 17 (49 ) — Total revenues $ 5,329 $ 756 $ 106 $ 6,191 $ 21 $ (49 ) $ 6,163 Segment income (loss) $ 750 $ 226 $ 13 $ 989 $ (89 ) $ — $ 900 Add: Noncontrolling interests (b) (7 ) Net income $ 893 (a) Other includes a $98 million reversal, included in Operations, maintenance and other on the Condensed Consolidated Statements of Operations, of 2018 severance costs due to the partial settlement of the Duke Energy Carolina's 2019 North Carolina rate case. See Note 3 for additional information. (b) Includes the allocation of losses to noncontrolling tax equity members. See Note 1 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, 2020 Electric Gas Total Utilities and Utilities and Reportable (in millions) Infrastructure Infrastructure Segments Other Eliminations Total Total revenues $ 346 $ 152 $ 498 $ — $ — $ 498 Segment income/Net (loss) income $ 30 $ 36 $ 66 $ (1 ) $ — $ 65 Segment assets $ 6,238 $ 3,135 $ 9,373 $ 26 $ (2 ) $ 9,397 Three Months Ended March 31, 2019 Electric Gas Total Utilities and Utilities and Reportable (in millions) Infrastructure Infrastructure Segments Other Total Total revenues $ 355 $ 176 $ 531 $ — $ 531 Segment income/Net (loss) income $ 36 $ 35 $ 71 $ (2 ) $ 69

Regulatory Matters

Regulatory Matters	3 Months Ended
	Mar. 31, 2020
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 COVID-19 Filings North Carolina On March 10, 2020, Governor Roy Cooper issued Executive Order No. 116 declaring a state of emergency due to the COVID-19 pandemic. In an effort to help mitigate the financial impacts of the COVID-19 pandemic on their customers, on March 19, 2020, Duke Energy Carolinas and Duke Energy Progress filed a request with the NCUC seeking authorization to waive: (1) any late payment charges incurred by a residential or nonresidential customer, effective March 21, 2020; (2) the application of fees for checks returned for insufficient funds for residential and nonresidential customers; (3) the reconnection charge when a residential or nonresidential customer seeks to have service restored for those customers whose service was recently disconnected for nonpayment and to work with customers regarding the other requirements to restore service, including re-establishment of credit; and (4) the fees and charges associated with the use of credit cards or debit cards to pay residential electric utility bills, effective March 21, 2020. The NCUC granted the companies’ request on March 20, 2020. On March 31, 2020, the governor issued Executive Order No. 124, which, in addition to requiring the steps in the NCUC order noted above, stated that nothing in Executive Order No. 124 shall relieve a customer of its obligation to pay bills for receipt of utility services provided. Executive Order No. 124 remains in effect for 60 days unless otherwise rescinded or replaced with a superseding Executive Order. On March 31, 2020, the Carolina Utility Customers Association (CUCA) filed a petition with the NCUC to temporarily suspend minimum demand charges for commercial and industrial customers. On April 2, 2020, the NCUC issued an order requiring the North Carolina Public Staff (Public Staff) and Duke Energy Carolinas, Duke Energy Progress and other utilities to file responses. On April 9, 2020, Duke Energy Carolinas and Duke Energy Progress filed responses to CUCA’s petition opposing CUCA’s request. The companies assert that voiding commission-approved tariffs and allowing all commercial and industrial customers on the requested rate schedules to avoid paying a portion of their bills is not legally permissible and would result in these costs unfairly being shifted to other customers that are already paying their respective fair share of similar fixed components. Pursuant to the NCUC’s April 2 order, reply comments were filed by CUCA, the Public Staff and Duke Energy Carolinas and Duke Energy Progress on April 15, 2020. A final order from the NCUC deciding CUCA's request is pending. Duke Energy Carolinas and Duke Energy Progress cannot predict the outcome of this matter. South Carolina On March 13, 2020, Governor Henry McMaster issued Executive Order No. 2020-08 declaring a state of emergency due to the COVID-19 pandemic. The governor also issued a letter on March 14, 2020, to the ORS Executive Director regarding the suspension of disconnection of essential utility services for nonpayment. On March 16, 2020, citing the governor’s letter, the ORS filed a request asking the PSCSC to grant waivers so that utilities could suspend disconnections of utility services for nonpayment. Duke Energy Carolinas and Duke Energy Progress supported such motion. On March 18, 2020, the PSCSC issued an order approving such waivers, and also approved waivers for regulations related to late fees and reconnect fees. The PSCSC's order also required utilities to track the financial impacts of actions taken pursuant to such waivers for possible reporting to the PSCSC. On April 30, 2020, the ORS requested the PSCSC grant a waiver of the applicable regulations to allow customers the flexibility to obtain deferred payment plans longer than 6 months for past-due amounts. On May 5, 2020, Duke Energy Carolinas and Duke Energy Progress filed responsive comments stating that while utility bills will remain due, Duke Energy Carolinas and Duke Energy Progress do not plan to immediately reinstitute disconnection upon the expiration of the state of emergency and intend to work through a potential grace period as economic recovery begins. Duke Energy Carolinas and Duke Energy Progress also concurred with the observation of the ORS that reduced usage is impacting the fixed cost recovery and revenue assumptions included in rates. Those costs include not only ongoing operational and financing costs necessary to serve customers, but also the borrowings necessary to support extended payment arrangements that will be an important part of emerging from the COVID-19 pandemic. Duke Energy Carolinas and Duke Energy Progress will continue to track such costs, lost revenues and potential cost savings for future evaluation by the PSCSC. Additionally, on May 8, 2020, the ORS filed a motion for the PSCSC to solicit comments from utilities and interested stakeholders regarding measures to be taken to mitigate impacts of COVID-19 on utility customers and require recordkeeping. In a detailed motion, the ORS specifically asked the PSCSC to: (1) solicit input from utilities regarding the temporary mitigation measures to address COVID-19; (2) request utilities to inform the PSCSC of the plans utilities have to return to normalized operations; (3) require utilities to track revenue impacts, incremental costs and savings related to COVID-19 and file the findings with the PSCSC on a quarterly basis; and (4) include any other matters that the PSCSC believes should be addressed. The ORS requests that such comments be filed within 30 days of a PSCSC order approving the motion. 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 , which represented an approximate 13.6% increase in annual base revenues. The request for rate increase was driven by capital investments subsequent to the previous base rate case, including the William States Lee Combined Cycle Facility, grid improvement projects, AMI, investments in customer service technologies, costs of complying with CCR regulations and the Coal Ash Act and recovery of costs related to licensing and development of the William States Lee III Nuclear Station. 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 a return on equity 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. On July 20, 2018, the North Carolina Attorney General filed a Notice of Appeal to the North Carolina Supreme Court from the June 22, 2018, Order Accepting Stipulation, Deciding Contested Issues and Requiring Revenue Reduction issued by the NCUC. The Attorney General contends the commission’s order should be reversed and remanded, as it is in excess of the commission’s statutory authority; affected by errors of law; unsupported by competent, material and substantial evidence in view of the entire record as submitted; and arbitrary or capricious. The Sierra Club, North Carolina Sustainable Energy Association, North Carolina Justice Center, North Carolina Housing Coalition, Natural Resource Defense Council and Southern Alliance for Clean Energy also filed Notices of Appeal to the North Carolina Supreme Court. On August 8, 2018, the Public Staff filed a Notice of Cross Appeal to the North Carolina Supreme Court, which contends the commission’s June 22, 2018, order should be reversed and remanded, as it is affected by errors of law, and is unsupported by substantial evidence with regard to the commission’s failure to consider substantial evidence of coal ash related environmental violations. On November 29, 2018, the North Carolina Attorney General's Office filed a motion with the North Carolina Supreme Court requesting the court consolidate the Duke Energy Carolinas and Duke Energy Progress appeals and enter an order adopting the parties’ proposed briefing schedule as set out in the filing. On November 29, 2018, the North Carolina Supreme Court adopted a schedule for briefing set forth in the motion to consolidate the Duke Energy Carolinas and Duke Energy Progress appeals. Appellant briefs were filed on April 26, 2019. The Appellee response briefs were filed on September 25, 2019. Oral arguments before the North Carolina Supreme Court were held on March 11, 2020. Duke Energy Carolinas cannot predict the outcome of this matter. 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 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, which is subject to review and approval of the NCUC, resolving certain issues in the base rate proceeding. Major components of the settlement included: • Removal of deferred storm costs from the rate case; • Filing a petition seeking to securitize the deferred storm costs within 120 days of a commission order in this rate case regarding the reasonableness and prudency of the storm costs; • Agreement of certain assumptions to demonstrate the quantifiable benefits to customers of a securitization financing; and • Agreement on certain accounting matters, including recovery of employee incentives, severance, aviation costs and executive compensation. On May 6, 2020, Duke Energy Carolinas, Duke Energy Progress and the Public Staff filed a joint motion requesting that the NCUC issue an order scheduling one consolidated evidentiary hearing to consider the companies’ applications for net rate increases. The joint motion suggests, health and safety permitting, that the commission consider the possibility of holding the consolidated hearing in July. If the NCUC grants the joint motion, Duke Energy Carolinas expects the NCUC to issue an order on its net rate increase by the end of the year. Duke Energy Carolinas cannot predict the outcome of this matter. 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 , which represented an approximate 10% increase in retail revenues. The request for rate increase was driven by capital investments and environmental compliance progress made by Duke Energy Carolinas since its previous rate case, including the further implementation of Duke Energy Carolinas’ generation modernization program, which consists of retiring, replacing and upgrading generation plants, investments in customer service technologies and continued investments in base work to maintain its transmission and distribution systems. The request included net tax benefits resulting from the Tax Act of $66 million to reflect the change in ongoing tax expense, primarily from the reduction in the federal income tax rate from 35% to 21%. The request also included $46 million to return EDIT resulting from the federal tax rate change and deferred revenues since January 2018 related to the change and benefits of $17 million from a reduction in North Carolina state income taxes allocable to South Carolina (EDIT Rider). Duke Energy Carolinas also requested approval of its proposed Grid Improvement Plan (GIP), adjustments to its Prepaid Advantage Program and a variety of accounting orders related to ongoing costs for environmental compliance, including recovery over a five -year period of $242 million of deferred coal ash related compliance costs, grid investments between rate changes, incremental depreciation expense, a result of new depreciation rates from the depreciation study approved in the 2017 North Carolina Rate Case above, and the balance of development costs associated with the cancellation of the Lee Nuclear Project. Finally, Duke Energy Carolinas sought approval to establish a reserve and accrual for end-of-life nuclear costs for nuclear fuel and materials and supplies. On March 8, 2019, the ORS moved to establish a new and separate hearing docket to review and consider the GIP proposed by Duke Energy Carolinas. Subsequently, on March 12, 2019, the ORS and Duke Energy Carolinas executed a Stipulation resolving the ORS’s motion. The Stipulation provided that costs incurred for the GIP after January 1, 2019, would be deferred with a return, subject to evaluation in a future rate proceeding. The Stipulation was approved by the PSCSC on June 19, 2019. On December 16, 2019, Duke Energy Carolinas and Duke Energy Progress filed a Joint Petition to Establish an Informational Docket for Review and Consideration of Grid Improvement Plans through which Duke Energy Carolinas and Duke Energy Progress would provide interested stakeholders information on the companies' grid activities. The PSCSC requested parties comment on procedural matters by January 31, 2020; accordingly, various groups filed comments, none of which opposed an informational docket. Duke Energy Carolinas cannot predict the outcome of this matter. After hearings in March 2019, the PSCSC issued an order on May 21, 2019, which included a return on equity 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 commission 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, return on equity 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 and the ORS filed a Notice of Cross Appeal with the Supreme Court of South Carolina. On February 12, 2020, Duke Energy Carolinas and the ORS filed a joint motion to extend briefing schedule deadlines, which was approved by the Supreme Court of South Carolina on February 20, 2020. On March 10, 2020, the ORS filed a consent motion requesting withdrawal of their appeal. Initial briefs were filed on April 21, 2020. Response briefs and reply briefs are due July 6, 2020, and August 11, 2020, respectively. Also on April 21, 2020, the South Carolina Energy User's Committee filed a brief arguing that the PSCSC erred in allowing Duke Energy Carolinas' recovery of costs related to the Lee Nuclear Station. Based on legal analysis and the filing of the appeal, Duke Energy Carolinas has not recorded an adjustment for its deferred coal ash costs. 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 represented an approximate 14.9% increase in annual base revenues. Subsequent to the filing, Duke Energy Progress adjusted the requested amount to $420 million , representing an approximate 13% increase. The request for rate increase was driven by capital investments subsequent to the previous base rate case, costs of complying with CCR regulations and the Coal Ash Act, costs relating to storm recovery, investments in customer service technologies and recovery of costs associated with renewable purchased power. 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 a return on equity 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. On May 15, 2018, the Public Staff filed a Notice of Cross Appeal to the North Carolina Supreme Court from the NCUC's February 23, 2018, order. The Public Staff contends the NCUC’s order should be reversed and remanded, as it is affected by errors of law, and is unsupported by competent, material and substantial evidence in view of the entire record as submitted. The North Carolina Attorney General and Sierra Club also filed Notices of Appeal to the North Carolina Supreme Court from the February 23, 2018, order. On November 29, 2018, the North Carolina Attorney General's Office filed a motion with the North Carolina Supreme Court requesting the court consolidate the Duke Energy Progress and Duke Energy Carolinas appeals and enter an order adopting the parties’ proposed briefing schedule as set out in the filing. Appellant briefs were filed on April 26, 2019. The Appellee response briefs were filed on September 25, 2019. Oral arguments before the North Carolina Supreme Court were held on March 11, 2020. Duke Energy Progress cannot predict the outcome of this matter. 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 seeks to defer and recover incremental Hurricane Dorian storm costs in this proceeding and requests 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 May 6, 2020, Duke Energy Progress, Duke Energy Carolinas and the Public Staff filed a joint motion requesting that the NCUC issue an order scheduling one consolidated evidentiary hearing to consider the companies’ applications for net rate increases. The joint motion suggests, health and safety permitting, that the commission consider the possibility of holding the consolidated hearing in July. If the NCUC grants the joint motion, Duke Energy Progress expects the NCUC to issue an order on its net rate increase by the end of the year. Duke Energy Progress cannot predict the outcome of this matter. Hurricane Dorian Hurricane Dorian reached the Carolinas in September 2019 as a Category 2 hurricane making landfall within Duke Energy Progress’ service territory. Approximately 270,000 North Carolina customers and 30,000 South Carolina customers were impacted by the slow-moving storm that brought high winds, tornadoes and heavy rain. With storm-response mobilization occurring in preparation for the storm and the assistance of mutual aid partners, full restoration was accomplished within four days for all customers able to receive service. Total estimated incremental operation and maintenance expenses incurred to repair and restore the system are approximately $177 million with an additional $4 million in capital investments made for restoration efforts. Approximately $151 million and $179 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, 2020, and December 31, 2019, respectively. 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. Duke Energy Progress cannot predict the outcome of this matter. On February 7, 2020, a petition was filed with the PSCSC in the 2019 storm deferrals docket requesting deferral of approximately $22 million in operation and maintenance expenses to an existing storm deferral balance previously approved by the PSCSC. The PSCSC voted to approve the request on March 4, 2020, and issued a final order on April 7, 2020. 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 , which represented an approximate 10.3% increase in annual base revenues. The request for rate increase was driven by capital investments and environmental compliance progress made by Duke Energy Progress since its previous rate case, including the further implementation of Duke Energy Progress’ generation modernization program, which consists of retiring, replacing and upgrading generation plants, investments in customer service technologies and continued investments in base work to maintain its transmission and distribution systems. The request included a decrease resulting from the Tax Act of $17 million to reflect the change in ongoing tax expense, primarily the reduction in the federal income tax rate from 35% to 21%. The request also included $10 million to return EDIT resulting from the federal tax rate change and deferred revenues since January 2018 related to the change (EDIT Rider) and a $12 million increase due to the expiration of EDITs related to reductions in North Carolina state income taxes allocable to South Carolina. Duke Energy Progress also requested approval of its proposed GIP, approval of a Prepaid Advantage Program and a variety of accounting orders related to ongoing costs for environmental compliance, including recovery over a five -year period of $51 million of deferred coal ash related compliance costs, AMI deployment, grid investments between rate changes and regulatory asset treatment related to the retirement of a generating plant located in Asheville, North Carolina. Finally, Duke Energy Progress sought approval to establish a reserve and accrual for end-of-life nuclear costs for materials and supplies and nuclear fuel. On March 8, 2019, the ORS moved to establish a new and separate hearing docket to review and consider the GIP proposed by Duke Energy Progress. Subsequently, on March 12, 2019, the ORS and Duke Energy Carolinas executed a Stipulation resolving the ORS’s motion, and Duke Energy Progress agreed to the Stipulation, as did other parties in the rate case. The Stipulation provided that costs incurred for the GIP after January 1, 2019, would be deferred with a return, with all costs subject to evaluation in a future rate proceeding, and that Duke Energy Progress would refile for consideration of the GIP in a new docket for resolution by January 1, 2020. The Stipulation was approved by the PSCSC on June 19, 2019. On December 16, 2019, Duke Energy Progress and Duke Energy Carolinas filed a Joint Petition to Establish an Informational Docket for Review and Consideration of Grid Improvement Plans through which Duke Energy Progress and Duke Energy Carolinas would provide interested stakeholders information on the companies' grid activities. The PSCSC requested parties comment on procedural matters by January 31, 2020; accordingly, various groups filed comments, none of which opposed an informational docket. Duke Energy Progress cannot predict the outcome of this matter. After hearings in April 2019, the PSCSC issued an order on May 21, 2019, which included a return on equity 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 commission 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, return on equity 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. The ORS filed a Notice of Cross Appeal on November 20, 2019. On February 12, 2020, Duke Energy Progress and the ORS filed a joint motion to extend briefing schedule deadlines, which was approved by the Supreme Court of South Carolina on February 20, 2020. On March 10, 2020, the ORS filed a consent motion requesting withdrawal of their appeal. Initial briefs were filed on April 21, 2020. Response briefs and reply briefs are due July 6, 2020, and August 11, 2020, respectively. Based on legal analysis and the filing of the appeal, Duke Energy Progress has not recorded an adjustment for its deferred coal ash costs. Duke Energy Progress cannot predict the outcome of this matter. Western Carolinas Modernization Plan On November 4, 2015, Duke Energy Progress announced a Western Carolinas Modernization Plan, which included retirement of the existing Asheville coal-fired plant, the construction of two 280‑MW combined-cycle natural gas plants having dual-fuel capability, with the option to build a third natural gas simple cycle unit in 2023 based upon the outcome of initiatives to reduce the region's power demand. The plan also included upgrades to existing transmission lines and substations, installation of solar generation and a pilot battery storage project. Duke Energy Progress retired the 376 -MW Asheville coal-fired plant on January 29, 2020, at which time the net book value, including associated ash basin closure costs, of $214 million was transferred from Generation facilities to be retired, net to Regulatory assets within Current Assets and Other Noncurrent Assets on the Condensed Consolidated Balance Sheets. On March 28, 2016, the NCUC issued an order approving a Certificate of Public Convenience and Necessity (CPCN) for the new combined-cycle natural gas plants with an estimated cost of $893 million , but required Duke Energy Progress to refile for CPCN approval for the contingent simple cycle unit. On December 27, 2019, Asheville Combined Cycle Power Block 1 and the common systems that serve both combined cycle units went into commercial operation. Power Block 1 consists of the Unit 5 Combustion Turbine and Unit 6 Steam Turbine Generator (which together form the first combined cycle unit approved in the CPCN Order). Power Block 2 consists of the Unit 7 Combustion Turbine and Unit 8 Steam Turbine Generator (which together form the second combined cycle unit approved in the CPCN Order). Duke Energy Progress placed the Unit 7 Combustion Turbine portion of Power Block 2 into commercial operation in simple-cycle mode on January 15, 2020. The Unit 8 Steam Turbine Generator went into commercial operation on April 5, 2020. 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. On March 22, 2019, Duke Energy Progress

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2020
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. 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 Balance at beginning of period $ 58 $ 11 $ 16 $ 4 $ 9 $ 19 $ 4 $ 8 Provisions/adjustments 3 — — 1 — 1 1 — Cash reductions (3 ) (1 ) (1 ) — — (1 ) — — Balance at end of period $ 58 $ 10 $ 15 $ 5 $ 9 $ 19 $ 5 $ 8 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 $ 58 Duke Energy Carolinas 11 Duke Energy Ohio 41 Piedmont 2 LITIGATION 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 North Carolina Superior 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 EPA CCR rule at 15 coal-fired plants in North Carolina and South Carolina. Despite a stay of the litigation from May 2019 through September 2019 to allow the parties to discuss potential resolution, no resolution was reached, and litigation resumed. In February and March 2020, the court heard arguments on numerous cross motions filed by the parties to seek legal determinations concerning several insurance related defenses raised by the insurance providers. Trial is scheduled for February 2021. Duke Energy Carolinas and Duke Energy Progress cannot predict the outcome of this matter. Duke Energy Carolinas 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, 2020 , there were 118 asserted claims for non-malignant cases with cumulative relief sought of up to $30 million , and 51 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 Carolinas has recognized asbestos-related reserves of $596 million at March 31, 2020 , and $604 million at December 31, 2019 . 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 2039 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 2039 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 $747 million in excess of the self-insured retention. Receivables for insurance recoveries were $742 million at March 31, 2020 , and $742 million at December 31, 2019 . 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. 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 $203 million for Duke Energy Progress and Duke Energy Florida, respectively. Discovery is ongoing and a trial is expected to occur in early 2021. Duke Energy Indiana Coal Ash Basin Closure Plan Appeal On January 27, 2020, Hoosier Environmental Council filed a Petition for Administrative Review with the Indiana Office of Environmental Adjudication (the court) 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 entered an order denying that motion. The court will schedule a trial on the merits for a future date. Duke 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, 2020 December 31, 2019 Reserves for Legal Matters Duke Energy $ 61 $ 62 Duke Energy Carolinas 3 2 Progress Energy 52 55 Duke Energy Progress 9 12 Duke Energy Florida 23 22 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. In addition, the Duke Energy Registrants enter into various fixed-price, noncancelable commitments to purchase or sell power or natural gas, take-or-pay arrangements, transportation, or throughput agreements and other contracts that may or may not be recognized on their respective Condensed Consolidated Balance Sheets. Some of these arrangements may be recognized at fair value on their respective Condensed Consolidated Balance Sheets if such contracts meet the definition of a derivative and the NPNS exception does not apply. In most cases, the Duke Energy Registrants’ purchase obligation contracts contain provisions for price adjustments, minimum purchase levels and other financial commitments. 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. Insurance receivables are 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. The reserve for credit losses for financial guarantees based on adoption of the new standard is $99 million for Duke Energy. Management considers financial guarantees for evaluation under this standard based on the anticipated amount outstanding at the time of default. The reserve for credit losses is based on the evaluation of the contingent components of financial guarantees. Management evaluates the risk of default, exposure and length of time remaining in the period for each contract.

Debt and Credit Facilities

Debt and Credit Facilities	3 Months Ended
	Mar. 31, 2020
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, 2020 Duke Duke Duke Maturity Interest Duke Energy Energy Energy Issuance Date Date Rate Energy (Parent) Carolinas Indiana Unsecured Debt March 2020 (a) March 2021 1.400 % (b) $ 1,688 $ 1,688 $ — $ — First Mortgage Bonds January 2020 (c) February 2030 2.450 % 500 — 500 — January 2020 (c) August 2049 3.200 % 400 — 400 — March 2020 (d) April 2050 2.750 % 550 — — 550 Total issuances $ 3,138 $ 1,688 $ 900 $ 550 (a) Debt issued in response to market volatility concerns related to the COVID-19 pandemic. Refer to Note 1 for additional information on the COVID-19 pandemic. Proceeds will be used to reduce outstanding commercial paper and for general corporate purposes. (b) Debt issuance has a floating interest rate. (c) Debt issued to repay at maturity $450 million first mortgage bonds due June 2020 and for general corporate purposes. (d) Debt issued to repay at maturity $500 million first mortgage bonds due July 2020 and to pay down short-term debt. 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, 2020 Unsecured Debt Duke Energy (Parent) June 2020 2.100 % $ 330 Duke Energy Progress December 2020 2.292 % (a) 700 Progress Energy, Inc January 2021 4.400 % 500 Duke Energy (Parent) March 2021 1.400 % (a) 1,688 First Mortgage Bonds Duke Energy Florida April 2020 4.550 % 250 Duke Energy Carolinas June 2020 4.300 % 450 Duke Energy Indiana July 2020 3.750 % 500 Duke Energy Progress September 2020 1.076 % (a) 300 Other (b) 359 Current maturities of long-term debt $ 5,077 (a) Debt issuance has a floating interest rate. (b) Includes finance lease obligations, amortizing debt and small bullet maturities. AVAILABLE CREDIT FACILITIES Master Credit Facility In March 2020, Duke Energy amended its existing $8 billion Master Credit Facility to extend the termination date to March 2025 . 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. Duke Energy Carolinas and Duke Energy Progress are also required to each maintain $250 million of available capacity under the Master Credit Facility as security to meet obligations under plea agreements reached with the U.S. Department of Justice in 2015 related to violations at North Carolina facilities with ash basins. This requirement expires on May 15, 2020. The table below includes the current borrowing sublimits and available capacity under these credit facilities. March 31, 2020 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 $ 1,500 $ 1,250 $ 800 $ 600 $ 600 $ 600 Reduction to backstop issuances Commercial paper (b) (2,540 ) (1,140 ) (300 ) (275 ) (167 ) (243 ) (150 ) (265 ) Outstanding letters of credit (49 ) (42 ) (4 ) (2 ) — — — (1 ) Tax-exempt bonds (81 ) — — — — — (81 ) — Coal ash set-aside (500 ) — (250 ) (250 ) — — — — Available capacity under the Master Credit Facility $ 4,830 $ 1,468 $ 946 $ 723 $ 633 $ 357 $ 369 $ 334 (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, 2020 (in millions) Facility size Amount drawn Duke Energy (Parent) Three-Year Revolving Credit Facility (a) $ 1,000 $ 1,000 Duke Energy Progress Term Loan Facility 700 700 (a) In March 2020, Duke Energy (Parent) drew down the remaining $500 million .

Goodwill

Goodwill	3 Months Ended
	Mar. 31, 2020
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, 2020 , and December 31, 2019 . 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, 2020 , and December 31, 2019 . 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
	Mar. 31, 2020
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) 2020 2019 Duke Energy Carolinas Corporate governance and shared service expenses (a) $ 134 $ 212 Indemnification coverages (b) 5 5 Joint Dispatch Agreement (JDA) revenue (c) 7 23 JDA expense (c) 24 93 Intercompany natural gas purchases (d) 6 4 Progress Energy Corporate governance and shared service expenses (a) $ 146 $ 176 Indemnification coverages (b) 9 9 JDA revenue (c) 24 93 JDA expense (c) 7 23 Intercompany natural gas purchases (d) 19 19 Duke Energy Progress Corporate governance and shared service expenses (a) $ 75 $ 106 Indemnification coverages (b) 4 4 JDA revenue (c) 24 93 JDA expense (c) 7 23 Intercompany natural gas purchases (d) 19 19 Duke Energy Florida Corporate governance and shared service expenses (a) $ 71 $ 70 Indemnification coverages (b) 5 5 Duke Energy Ohio Corporate governance and shared service expenses (a) $ 84 $ 85 Indemnification coverages (b) 1 1 Duke Energy Indiana Corporate governance and shared service expenses (a) $ 106 $ 97 Indemnification coverages (b) 2 2 Piedmont Corporate governance and shared service expenses (a) $ 34 $ 32 Indemnification coverages (b) 1 1 Intercompany natural gas sales (d) 25 23 Natural gas storage and transportation costs (e) 6 5 (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, 2020 Intercompany income tax receivable $ — $ 114 $ 1 $ 4 $ — $ — $ — Intercompany income tax payable 44 — — — — 6 10 December 31, 2019 Intercompany income tax receivable $ — $ 125 $ 28 $ — $ 9 $ 28 $ 13 Intercompany income tax payable 5 — — 2 — — —

Derivatives and Hedging

Derivatives and Hedging	3 Months Ended
	Mar. 31, 2020
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 income (loss) for the three months ended March 31, 2020 , and 2019 , 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 business 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, 2020 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Cash flow hedges $ 991 $ — $ — $ — $ — $ — Undesignated contracts 2,027 400 1,600 1,050 550 27 Total notional amount (a) $ 3,018 $ 400 $ 1,600 $ 1,050 $ 550 $ 27 December 31, 2019 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Cash flow hedges $ 993 $ — $ — $ — $ — $ — Undesignated contracts 1,277 450 800 250 550 27 Total notional amount (a) $ 2,270 $ 450 $ 800 $ 250 $ 550 $ 27 (a) Duke Energy includes amounts related to consolidated VIEs of $691 million in cash flow hedges as of March 31, 2020 , and $693 million in cash flow hedges as of December 31, 2019 . 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 coal 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. For the Subsidiary Registrants, bulk power electricity and coal 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, 2020 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Electricity (GWh) 6,737 — — — — 977 5,760 — Natural gas (millions of dekatherms) 709 145 158 158 — — 4 402 December 31, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Electricity (GWh) 15,858 — — — — 1,887 13,971 — Natural gas (millions of dekatherms) 704 130 160 160 — — 3 411 U.S. EQUITY SECURITIES RISK In May 2019, Duke Energy Florida entered into a Decommissioning Services Agreement for the accelerated decommissioning of Crystal River Unit 3 with ADP CR3, LLC and ADP SF1, LLC. See Note 3 for additional information on the accelerated decommissioning. Duke Energy Florida executed U.S. equity option collars within the NDTF in May 2019 to preserve the U.S. equity portfolio value in the Duke Energy Florida NDTF in the event the accelerated decommissioning is approved. These option collars were executed as a purchase of a put option and the sale of a call option on certain U.S. equity index funds. The put and call options create a collar to guarantee a minimum and maximum investment value for the Duke Energy Florida NDTF U.S. equity portfolio. The put and call options were entered into at zero-cost, with the price to purchase the puts offset entirely by the funds received to sell the calls. As of March 31, 2020 , the aggregate notional amount of both the put and call options was 305,000 units in U.S. equity security index funds. The options are not designated as hedging instruments. Substantially all of Duke Energy Florida’s NDTF qualifies for regulatory accounting. With regulatory accounting, the mark-to-market gains or losses on the options are deferred as regulatory liabilities or regulatory assets, respectively. The Duke Energy Florida NDTF liquidated the options in April 2020, and received proceeds of approximately $7 million . 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, 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 $ 6 $ — $ — $ — $ — $ — $ 2 $ 3 Noncurrent 4 2 1 1 — 1 — — Total Derivative Assets – Commodity Contracts $ 10 $ 2 $ 1 $ 1 $ — $ 1 $ 2 $ 3 Interest Rate Contracts Not Designated as Hedging Instruments Current $ 3 $ — $ 3 $ 3 $ — $ — $ — $ — Noncurrent 1 — 1 1 — — — — Total Derivative Assets – Interest Rate Contracts $ 4 $ — $ 4 $ 4 $ — $ — $ — $ — Equity Securities Contracts Not Designated as Hedging Instruments Noncurrent (a) 20 — 20 — 20 — — — Total Derivative Assets – Equity Securities Contracts $ 20 $ — $ 20 $ — $ 20 $ — $ — $ — Total Derivative Assets $ 34 $ 2 $ 25 $ 5 $ 20 $ 1 $ 2 $ 3 (a) Equity security contracts are current since they were set to expire in May 2020 but are classified as noncurrent assets on the Condensed Consolidated Balance Sheet because the amount is presented within the NDTF. Derivative Liabilities 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 Commodity Contracts Not Designated as Hedging Instruments Current $ 79 $ 40 $ 31 $ 31 $ — $ — $ — $ 8 Noncurrent 130 11 35 20 — — — 83 Total Derivative Liabilities – Commodity Contracts $ 209 $ 51 $ 66 $ 51 $ — $ — $ — $ 91 Interest Rate Contracts Designated as Hedging Instruments Current $ 69 $ — $ — $ — $ — $ — $ — $ — Noncurrent 54 — — — — — — — Not Designated as Hedging Instruments Current 30 — 29 — 29 1 — — Noncurrent 28 23 — — — 6 — — Total Derivative Liabilities – Interest Rate Contracts $ 181 $ 23 $ 29 $ — $ 29 $ 7 $ — $ — Total Derivative Liabilities $ 390 $ 74 $ 95 $ 51 $ 29 $ 7 $ — $ 91 Derivative Assets December 31, 2019 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 $ 17 $ — $ — $ — $ — $ 3 $ 13 $ 1 Noncurrent 1 — — — — 1 — — Total Derivative Assets – Commodity Contracts $ 18 $ — $ — $ — $ — $ 4 $ 13 $ 1 Interest Rate Contracts Not Designated as Hedging Instruments Current 6 — 6 — 6 — — — Total Derivative Assets – Interest Rate Contracts $ 6 $ — $ 6 $ — $ 6 $ — $ — $ — Equity Securities Contracts Not Designated as Hedging Instruments Current 1 — 1 — 1 — — — Total Derivative Assets – Equity Securities Contracts $ 1 $ — $ 1 $ — $ 1 $ — $ — $ — Total Derivative Assets $ 25 $ — $ 7 $ — $ 7 $ 4 $ 13 $ 1 Derivative Liabilities December 31, 2019 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 $ 67 $ 33 $ 26 $ 26 $ — $ — $ 1 $ 7 Noncurrent 156 10 37 22 — — — 110 Total Derivative Liabilities – Commodity Contracts $ 223 $ 43 $ 63 $ 48 $ — $ — $ 1 $ 117 Interest Rate Contracts Designated as Hedging Instruments Current $ 19 $ — $ — $ — $ — $ — $ — $ — Noncurrent 21 — — — — — — — Not Designated as Hedging Instruments Current 8 6 1 1 — 1 — — Noncurrent 5 — — — — 5 — — Total Derivative Liabilities – Interest Rate Contracts $ 53 $ 6 $ 1 $ 1 $ — $ 6 $ — $ — Equity Securities Contracts Not Designated as Hedging Instruments Current 24 — 24 — 24 — — — Total Derivative Liabilities – Equity Securities Contracts $ 24 $ — $ 24 $ — $ 24 $ — $ — $ — Total Derivative Liabilities $ 300 $ 49 $ 88 $ 49 $ 24 $ 6 $ 1 $ 117 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, 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 $ 9 $ — $ 3 $ 3 $ — $ — $ 2 $ 3 Gross amounts offset — — — — — — — — Net amounts presented in Current Assets: Other $ 9 $ — $ 3 $ 3 $ — $ — $ 2 $ 3 Noncurrent Gross amounts recognized $ 25 $ 2 $ 22 $ 2 $ 20 $ 1 $ — $ — Gross amounts offset (3 ) (2 ) (1 ) (1 ) — — — — Net amounts presented in Other Noncurrent Assets: Other $ 2 $ — $ 1 $ 1 $ — $ 1 $ — $ — Net amounts presented in NDTF $ 20 $ — $ 20 $ — $ 20 $ — $ — $ — Derivative Liabilities 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 Current Gross amounts recognized $ 178 $ 40 $ 60 $ 31 $ 29 $ 1 $ — $ 8 Gross amounts offset — — — — — — — — Net amounts presented in Current Liabilities: Other $ 178 $ 40 $ 60 $ 31 $ 29 $ 1 $ — $ 8 Noncurrent Gross amounts recognized $ 212 $ 34 $ 35 $ 20 $ — $ 6 $ — $ 83 Gross amounts offset (3 ) (2 ) (1 ) (1 ) — — — — Net amounts presented in Other Noncurrent Liabilities: Other $ 209 $ 32 $ 34 $ 19 $ — $ 6 $ — $ 83 Derivative Assets December 31, 2019 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 $ 24 $ — $ 7 $ — $ 7 $ 3 $ 13 $ 1 Gross amounts offset (1 ) — (1 ) — (1 ) — — — Net amounts presented in Current Assets: Other $ 23 $ — $ 6 $ — $ 6 $ 3 $ 13 $ 1 Noncurrent Gross amounts recognized $ 1 $ — $ — $ — $ — $ 1 $ — $ — Gross amounts offset — — — — — — — — Net amounts presented in Other Noncurrent Assets: Other $ 1 $ — $ — $ — $ — $ 1 $ — $ — Derivative Liabilities December 31, 2019 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 $ 118 $ 39 $ 51 $ 27 $ 24 $ 1 $ 1 $ 7 Gross amounts offset (24 ) — (24 ) — (24 ) — — — Net amounts presented in Current Liabilities: Other $ 94 $ 39 $ 27 $ 27 $ — $ 1 $ 1 $ 7 Noncurrent Gross amounts recognized $ 182 $ 10 $ 37 $ 22 $ — $ 5 $ — $ 110 Gross amounts offset — — — — — — — — Net amounts presented in Other Noncurrent Liabilities: Other $ 182 $ 10 $ 37 $ 22 $ — $ 5 $ — $ 110 OBJECTIVE CREDIT CONTINGENT FEATURES Certain derivative contracts contain objective credit contingent features. These features include the requirement to post cash collateral or letters of credit if specific events occur, such as a credit rating downgrade below investment grade. The following tables show information with respect to derivative contracts that are in a net liability position and contain objective credit-risk-related payment provisions. March 31, 2020 Duke Duke Duke Energy Progress Energy (in millions) Energy Carolinas Energy Progress Aggregate fair value of derivatives in a net liability position $ 96 $ 45 $ 51 $ 51 Fair value of collateral already posted — — — — Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered 96 45 51 51 December 31, 2019 Duke Duke Duke Energy Progress Energy (in millions) Energy Carolinas Energy Progress Aggregate fair value of derivatives in a net liability position $ 79 $ 35 $ 44 $ 44 Fair value of collateral already posted — — — — Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered 79 35 44 44 The Duke Energy Registrants have elected to offset cash collateral and fair values of derivatives. For amounts to be netted, the derivative and cash collateral must be executed with the same counterparty under the same master netting arrangement.

Investments in Debt and Equity

Investments in Debt and Equity Securities	3 Months Ended
	Mar. 31, 2020
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 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 an credit loss exists, the unrealized credit loss is included in earnings. There were no material credit losses as of March 31, 2020 , and December 31, 2019 . 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, 2020 December 31, 2019 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 $ — $ — $ 119 $ — $ — $ 101 Equity securities 2,499 170 4,488 3,523 55 5,661 Corporate debt securities 26 16 642 37 1 603 Municipal bonds 10 2 404 13 — 368 U.S. government bonds 70 — 1,212 33 1 1,256 NDTF equity security contracts 20 — 20 — — — Other debt securities 4 3 163 3 — 141 Total NDTF Investments $ 2,629 $ 191 $ 7,048 $ 3,609 $ 57 $ 8,130 Other Investments Cash and cash equivalents $ — $ — $ 78 $ — $ — $ 52 Equity securities 31 1 95 57 — 122 Corporate debt securities — — 89 3 — 67 Municipal bonds 6 1 98 4 — 94 U.S. government bonds 5 — 51 2 — 41 Other debt securities — — 52 — — 56 Total Other Investments $ 42 $ 2 $ 463 $ 66 $ — $ 432 Total Investments $ 2,671 $ 193 $ 7,511 $ 3,675 $ 57 $ 8,562 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, 2020 , and 2019 , were as follows. Three Months Ended (in millions) March 31, 2020 March 31, 2019 FV-NI: Realized gains $ 23 $ 35 Realized losses 65 30 AFS: Realized gains 20 10 Realized losses 6 11 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, 2020 December 31, 2019 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 $ — $ — $ 33 $ — $ — $ 21 Equity securities 1,355 81 2,498 1,914 8 3,154 Corporate debt securities 15 12 392 21 1 361 Municipal bonds 3 1 128 3 — 96 U.S. government bonds 35 — 502 16 1 578 Other debt securities 3 3 159 3 — 137 Total NDTF Investments $ 1,411 $ 97 $ 3,712 $ 1,957 $ 10 $ 4,347 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, 2020 , and 2019 , were as follows. Three Months Ended (in millions) March 31, 2020 March 31, 2019 FV-NI: Realized gains $ 9 $ 23 Realized losses 45 21 AFS: Realized gains 12 9 Realized losses 5 10 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, 2020 December 31, 2019 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 $ — $ — $ 86 $ — $ — $ 80 Equity securities 1,144 89 1,990 1,609 47 2,507 Corporate debt securities 11 4 250 16 — 242 Municipal bonds 7 1 276 10 — 272 U.S. government bonds 35 — 710 17 — 678 NDTF equity security contracts 20 — 20 — — — Other debt securities 1 — 4 — — 4 Total NDTF Investments $ 1,218 $ 94 $ 3,336 $ 1,652 $ 47 $ 3,783 Other Investments Cash and cash equivalents $ — $ — $ 69 $ — $ — $ 49 Municipal bonds 5 — 53 3 — 51 Total Other Investments $ 5 $ — $ 122 $ 3 $ — $ 100 Total Investments $ 1,223 $ 94 $ 3,458 $ 1,655 $ 47 $ 3,883 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, 2020 , and 2019 , were as follows. Three Months Ended (in millions) March 31, 2020 March 31, 2019 FV-NI: Realized gains $ 14 $ 12 Realized losses 20 9 AFS: Realized gains 5 1 Realized losses 1 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, 2020 December 31, 2019 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 $ — $ — $ 51 $ — $ — $ 53 Equity securities 881 79 1,631 1,258 21 2,077 Corporate debt securities 11 4 250 16 — 242 Municipal bonds 7 1 276 10 — 272 U.S. government bonds 34 — 436 16 — 403 Other debt securities 1 — 4 — — 4 Total NDTF Investments $ 934 $ 84 $ 2,648 $ 1,300 $ 21 $ 3,051 Other Investments Cash and cash equivalents $ — $ — $ 2 $ — $ — $ 2 Total Other Investments $ — $ — $ 2 $ — $ — $ 2 Total Investments $ 934 $ 84 $ 2,650 $ 1,300 $ 21 $ 3,053 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, 2020 , and 2019 , were as follows. Three Months Ended (in millions) March 31, 2020 March 31, 2019 FV-NI: Realized gains $ 14 $ 10 Realized losses 20 8 AFS: Realized gains 5 1 Realized losses 1 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, 2020 December 31, 2019 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 $ — $ — $ 27 Equity securities 263 10 359 351 26 430 U.S. government bonds 1 — 274 1 — 275 NDTF equity security contracts 20 — 20 — — — Total NDTF Investments (a) $ 284 $ 10 $ 688 $ 352 $ 26 $ 732 Other Investments Cash and cash equivalents $ — $ — $ 3 $ — $ — $ 4 Municipal bonds 5 — 53 3 — 51 Total Other Investments $ 5 $ — $ 56 $ 3 $ — $ 55 Total Investments $ 289 $ 10 $ 744 $ 355 $ 26 $ 787 (a) During the three months ended March 31, 2020 , Duke Energy Florida continued to receive 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, 2020 , and 2019 , 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, 2020 December 31, 2019 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 Equity securities $ 26 $ 1 $ 63 $ 43 $ — $ 81 Corporate debt securities — — 4 — — 6 Municipal bonds 1 1 36 1 — 36 U.S. government bonds — — 3 — — 2 Total Investments $ 27 $ 2 $ 106 $ 44 $ — $ 125 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, 2020 , and 2019 , were immaterial. DEBT SECURITY MATURITIES The table below summarizes the maturity date for debt securities. March 31, 2020 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Indiana Due in one year or less $ 333 $ 25 $ 302 $ 26 $ 276 $ 3 Due after one through five years 538 234 236 227 9 17 Due after five through 10 years 465 188 214 207 7 7 Due after 10 years 1,375 734 541 506 35 16 Total $ 2,711 $ 1,181 $ 1,293 $ 966 $ 327 $ 43

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2020
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. 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 12 in Duke Energy's Annual Report on Form 10-K for the year ended December 31, 2019, 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, 2020 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not Categorized NDTF equity securities $ 4,488 $ 4,440 $ — $ — $ 48 NDTF debt securities 2,540 767 1,773 — — Other equity securities 95 95 — — — Other debt securities 368 126 242 — — NDTF equity security contracts 20 — 20 — — Derivative assets 34 3 28 3 — Total assets 7,545 5,431 2,063 3 48 Derivative liabilities (390 ) (49 ) (250 ) (91 ) — Net assets (liabilities) $ 7,155 $ 5,382 $ 1,813 $ (88 ) $ 48 December 31, 2019 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not Categorized NDTF equity securities $ 5,684 $ 5,633 $ — $ — $ 51 NDTF debt securities 2,469 826 1,643 — — Other equity securities 122 122 — — — Other debt securities 310 91 219 — — Derivative assets 25 3 7 15 — Total assets 8,610 6,675 1,869 15 51 NDTF equity security contracts (23 ) — (23 ) — — Derivative liabilities (277 ) (15 ) (145 ) (117 ) — Net assets (liabilities) $ 8,310 $ 6,660 $ 1,701 $ (102 ) $ 51 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) 2020 2019 Balance at beginning of period $ (102 ) $ (113 ) Purchases, sales, issuances and settlements: Settlements (9 ) (12 ) Total gains included on the Condensed Consolidated Balance Sheet 23 10 Balance at end of period $ (88 ) $ (115 ) 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, 2020 (in millions) Total Fair Value Level 1 Level 2 Not Categorized NDTF equity securities $ 2,498 $ 2,450 $ — $ 48 NDTF debt securities 1,214 182 1,032 — Derivative assets 2 — 2 — Total assets 3,714 2,632 1,034 48 Derivative liabilities (74 ) — (74 ) — Net assets $ 3,640 $ 2,632 $ 960 $ 48 December 31, 2019 (in millions) Total Fair Value Level 1 Level 2 Not Categorized NDTF equity securities $ 3,154 $ 3,103 $ — $ 51 NDTF debt securities 1,193 227 966 — Total assets 4,347 3,330 966 51 Derivative liabilities (49 ) — (49 ) — Net assets $ 4,298 $ 3,330 $ 917 $ 51 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, 2020 December 31, 2019 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 NDTF equity securities $ 1,990 $ 1,990 $ — $ 2,530 $ 2,530 $ — NDTF debt securities 1,326 585 741 1,276 599 677 Other debt securities 122 69 53 100 49 51 NDTF equity security contracts 20 — 20 — — — Derivative assets 25 — 25 7 — 7 Total assets 3,483 2,644 839 3,913 3,178 735 NDTF equity security contracts — — — (23 ) — (23 ) Derivative liabilities (95 ) — (95 ) (65 ) — (65 ) Net assets $ 3,388 $ 2,644 $ 744 $ 3,825 $ 3,178 $ 647 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, 2020 December 31, 2019 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 NDTF equity securities $ 1,631 $ 1,631 $ — $ 2,077 $ 2,077 $ — NDTF debt securities 1,017 276 741 974 297 677 Other debt securities 2 2 — 2 2 — Derivative assets 5 — 5 — — — Total assets 2,655 1,909 746 3,053 2,376 677 Derivative liabilities (51 ) — (51 ) (49 ) — (49 ) Net assets $ 2,604 $ 1,909 $ 695 $ 3,004 $ 2,376 $ 628 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, 2020 December 31, 2019 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 NDTF equity securities $ 359 $ 359 $ — $ 453 $ 453 $ — NDTF debt securities 309 309 — 302 302 — Other debt securities 56 3 53 55 4 51 NDTF equity security contracts 20 — 20 — — — Derivative assets — — — 7 — 7 Total assets 744 671 73 817 759 58 NDTF equity security contracts — — — (23 ) — (23 ) Derivative liabilities (29 ) — (29 ) (1 ) — (1 ) Net assets $ 715 $ 671 $ 44 $ 793 $ 759 $ 34 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, 2020 , and December 31, 2019 . 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, 2020 December 31, 2019 (in millions) Total Fair Value Level 1 Level 2 Level 3 Total Fair Value Level 1 Level 2 Level 3 Other equity securities $ 63 $ 63 $ — $ — $ 81 $ 81 $ — $ — Other debt securities 43 — 43 — 44 — 44 — Derivative assets 2 — — 2 13 2 — 11 Total assets $ 108 $ 63 $ 43 $ 2 $ 138 $ 83 $ 44 $ 11 Derivative liabilities — — — — (1 ) (1 ) — — Net assets $ 108 $ 63 $ 43 $ 2 $ 137 $ 82 $ 44 $ 11 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) 2020 2019 Balance at beginning of period $ 11 $ 22 Purchases, sales, issuances and settlements: Settlements (6 ) (10 ) Total losses included on the Condensed Consolidated Balance Sheet (3 ) (7 ) Balance at end of period $ 2 $ 5 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, 2020 December 31, 2019 (in millions) Total Fair Value Level 1 Level 3 Total Fair Value Level 1 Level 3 Derivative assets $ 3 $ 3 $ — $ 1 $ 1 $ — Derivative liabilities (91 ) — (91 ) (117 ) — (117 ) Net (liabilities) assets $ (88 ) $ 3 $ (91 ) $ (116 ) $ 1 $ (117 ) 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) 2020 2019 Balance at beginning of period $ (117 ) $ (141 ) Total gains and settlements 26 20 Balance at end of period $ (91 ) $ (121 ) QUANTITATIVE INFORMATION ABOUT UNOBSERVABLE INPUTS The following tables include quantitative information about the Duke Energy Registrants' derivatives classified as Level 3. March 31, 2020 Weighted Fair Value Average Investment Type (in millions) Valuation Technique Unobservable Input Range Range Duke Energy Ohio FTRs $ 1 RTO auction pricing FTR price – per MWh $ 0.04 - $ 3.29 $ 1.03 Duke Energy Indiana FTRs 2 RTO auction pricing FTR price – per MWh (0.37 ) - 6.06 0.54 Piedmont Natural gas contracts (91 ) Discounted cash flow Forward natural gas curves – price per MMBtu 1.64 - 2.41 1.94 Duke Energy Total Level 3 derivatives $ (88 ) December 31, 2019 Weighted Fair Value Average Investment Type (in millions) Valuation Technique Unobservable Input Range Range Duke Energy Ohio FTRs $ 4 RTO auction pricing FTR price – per MWh $ 0.59 - $ 3.47 $ 2.07 Duke Energy Indiana FTRs 11 RTO auction pricing FTR price – per MWh (0.66 ) - 9.24 1.15 Piedmont Natural gas contracts (117 ) Discounted cash flow Forward natural gas curves – price per MMBtu 1.59 - 2.46 1.91 Duke Energy Total Level 3 derivatives $ (102 ) 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, 2020 December 31, 2019 (in millions) Book Value Fair Value Book Value Fair Value Duke Energy (a) $ 61,388 $ 65,644 $ 58,126 $ 63,062 Duke Energy Carolinas 12,807 14,312 11,900 13,516 Progress Energy 19,355 21,802 19,634 22,291 Duke Energy Progress 9,059 9,798 9,058 9,934 Duke Energy Florida 7,706 8,831 7,987 9,131 Duke Energy Ohio 2,620 2,904 2,619 2,964 Duke Energy Indiana 4,603 5,433 4,057 4,800 Piedmont 2,385 2,551 2,384 2,642 (a) Book value of long-term debt includes $1.4 billion at March 31, 2020 , and $1.5 billion at December 31, 2019 , 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, 2020 , and December 31, 2019 , 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
	Mar. 31, 2020
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, 2020 , and the year ended December 31, 2019 , 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. The sole source of funds to satisfy the related debt obligations is cash collections from the receivables. Amounts borrowed under the credit facilities are reflected on the Condensed Consolidated Balance Sheets as 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. Due to the COVID-19 pandemic, as described in Note 1, the Duke Energy Registrants suspended customer disconnections for nonpayment. The impact of COVID-19 and the Duke Energy Registrant’s related response on customers’ ability to pay for service is uncertain, and it is reasonably possible eventual write-offs of customer receivables may increase over current estimates. See Note 3 for information about COVID-19 filings with state utility commissions. 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. 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. Due to the COVID-19 pandemic, as described in Note 1, the Duke Energy Registrants suspended customer disconnections for nonpayment. The impact of COVID-19 and the Duke Energy Registrant’s related response on customers’ ability to pay for service is uncertain, and it is reasonably possible eventual write-offs of customer receivables may increase over current estimates. See Note 3 for information about COVID-19 filings with state utility commissions. 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 2021 Credit facility amount $ 350 $ 475 $ 375 $ 250 Amounts borrowed at March 31, 2020 350 475 325 250 Amounts borrowed at December 31, 2019 350 474 325 250 Restricted Receivables at March 31, 2020 467 616 410 331 Restricted Receivables at December 31, 2019 522 642 489 336 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, 2020 December 31, 2019 Receivables of VIEs $ 4 $ 5 Regulatory Assets: Current 53 52 Current Assets: Other 13 39 Other Noncurrent Assets: Regulatory assets 980 989 Current Liabilities: Other 2 10 Current maturities of long-term debt 54 54 Long-Term Debt 1,028 1,057 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, 2020 December 31, 2019 Current Assets: Other $ 287 $ 203 Property, Plant and Equipment: Cost 6,106 5,747 Accumulated depreciation and amortization (1,094 ) (1,041 ) Other Noncurrent Assets: Other 82 106 Current maturities of long-term debt 162 162 Long-Term Debt 1,538 1,541 Other Noncurrent Liabilities: AROs 129 127 Other Noncurrent Liabilities: Other 258 228 NON-CONSOLIDATED VIEs The following tables summarize the impact of non-consolidated VIEs on the Condensed Consolidated Balance Sheets. March 31, 2020 Duke Energy Duke Duke Pipeline Commercial Other Energy Energy (in millions) Investments Renewables VIEs Total Ohio Indiana Receivables from affiliated companies $ — $ (1 ) $ — $ (1 ) $ 39 $ 48 Investments in equity method unconsolidated affiliates 1,243 371 — 1,614 — — Total assets $ 1,243 $ 370 $ — $ 1,613 $ 39 $ 48 Taxes accrued (1 ) — — (1 ) — — Other current liabilities — — 3 3 — — Deferred income taxes 69 — — 69 — — Other noncurrent liabilities 105 — 11 116 — — Total liabilities $ 173 $ — $ 14 $ 187 $ — $ — Net assets (liabilities) $ 1,070 $ 370 $ (14 ) $ 1,426 $ 39 $ 48 December 31, 2019 Duke Energy Duke Duke Pipeline Commercial Other Energy Energy (in millions) Investments Renewables VIEs Total Ohio Indiana Receivables from affiliated companies $ — $ (1 ) $ — $ (1 ) $ 64 $ 77 Investments in equity method unconsolidated affiliates 1,179 300 — 1,479 — — Total assets $ 1,179 $ 299 $ — $ 1,478 $ 64 $ 77 Taxes accrued (1 ) — — (1 ) — — Other current liabilities — — 4 4 — — Deferred income taxes 59 — — 59 — — Other noncurrent liabilities — — 11 11 — — Total liabilities $ 58 $ — $ 15 $ 73 $ — $ — Net assets (liabilities) $ 1,121 $ 299 $ (15 ) $ 1,405 $ 64 $ 77 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 the PPA with OVEC, which is discussed below, and various guarantees, including Duke Energy's guarantee agreement to support its share of the ACP revolving credit facility. Duke Energy's maximum exposure to loss under the terms of the guarantee is $845 million , which represents 47% of the outstanding borrowings under the credit facility as of March 31, 2020 . For more information on various guarantees, refer to Note 4 . Pipeline Investments Duke Energy has investments in various joint ventures with pipeline projects currently under construction. 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. The table below presents Duke Energy's ownership interest and investment balances in these joint ventures. VIE Investment Amount (in millions) Ownership March 31, December 31, Entity Name Interest 2020 2019 ACP (a) 47 % $ 1,243 $ 1,179 Constitution (b) 24 % — — Total $ 1,243 $ 1,179 (a) Duke Energy evaluated this investment for impairment as of March 31, 2020 , and December 31, 2019 , and determined that fair value approximated carrying value and therefore no impairment was necessary. (b) During the year ended December 31, 2019, Duke Energy recorded an OTTI related to Constitution. This charge resulted in the full write-down of Duke Energy's investment in Constitution. 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. In 2019, Duke Energy acquired a majority ownership in a portfolio of distributed fuel cell projects from Bloom Energy Corporation. Duke Energy is not the primary beneficiary of the assets within the portfolio and does not consolidate the assets in the portfolio. 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. On March 31, 2018, FirstEnergy Solutions Corp (FES), a subsidiary of FirstEnergy Corp. and an ICPA counterparty with a power participation ratio of 4.85% , filed for Chapter 11 bankruptcy, which could increase costs allocated to the counterparties. On July 31, 2018, the bankruptcy court rejected the FES ICPA, which means OVEC is an unsecured creditor in the FES bankruptcy proceeding. In addition, certain proposed environmental rulemaking could result in future increased OVEC cost allocations. 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, 2020 December 31, 2019 March 31, 2020 December 31, 2019 Receivables sold $ 234 $ 253 $ 274 $ 307 Less: Retained interests 39 64 48 77 Net receivables sold $ 195 $ 189 $ 226 $ 230 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) 2020 2019 2020 2019 Sales Receivables sold $ 537 $ 575 $ 647 $ 734 Loss recognized on sale 4 4 4 5 Cash flows Cash proceeds from receivables sold $ 559 $ 597 $ 672 $ 758 Return received on retained interests 2 2 2 3 Cash flows from sales of receivables are reflected within Cash Flows From Operating Activities on Duke Energy Ohio’s and Duke Energy Indiana’s Condensed Consolidated Statements of Cash Flows.

Revenue

Revenue	3 Months Ended
	Mar. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue	REVENUE Duke 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) 2020 2021 2022 2023 2024 Thereafter Total Progress Energy $ 84 $ 92 $ 87 $ 44 $ 45 $ 58 $ 410 Duke Energy Progress 6 8 8 8 8 — 38 Duke Energy Florida 78 84 79 36 37 58 372 Duke Energy Indiana 8 5 — — — — 13 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 revenues 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) 2020 2021 2022 2023 2024 Thereafter Total Piedmont $ 51 $ 65 $ 64 $ 61 $ 58 $ 376 $ 675 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, 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, 2019 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 $ 2,370 $ 760 $ 1,114 $ 536 $ 578 $ 189 $ 306 $ — General 1,427 496 632 306 326 103 197 — Industrial 711 266 222 161 61 33 190 — Wholesale 541 119 353 315 38 14 54 — Other revenues 172 78 172 125 47 16 17 — Total Electric Utilities and Infrastructure revenue from contracts with customers $ 5,221 $ 1,719 $ 2,493 $ 1,443 $ 1,050 $ 355 $ 764 $ — Gas Utilities and Infrastructure Residential $ 414 $ — $ — $ — $ — $ 112 $ — $ 302 Commercial 206 — — — — 49 — 157 Industrial 48 — — — — 7 — 42 Power Generation — — — — — — — 13 Other revenues 63 — — — — 8 — 56 Total Gas Utilities and Infrastructure revenue from contracts with customers $ 731 $ — $ — $ — $ — $ 176 $ — $ 570 Commercial Renewables Revenue from contracts with customers $ 42 $ — $ — $ — $ — $ — $ — $ — Other Revenue from contracts with customers $ 4 $ — $ — $ — $ — $ — $ — $ — Total revenue from contracts with customers $ 5,998 $ 1,719 $ 2,493 $ 1,443 $ 1,050 $ 531 $ 764 $ 570 Other revenue sources (a) $ 165 $ 25 $ 79 $ 41 $ 36 $ — $ 4 $ 9 Total revenues $ 6,163 $ 1,744 $ 2,572 $ 1,484 $ 1,086 $ 531 $ 768 $ 579 (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. 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 following table presents the reserve for credit losses for trade and other receivables based on adoption of the new standard. 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 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 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 annually for trade and other receivables. Due to the COVID-19 pandemic, as described in Note 1 , the Duke Energy Registrants suspended customer disconnections for nonpayment. The specific actions taken by each Duke Energy Registrant are described in Note 3 . The impact of COVID-19 and Duke Energy’s related response on customers’ ability to pay for service is uncertain, and it is reasonably possible eventual write-offs of customer receivables may increase over current estimates. The aging of trade receivables is presented in the table below. Duke Energy considers receivables greater than 30 days outstanding past due. 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 Unbilled Receivables $ 716 $ 285 $ 195 $ 85 $ 110 $ 1 $ 16 $ 32 0-30 days 1,584 448 585 321 262 45 24 134 30-60 days 216 69 67 44 23 9 1 18 60-90 days 65 18 20 14 6 2 1 5 90+ days 145 19 57 32 25 32 11 11 Trade and Other Receivables $ 2,726 $ 839 $ 924 $ 496 $ 426 $ 89 $ 53 $ 200 UNBILLED REVENUE Unbilled revenues are recognized by applying customer billing rates to the estimated volumes of energy or natural gas delivered but not yet billed. Unbilled revenues can vary significantly from period to period as a result of seasonality, weather, customer usage patterns, customer mix, average price in effect for customer classes, timing of rendering customer bills and meter reading schedules and the impact of weather normalization or margin decoupling mechanisms. Unbilled revenues are included within Receivables and Receivables of VIEs on the Condensed Consolidated Balance Sheets as shown in the following table. (in millions) March 31, 2020 December 31, 2019 Duke Energy $ 716 $ 843 Duke Energy Carolinas 285 298 Progress Energy 195 217 Duke Energy Progress 85 122 Duke Energy Florida 110 95 Duke Energy Ohio 1 1 Duke Energy Indiana 16 16 Piedmont 32 78 Additionally, 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 shown in the table below. (in millions) March 31, 2020 December 31, 2019 Duke Energy Ohio $ 61 $ 82 Duke Energy Indiana 94 115

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2020
Equity [Abstract]
Stockholders' Equity	STOCKHOLDERS' EQUITY 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, 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, 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 stock options and 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) 2020 2019 Income from continuing operations available to Duke Energy common stockholders excluding impact of participating securities and including accumulated preferred stock dividends adjustment $ 911 $ 898 Weighted average common shares outstanding – basic 734 727 Equity forwards 2 — Weighted average common shares outstanding – diluted 736 727 EPS from continuing operations available to Duke Energy common stockholders Basic and diluted $ 1.24 $ 1.24 Potentially dilutive items excluded from the calculation (a) 2 2 Dividends declared per common share $ 0.945 $ 0.9275 Dividends declared on Series A preferred stock per depositary share (b) $ 0.359 $ — Dividends declared on Series B preferred stock per share (c) $ 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. Common Stock In November 2019, Duke Energy filed a prospectus supplement and executed an Equity Distribution Agreement (EDA) under which it may sell up to $1.5 billion of its common stock through an at-the-market (ATM) offering program, including an equity forward sales component. Under the terms of the EDA, Duke Energy may issue and sell shares of common stock through September 2022. In March 2020, Duke Energy marketed approximately 940,000 shares of common stock through an equity forward transaction under the ATM with an initial forward price of $89.76 per share. Separately, in November 2019, Duke Energy marketed an equity offering of 28.75 million shares of common stock through an Underwriting Agreement. In connection with the offering, Duke Energy entered into an equity forward sales agreement with an initial forward price of $85.99 per share. The equity forward sales agreements require Duke Energy to either physically settle the transaction by issuing shares in exchange for net proceeds at the then-applicable forward sale price specified by the agreement, or net settle in whole or in part through the delivery or receipt of cash or shares. The settlement alternatives are at Duke Energy's election. Settlement of the forward sales agreements are expected to occur on or prior to December 31, 2020. Until settlement of the equity forwards, EPS dilution resulting from the agreements, if any, will be determined under the treasury stock method.

Employee Benefit Plans

Employee Benefit Plans	3 Months Ended
	Mar. 31, 2020
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, 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 ) Three Months Ended March 31, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Service cost $ 37 $ 12 $ 11 $ 6 $ 4 $ 1 $ 2 $ 1 Interest cost on projected benefit obligation 83 20 26 12 14 5 6 3 Expected return on plan assets (143 ) (38 ) (44 ) (23 ) (22 ) (8 ) (11 ) (5 ) Amortization of actuarial loss 24 6 9 3 6 1 2 2 Amortization of prior service credit (8 ) (2 ) (1 ) — — — — (3 ) Net periodic pension costs $ (7 ) $ (2 ) $ 1 $ (2 ) $ 2 $ (1 ) $ (1 ) $ (2 ) NON-QUALIFIED PENSION PLANS Net periodic pension costs for non-qualified pension plans were not material for the three months ended March 31, 2020, and 2019. OTHER POST-RETIREMENT BENEFIT PLANS Net periodic costs for other post-retirement benefit plans were not material for the three months ended March 31, 2020, and 2019.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2020
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, 2020 2019 Duke Energy 13.3 % 9.6 % Duke Energy Carolinas 16.1 % 17.7 % Progress Energy 17.5 % 17.3 % Duke Energy Progress 17.1 % 17.8 % Duke Energy Florida 20.0 % 19.3 % Duke Energy Ohio 17.7 % 16.9 % Duke Energy Indiana 20.8 % 24.1 % Piedmont 10.1 % 21.8 % The increase in the ETR for Duke Energy for the three months ended March 31, 2020 , was primarily due to an adjustment related to the income tax recognition for equity method investments recorded in the first quarter of 2019, partially offset by an increase in the amortization of excess deferred taxes. The equity method investment adjustment was immaterial and relates to prior years. The decrease in the ETR for Duke Energy Carolinas for the three months ended March 31, 2020 , was primarily due to an increase in the amortization of excess deferred taxes. The decrease in the ETR for Duke Energy Indiana for the three months ended March 31, 2020, was primarily due to an increase in the amortization of excess deferred taxes. The decrease in the ETR for Piedmont for the three months ended March 31, 2020, was primarily due to an increase in the amortization of excess deferred taxes. OTHER TAX MATTERS On March 27, 2020, the CARES Act was enacted. The CARES Act is an emergency economic stimulus package in response to the COVID-19 pandemic. Among other provisions, the CARES Act accelerates the remaining AMT credit refund allowances resulting in taxpayers being able to immediately claim a refund in full for any AMT credit carryforwards. As a result, the remaining AMT credit carryforwards have been reclassified to a current receivable included in Other within Current Assets on the Condensed Consolidated Balance Sheets as of March 31, 2020. The total income tax receivable related to AMT credit carryforwards is approximately $572 million . The other provisions within the CARES Act do not materially impact Duke Energy's income tax accounting. See Note 1 for information on COVID-19.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS For information on subsequent events related to regulatory matters, commitments and contingencies and derivatives and hedging, see Notes 3, 4 and 8.

Organization and Basis of Pre_2

Organization and Basis of Presentation (Policy)	3 Months Ended
	Mar. 31, 2020
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, 2019 . 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. COVID-19 The COVID-19 pandemic is having a significant impact on global health and economic environments. In March 2020, the World Health Organization (WHO) declared COVID-19 a global pandemic, and President Trump proclaimed that the COVID-19 outbreak in the United States constitutes a national emergency. The COVID-19 pandemic has not had a material financial impact on the Duke Energy Registrants as of March 31, 2020; however, the extent to which the COVID-19 pandemic will impact the Duke Energy Registrants during 2020 and beyond is uncertain at this time. The Duke Energy Registrants are monitoring developments closely. See Notes 3 , 5 , 11 , 12 and 15 for information on COVID-19 and steps taken to mitigate the impacts to our business and customers. 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, 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. Duke Energy has received $103 million for the sale of noncontrolling interests to tax equity members for the three months ended March 31, 2020 . Duke Energy allocated approximately $49 million and $7 million of losses to noncontrolling tax equity members utilizing the HLBV method for the three months ended March 31, 2020 , and March 31, 2019 , respectively. 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 .
Cash, Cash Equivalents, and Restricted Cash	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 Note 11
New Accounting Standards	NEW ACCOUNTING STANDARDS The following new accounting standard was adopted by the Duke Energy Registrants in 2020 . Current Expected Credit Losses. In June 2016, the 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, 2020 . 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.
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	For the Subsidiary Registrants, bulk power electricity and coal 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. 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.
Investments	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 an credit loss exists, the unrealized credit loss is included in earnings.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.
Revenue from Contract with Customer	UNBILLED REVENUE Unbilled revenues are recognized by applying customer billing rates to the estimated volumes of energy or natural gas delivered but not yet billed. Unbilled revenues can vary significantly from period to period as a result of seasonality, weather, customer usage patterns, customer mix, average price in effect for customer classes, timing of rendering customer bills and meter reading schedules and the impact of weather normalization or margin decoupling mechanisms.
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, 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, 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 stock options and 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
	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
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, 2020 December 31, 2019 Duke Duke Duke Progress Energy Duke Progress Energy Energy Energy Florida Energy Energy Florida Current Assets Cash and cash equivalents $ 1,450 $ 52 $ 12 $ 311 $ 48 $ 17 Other 185 13 13 222 39 39 Other Noncurrent Assets Other 63 60 — 40 39 — Total cash, cash equivalents and restricted cash $ 1,698 $ 125 $ 25 $ 573 $ 126 $ 56
Schedule of Utility Inventory	The components of inventory are presented in the tables below. 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 Materials and supplies $ 2,280 $ 759 $ 1,018 $ 678 $ 340 $ 83 $ 319 $ 5 Coal 742 268 246 167 79 10 218 — Natural gas, oil and other fuel 302 40 199 111 89 28 1 34 Total inventory $ 3,324 $ 1,067 $ 1,463 $ 956 $ 508 $ 121 $ 538 $ 39 December 31, 2019 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 $ 2,297 $ 768 $ 1,038 $ 686 $ 351 $ 79 $ 318 $ 5 Coal 586 187 186 138 48 15 198 — Natural gas, oil and other fuel 349 41 199 110 90 41 1 67 Total inventory $ 3,232 $ 996 $ 1,423 $ 934 $ 489 $ 135 $ 517 $ 72
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
	Mar. 31, 2020
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, 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) (a) $ 705 $ 249 $ 57 $ 1,011 $ (112 ) $ — $ 899 Add: Noncontrolling interests (b) (48 ) Add: Preferred stock dividend 39 Net income $ 890 Segment assets $ 134,838 $ 14,098 $ 6,184 $ 155,120 $ 4,964 $ (12 ) $ 160,072 Three Months Ended March 31, 2019 Electric Gas Total Utilities and Utilities and Commercial Reportable (in millions) Infrastructure Infrastructure Renewables Segments Other Eliminations Total Unaffiliated revenues $ 5,321 $ 732 $ 106 $ 6,159 $ 4 $ — $ 6,163 Intersegment revenues 8 24 — 32 17 (49 ) — Total revenues $ 5,329 $ 756 $ 106 $ 6,191 $ 21 $ (49 ) $ 6,163 Segment income (loss) $ 750 $ 226 $ 13 $ 989 $ (89 ) $ — $ 900 Add: Noncontrolling interests (b) (7 ) Net income $ 893 (a) Other includes a $98 million reversal, included in Operations, maintenance and other on the Condensed Consolidated Statements of Operations, of 2018 severance costs due to the partial settlement of the Duke Energy Carolina's 2019 North Carolina rate case. See Note 3 for additional information. (b) Includes the allocation of losses to noncontrolling tax equity members. See Note 1 for additional information.
Duke Energy Ohio
Segment Reporting Information [Line Items]
Business Segment Data	Three Months Ended March 31, 2020 Electric Gas Total Utilities and Utilities and Reportable (in millions) Infrastructure Infrastructure Segments Other Eliminations Total Total revenues $ 346 $ 152 $ 498 $ — $ — $ 498 Segment income/Net (loss) income $ 30 $ 36 $ 66 $ (1 ) $ — $ 65 Segment assets $ 6,238 $ 3,135 $ 9,373 $ 26 $ (2 ) $ 9,397 Three Months Ended March 31, 2019 Electric Gas Total Utilities and Utilities and Reportable (in millions) Infrastructure Infrastructure Segments Other Total Total revenues $ 355 $ 176 $ 531 $ — $ 531 Segment income/Net (loss) income $ 36 $ 35 $ 71 $ (2 ) $ 69

Regulatory Matters (Tables)

Regulatory Matters (Tables)	3 Months Ended
	Mar. 31, 2020
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 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, 2020 , and exclude capitalized asset retirement costs. Remaining Net Capacity Book Value (in MW) (in millions) Duke Energy Carolinas Allen Steam Station Units 1-3 (a) 585 $ 149 Duke Energy Indiana Gallagher Units 2 and 4 (b) 280 118 Gibson Units 1-5 (c) 3,132 1,708 Cayuga Units 1-2 (c) 1,005 964 Total Duke Energy 5,002 $ 2,939 (a) Duke Energy Carolinas will retire Allen Steam Station Units 1 through 3 by December 31, 2024, as part of the resolution of a lawsuit involving alleged New Source Review violations. (b) 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. (c) 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, includes proposed depreciation rates reflecting retirement dates from 2026 to 2038.

Commitments and Contingencies (

Commitments and Contingencies (Table)	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Schedule of Reserves	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, 2020 December 31, 2019 Reserves for Legal Matters Duke Energy $ 61 $ 62 Duke Energy Carolinas 3 2 Progress Energy 52 55 Duke Energy Progress 9 12 Duke Energy Florida 23 22 Piedmont 1 1 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. 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 Balance at beginning of period $ 58 $ 11 $ 16 $ 4 $ 9 $ 19 $ 4 $ 8 Provisions/adjustments 3 — — 1 — 1 1 — Cash reductions (3 ) (1 ) (1 ) — — (1 ) — — Balance at end of period $ 58 $ 10 $ 15 $ 5 $ 9 $ 19 $ 5 $ 8
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 $ 58 Duke Energy Carolinas 11 Duke Energy Ohio 41 Piedmont 2

Debt and Credit Facilities (Tab

Debt and Credit Facilities (Tables)	3 Months Ended
	Mar. 31, 2020
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	The following table summarizes significant debt issuances (in millions). Three Months Ended March 31, 2020 Duke Duke Duke Maturity Interest Duke Energy Energy Energy Issuance Date Date Rate Energy (Parent) Carolinas Indiana Unsecured Debt March 2020 (a) March 2021 1.400 % (b) $ 1,688 $ 1,688 $ — $ — First Mortgage Bonds January 2020 (c) February 2030 2.450 % 500 — 500 — January 2020 (c) August 2049 3.200 % 400 — 400 — March 2020 (d) April 2050 2.750 % 550 — — 550 Total issuances $ 3,138 $ 1,688 $ 900 $ 550 (a) Debt issued in response to market volatility concerns related to the COVID-19 pandemic. Refer to Note 1 for additional information on the COVID-19 pandemic. Proceeds will be used to reduce outstanding commercial paper and for general corporate purposes. (b) Debt issuance has a floating interest rate. (c) Debt issued to repay at maturity $450 million first mortgage bonds due June 2020 and for general corporate purposes. (d) Debt issued to repay at maturity $500 million first mortgage bonds due July 2020 and to pay down short-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, 2020 Unsecured Debt Duke Energy (Parent) June 2020 2.100 % $ 330 Duke Energy Progress December 2020 2.292 % (a) 700 Progress Energy, Inc January 2021 4.400 % 500 Duke Energy (Parent) March 2021 1.400 % (a) 1,688 First Mortgage Bonds Duke Energy Florida April 2020 4.550 % 250 Duke Energy Carolinas June 2020 4.300 % 450 Duke Energy Indiana July 2020 3.750 % 500 Duke Energy Progress September 2020 1.076 % (a) 300 Other (b) 359 Current maturities of long-term debt $ 5,077 (a) Debt issuance has a floating interest rate. (b) Includes finance lease obligations, amortizing debt 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, 2020 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 $ 1,500 $ 1,250 $ 800 $ 600 $ 600 $ 600 Reduction to backstop issuances Commercial paper (b) (2,540 ) (1,140 ) (300 ) (275 ) (167 ) (243 ) (150 ) (265 ) Outstanding letters of credit (49 ) (42 ) (4 ) (2 ) — — — (1 ) Tax-exempt bonds (81 ) — — — — — (81 ) — Coal ash set-aside (500 ) — (250 ) (250 ) — — — — Available capacity under the Master Credit Facility $ 4,830 $ 1,468 $ 946 $ 723 $ 633 $ 357 $ 369 $ 334 (a) Represents the sublimit of each borrower. (b) Duke Energy issued $625 million Other Credit Facilities March 31, 2020 (in millions) Facility size Amount drawn Duke Energy (Parent) Three-Year Revolving Credit Facility (a) $ 1,000 $ 1,000 Duke Energy Progress Term Loan Facility 700 700 (a) In March 2020, Duke Energy (Parent) drew down the remaining $500 million .

Goodwill (Tables)

Goodwill (Tables)	3 Months Ended
	Mar. 31, 2020
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, 2020 , and December 31, 2019 . 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
	Mar. 31, 2020
Related Party Transactions [Abstract]
Schedule of Related Party Transactions, Other Revenue and Expense	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, 2020 Intercompany income tax receivable $ — $ 114 $ 1 $ 4 $ — $ — $ — Intercompany income tax payable 44 — — — — 6 10 December 31, 2019 Intercompany income tax receivable $ — $ 125 $ 28 $ — $ 9 $ 28 $ 13 Intercompany income tax payable 5 — — 2 — — — Three Months Ended March 31, (in millions) 2020 2019 Duke Energy Carolinas Corporate governance and shared service expenses (a) $ 134 $ 212 Indemnification coverages (b) 5 5 Joint Dispatch Agreement (JDA) revenue (c) 7 23 JDA expense (c) 24 93 Intercompany natural gas purchases (d) 6 4 Progress Energy Corporate governance and shared service expenses (a) $ 146 $ 176 Indemnification coverages (b) 9 9 JDA revenue (c) 24 93 JDA expense (c) 7 23 Intercompany natural gas purchases (d) 19 19 Duke Energy Progress Corporate governance and shared service expenses (a) $ 75 $ 106 Indemnification coverages (b) 4 4 JDA revenue (c) 24 93 JDA expense (c) 7 23 Intercompany natural gas purchases (d) 19 19 Duke Energy Florida Corporate governance and shared service expenses (a) $ 71 $ 70 Indemnification coverages (b) 5 5 Duke Energy Ohio Corporate governance and shared service expenses (a) $ 84 $ 85 Indemnification coverages (b) 1 1 Duke Energy Indiana Corporate governance and shared service expenses (a) $ 106 $ 97 Indemnification coverages (b) 2 2 Piedmont Corporate governance and shared service expenses (a) $ 34 $ 32 Indemnification coverages (b) 1 1 Intercompany natural gas sales (d) 25 23 Natural gas storage and transportation costs (e) 6 5 (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)

Derivatives and Hedging (Tables

Derivatives and Hedging (Tables)	3 Months Ended
	Mar. 31, 2020
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, 2020 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Cash flow hedges $ 991 $ — $ — $ — $ — $ — Undesignated contracts 2,027 400 1,600 1,050 550 27 Total notional amount (a) $ 3,018 $ 400 $ 1,600 $ 1,050 $ 550 $ 27 December 31, 2019 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Cash flow hedges $ 993 $ — $ — $ — $ — $ — Undesignated contracts 1,277 450 800 250 550 27 Total notional amount (a) $ 2,270 $ 450 $ 800 $ 250 $ 550 $ 27 (a) Duke Energy includes amounts related to consolidated VIEs of $691 million in cash flow hedges as of March 31, 2020 , and $693 million in cash flow hedges as of December 31, 2019 . 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, 2020 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Electricity (GWh) 6,737 — — — — 977 5,760 — Natural gas (millions of dekatherms) 709 145 158 158 — — 4 402 December 31, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Electricity (GWh) 15,858 — — — — 1,887 13,971 — Natural gas (millions of dekatherms) 704 130 160 160 — — 3 411
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, 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 $ 6 $ — $ — $ — $ — $ — $ 2 $ 3 Noncurrent 4 2 1 1 — 1 — — Total Derivative Assets – Commodity Contracts $ 10 $ 2 $ 1 $ 1 $ — $ 1 $ 2 $ 3 Interest Rate Contracts Not Designated as Hedging Instruments Current $ 3 $ — $ 3 $ 3 $ — $ — $ — $ — Noncurrent 1 — 1 1 — — — — Total Derivative Assets – Interest Rate Contracts $ 4 $ — $ 4 $ 4 $ — $ — $ — $ — Equity Securities Contracts Not Designated as Hedging Instruments Noncurrent (a) 20 — 20 — 20 — — — Total Derivative Assets – Equity Securities Contracts $ 20 $ — $ 20 $ — $ 20 $ — $ — $ — Total Derivative Assets $ 34 $ 2 $ 25 $ 5 $ 20 $ 1 $ 2 $ 3 (a) Equity security contracts are current since they were set to expire in May 2020 but are classified as noncurrent assets on the Condensed Consolidated Balance Sheet because the amount is presented within the NDTF. Derivative Liabilities 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 Commodity Contracts Not Designated as Hedging Instruments Current $ 79 $ 40 $ 31 $ 31 $ — $ — $ — $ 8 Noncurrent 130 11 35 20 — — — 83 Total Derivative Liabilities – Commodity Contracts $ 209 $ 51 $ 66 $ 51 $ — $ — $ — $ 91 Interest Rate Contracts Designated as Hedging Instruments Current $ 69 $ — $ — $ — $ — $ — $ — $ — Noncurrent 54 — — — — — — — Not Designated as Hedging Instruments Current 30 — 29 — 29 1 — — Noncurrent 28 23 — — — 6 — — Total Derivative Liabilities – Interest Rate Contracts $ 181 $ 23 $ 29 $ — $ 29 $ 7 $ — $ — Total Derivative Liabilities $ 390 $ 74 $ 95 $ 51 $ 29 $ 7 $ — $ 91 Derivative Assets December 31, 2019 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 $ 17 $ — $ — $ — $ — $ 3 $ 13 $ 1 Noncurrent 1 — — — — 1 — — Total Derivative Assets – Commodity Contracts $ 18 $ — $ — $ — $ — $ 4 $ 13 $ 1 Interest Rate Contracts Not Designated as Hedging Instruments Current 6 — 6 — 6 — — — Total Derivative Assets – Interest Rate Contracts $ 6 $ — $ 6 $ — $ 6 $ — $ — $ — Equity Securities Contracts Not Designated as Hedging Instruments Current 1 — 1 — 1 — — — Total Derivative Assets – Equity Securities Contracts $ 1 $ — $ 1 $ — $ 1 $ — $ — $ — Total Derivative Assets $ 25 $ — $ 7 $ — $ 7 $ 4 $ 13 $ 1 Derivative Liabilities December 31, 2019 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 $ 67 $ 33 $ 26 $ 26 $ — $ — $ 1 $ 7 Noncurrent 156 10 37 22 — — — 110 Total Derivative Liabilities – Commodity Contracts $ 223 $ 43 $ 63 $ 48 $ — $ — $ 1 $ 117 Interest Rate Contracts Designated as Hedging Instruments Current $ 19 $ — $ — $ — $ — $ — $ — $ — Noncurrent 21 — — — — — — — Not Designated as Hedging Instruments Current 8 6 1 1 — 1 — — Noncurrent 5 — — — — 5 — — Total Derivative Liabilities – Interest Rate Contracts $ 53 $ 6 $ 1 $ 1 $ — $ 6 $ — $ — Equity Securities Contracts Not Designated as Hedging Instruments Current 24 — 24 — 24 — — — Total Derivative Liabilities – Equity Securities Contracts $ 24 $ — $ 24 $ — $ 24 $ — $ — $ — Total Derivative Liabilities $ 300 $ 49 $ 88 $ 49 $ 24 $ 6 $ 1 $ 117
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, 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 $ 9 $ — $ 3 $ 3 $ — $ — $ 2 $ 3 Gross amounts offset — — — — — — — — Net amounts presented in Current Assets: Other $ 9 $ — $ 3 $ 3 $ — $ — $ 2 $ 3 Noncurrent Gross amounts recognized $ 25 $ 2 $ 22 $ 2 $ 20 $ 1 $ — $ — Gross amounts offset (3 ) (2 ) (1 ) (1 ) — — — — Net amounts presented in Other Noncurrent Assets: Other $ 2 $ — $ 1 $ 1 $ — $ 1 $ — $ — Net amounts presented in NDTF $ 20 $ — $ 20 $ — $ 20 $ — $ — $ — Derivative Liabilities 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 Current Gross amounts recognized $ 178 $ 40 $ 60 $ 31 $ 29 $ 1 $ — $ 8 Gross amounts offset — — — — — — — — Net amounts presented in Current Liabilities: Other $ 178 $ 40 $ 60 $ 31 $ 29 $ 1 $ — $ 8 Noncurrent Gross amounts recognized $ 212 $ 34 $ 35 $ 20 $ — $ 6 $ — $ 83 Gross amounts offset (3 ) (2 ) (1 ) (1 ) — — — — Net amounts presented in Other Noncurrent Liabilities: Other $ 209 $ 32 $ 34 $ 19 $ — $ 6 $ — $ 83 Derivative Assets December 31, 2019 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 $ 24 $ — $ 7 $ — $ 7 $ 3 $ 13 $ 1 Gross amounts offset (1 ) — (1 ) — (1 ) — — — Net amounts presented in Current Assets: Other $ 23 $ — $ 6 $ — $ 6 $ 3 $ 13 $ 1 Noncurrent Gross amounts recognized $ 1 $ — $ — $ — $ — $ 1 $ — $ — Gross amounts offset — — — — — — — — Net amounts presented in Other Noncurrent Assets: Other $ 1 $ — $ — $ — $ — $ 1 $ — $ — Derivative Liabilities December 31, 2019 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 $ 118 $ 39 $ 51 $ 27 $ 24 $ 1 $ 1 $ 7 Gross amounts offset (24 ) — (24 ) — (24 ) — — — Net amounts presented in Current Liabilities: Other $ 94 $ 39 $ 27 $ 27 $ — $ 1 $ 1 $ 7 Noncurrent Gross amounts recognized $ 182 $ 10 $ 37 $ 22 $ — $ 5 $ — $ 110 Gross amounts offset — — — — — — — — Net amounts presented in Other Noncurrent Liabilities: Other $ 182 $ 10 $ 37 $ 22 $ — $ 5 $ — $ 110
Offsetting Liabilities	Derivative Assets 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 Current Gross amounts recognized $ 9 $ — $ 3 $ 3 $ — $ — $ 2 $ 3 Gross amounts offset — — — — — — — — Net amounts presented in Current Assets: Other $ 9 $ — $ 3 $ 3 $ — $ — $ 2 $ 3 Noncurrent Gross amounts recognized $ 25 $ 2 $ 22 $ 2 $ 20 $ 1 $ — $ — Gross amounts offset (3 ) (2 ) (1 ) (1 ) — — — — Net amounts presented in Other Noncurrent Assets: Other $ 2 $ — $ 1 $ 1 $ — $ 1 $ — $ — Net amounts presented in NDTF $ 20 $ — $ 20 $ — $ 20 $ — $ — $ — Derivative Liabilities 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 Current Gross amounts recognized $ 178 $ 40 $ 60 $ 31 $ 29 $ 1 $ — $ 8 Gross amounts offset — — — — — — — — Net amounts presented in Current Liabilities: Other $ 178 $ 40 $ 60 $ 31 $ 29 $ 1 $ — $ 8 Noncurrent Gross amounts recognized $ 212 $ 34 $ 35 $ 20 $ — $ 6 $ — $ 83 Gross amounts offset (3 ) (2 ) (1 ) (1 ) — — — — Net amounts presented in Other Noncurrent Liabilities: Other $ 209 $ 32 $ 34 $ 19 $ — $ 6 $ — $ 83 Derivative Assets December 31, 2019 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 $ 24 $ — $ 7 $ — $ 7 $ 3 $ 13 $ 1 Gross amounts offset (1 ) — (1 ) — (1 ) — — — Net amounts presented in Current Assets: Other $ 23 $ — $ 6 $ — $ 6 $ 3 $ 13 $ 1 Noncurrent Gross amounts recognized $ 1 $ — $ — $ — $ — $ 1 $ — $ — Gross amounts offset — — — — — — — — Net amounts presented in Other Noncurrent Assets: Other $ 1 $ — $ — $ — $ — $ 1 $ — $ — Derivative Liabilities December 31, 2019 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 $ 118 $ 39 $ 51 $ 27 $ 24 $ 1 $ 1 $ 7 Gross amounts offset (24 ) — (24 ) — (24 ) — — — Net amounts presented in Current Liabilities: Other $ 94 $ 39 $ 27 $ 27 $ — $ 1 $ 1 $ 7 Noncurrent Gross amounts recognized $ 182 $ 10 $ 37 $ 22 $ — $ 5 $ — $ 110 Gross amounts offset — — — — — — — — Net amounts presented in Other Noncurrent Liabilities: Other $ 182 $ 10 $ 37 $ 22 $ — $ 5 $ — $ 110
Derivative Contracts with Contingent Credit Features	The following tables show information with respect to derivative contracts that are in a net liability position and contain objective credit-risk-related payment provisions. March 31, 2020 Duke Duke Duke Energy Progress Energy (in millions) Energy Carolinas Energy Progress Aggregate fair value of derivatives in a net liability position $ 96 $ 45 $ 51 $ 51 Fair value of collateral already posted — — — — Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered 96 45 51 51 December 31, 2019 Duke Duke Duke Energy Progress Energy (in millions) Energy Carolinas Energy Progress Aggregate fair value of derivatives in a net liability position $ 79 $ 35 $ 44 $ 44 Fair value of collateral already posted — — — — Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered 79 35 44 44

Investments in Debt and Equit_2

Investments in Debt and Equity Securities (Tables)	3 Months Ended
	Mar. 31, 2020
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, 2020 December 31, 2019 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 $ — $ — $ 119 $ — $ — $ 101 Equity securities 2,499 170 4,488 3,523 55 5,661 Corporate debt securities 26 16 642 37 1 603 Municipal bonds 10 2 404 13 — 368 U.S. government bonds 70 — 1,212 33 1 1,256 NDTF equity security contracts 20 — 20 — — — Other debt securities 4 3 163 3 — 141 Total NDTF Investments $ 2,629 $ 191 $ 7,048 $ 3,609 $ 57 $ 8,130 Other Investments Cash and cash equivalents $ — $ — $ 78 $ — $ — $ 52 Equity securities 31 1 95 57 — 122 Corporate debt securities — — 89 3 — 67 Municipal bonds 6 1 98 4 — 94 U.S. government bonds 5 — 51 2 — 41 Other debt securities — — 52 — — 56 Total Other Investments $ 42 $ 2 $ 463 $ 66 $ — $ 432 Total Investments $ 2,671 $ 193 $ 7,511 $ 3,675 $ 57 $ 8,562
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, 2020 December 31, 2019 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 $ — $ — $ 119 $ — $ — $ 101 Equity securities 2,499 170 4,488 3,523 55 5,661 Corporate debt securities 26 16 642 37 1 603 Municipal bonds 10 2 404 13 — 368 U.S. government bonds 70 — 1,212 33 1 1,256 NDTF equity security contracts 20 — 20 — — — Other debt securities 4 3 163 3 — 141 Total NDTF Investments $ 2,629 $ 191 $ 7,048 $ 3,609 $ 57 $ 8,130 Other Investments Cash and cash equivalents $ — $ — $ 78 $ — $ — $ 52 Equity securities 31 1 95 57 — 122 Corporate debt securities — — 89 3 — 67 Municipal bonds 6 1 98 4 — 94 U.S. government bonds 5 — 51 2 — 41 Other debt securities — — 52 — — 56 Total Other Investments $ 42 $ 2 $ 463 $ 66 $ — $ 432 Total Investments $ 2,671 $ 193 $ 7,511 $ 3,675 $ 57 $ 8,562
Investments Classified by Contractual Maturity Date	The table below summarizes the maturity date for debt securities. March 31, 2020 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Indiana Due in one year or less $ 333 $ 25 $ 302 $ 26 $ 276 $ 3 Due after one through five years 538 234 236 227 9 17 Due after five through 10 years 465 188 214 207 7 7 Due after 10 years 1,375 734 541 506 35 16 Total $ 2,711 $ 1,181 $ 1,293 $ 966 $ 327 $ 43
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, 2020 , and 2019 , were as follows. Three Months Ended (in millions) March 31, 2020 March 31, 2019 FV-NI: Realized gains $ 23 $ 35 Realized losses 65 30 AFS: Realized gains 20 10 Realized losses 6 11
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, 2020 December 31, 2019 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 $ — $ — $ 33 $ — $ — $ 21 Equity securities 1,355 81 2,498 1,914 8 3,154 Corporate debt securities 15 12 392 21 1 361 Municipal bonds 3 1 128 3 — 96 U.S. government bonds 35 — 502 16 1 578 Other debt securities 3 3 159 3 — 137 Total NDTF Investments $ 1,411 $ 97 $ 3,712 $ 1,957 $ 10 $ 4,347
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, 2020 December 31, 2019 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 $ — $ — $ 33 $ — $ — $ 21 Equity securities 1,355 81 2,498 1,914 8 3,154 Corporate debt securities 15 12 392 21 1 361 Municipal bonds 3 1 128 3 — 96 U.S. government bonds 35 — 502 16 1 578 Other debt securities 3 3 159 3 — 137 Total NDTF Investments $ 1,411 $ 97 $ 3,712 $ 1,957 $ 10 $ 4,347
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, 2020 , and 2019 , were as follows. Three Months Ended (in millions) March 31, 2020 March 31, 2019 FV-NI: Realized gains $ 9 $ 23 Realized losses 45 21 AFS: Realized gains 12 9 Realized losses 5 10
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, 2020 December 31, 2019 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 $ — $ — $ 86 $ — $ — $ 80 Equity securities 1,144 89 1,990 1,609 47 2,507 Corporate debt securities 11 4 250 16 — 242 Municipal bonds 7 1 276 10 — 272 U.S. government bonds 35 — 710 17 — 678 NDTF equity security contracts 20 — 20 — — — Other debt securities 1 — 4 — — 4 Total NDTF Investments $ 1,218 $ 94 $ 3,336 $ 1,652 $ 47 $ 3,783 Other Investments Cash and cash equivalents $ — $ — $ 69 $ — $ — $ 49 Municipal bonds 5 — 53 3 — 51 Total Other Investments $ 5 $ — $ 122 $ 3 $ — $ 100 Total Investments $ 1,223 $ 94 $ 3,458 $ 1,655 $ 47 $ 3,883
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, 2020 December 31, 2019 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 $ — $ — $ 86 $ — $ — $ 80 Equity securities 1,144 89 1,990 1,609 47 2,507 Corporate debt securities 11 4 250 16 — 242 Municipal bonds 7 1 276 10 — 272 U.S. government bonds 35 — 710 17 — 678 NDTF equity security contracts 20 — 20 — — — Other debt securities 1 — 4 — — 4 Total NDTF Investments $ 1,218 $ 94 $ 3,336 $ 1,652 $ 47 $ 3,783 Other Investments Cash and cash equivalents $ — $ — $ 69 $ — $ — $ 49 Municipal bonds 5 — 53 3 — 51 Total Other Investments $ 5 $ — $ 122 $ 3 $ — $ 100 Total Investments $ 1,223 $ 94 $ 3,458 $ 1,655 $ 47 $ 3,883
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, 2020 , and 2019 , were as follows. Three Months Ended (in millions) March 31, 2020 March 31, 2019 FV-NI: Realized gains $ 14 $ 12 Realized losses 20 9 AFS: Realized gains 5 1 Realized losses 1 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, 2020 December 31, 2019 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 $ — $ — $ 51 $ — $ — $ 53 Equity securities 881 79 1,631 1,258 21 2,077 Corporate debt securities 11 4 250 16 — 242 Municipal bonds 7 1 276 10 — 272 U.S. government bonds 34 — 436 16 — 403 Other debt securities 1 — 4 — — 4 Total NDTF Investments $ 934 $ 84 $ 2,648 $ 1,300 $ 21 $ 3,051 Other Investments Cash and cash equivalents $ — $ — $ 2 $ — $ — $ 2 Total Other Investments $ — $ — $ 2 $ — $ — $ 2 Total Investments $ 934 $ 84 $ 2,650 $ 1,300 $ 21 $ 3,053
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, 2020 December 31, 2019 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 $ — $ — $ 51 $ — $ — $ 53 Equity securities 881 79 1,631 1,258 21 2,077 Corporate debt securities 11 4 250 16 — 242 Municipal bonds 7 1 276 10 — 272 U.S. government bonds 34 — 436 16 — 403 Other debt securities 1 — 4 — — 4 Total NDTF Investments $ 934 $ 84 $ 2,648 $ 1,300 $ 21 $ 3,051 Other Investments Cash and cash equivalents $ — $ — $ 2 $ — $ — $ 2 Total Other Investments $ — $ — $ 2 $ — $ — $ 2 Total Investments $ 934 $ 84 $ 2,650 $ 1,300 $ 21 $ 3,053
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, 2020 , and 2019 , were as follows. Three Months Ended (in millions) March 31, 2020 March 31, 2019 FV-NI: Realized gains $ 14 $ 10 Realized losses 20 8 AFS: Realized gains 5 1 Realized losses 1 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, 2020 December 31, 2019 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 $ — $ — $ 27 Equity securities 263 10 359 351 26 430 U.S. government bonds 1 — 274 1 — 275 NDTF equity security contracts 20 — 20 — — — Total NDTF Investments (a) $ 284 $ 10 $ 688 $ 352 $ 26 $ 732 Other Investments Cash and cash equivalents $ — $ — $ 3 $ — $ — $ 4 Municipal bonds 5 — 53 3 — 51 Total Other Investments $ 5 $ — $ 56 $ 3 $ — $ 55 Total Investments $ 289 $ 10 $ 744 $ 355 $ 26 $ 787 (a) During the three months ended March 31, 2020 , Duke Energy Florida continued to receive 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, 2020 December 31, 2019 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 $ — $ — $ 27 Equity securities 263 10 359 351 26 430 U.S. government bonds 1 — 274 1 — 275 NDTF equity security contracts 20 — 20 — — — Total NDTF Investments (a) $ 284 $ 10 $ 688 $ 352 $ 26 $ 732 Other Investments Cash and cash equivalents $ — $ — $ 3 $ — $ — $ 4 Municipal bonds 5 — 53 3 — 51 Total Other Investments $ 5 $ — $ 56 $ 3 $ — $ 55 Total Investments $ 289 $ 10 $ 744 $ 355 $ 26 $ 787 (a) During the three months ended March 31, 2020 , Duke Energy Florida continued to receive 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, 2020 December 31, 2019 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 Equity securities $ 26 $ 1 $ 63 $ 43 $ — $ 81 Corporate debt securities — — 4 — — 6 Municipal bonds 1 1 36 1 — 36 U.S. government bonds — — 3 — — 2 Total Investments $ 27 $ 2 $ 106 $ 44 $ — $ 125
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, 2020 December 31, 2019 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 Equity securities $ 26 $ 1 $ 63 $ 43 $ — $ 81 Corporate debt securities — — 4 — — 6 Municipal bonds 1 1 36 1 — 36 U.S. government bonds — — 3 — — 2 Total Investments $ 27 $ 2 $ 106 $ 44 $ — $ 125

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2020
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, 2020 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not Categorized NDTF equity securities $ 4,488 $ 4,440 $ — $ — $ 48 NDTF debt securities 2,540 767 1,773 — — Other equity securities 95 95 — — — Other debt securities 368 126 242 — — NDTF equity security contracts 20 — 20 — — Derivative assets 34 3 28 3 — Total assets 7,545 5,431 2,063 3 48 Derivative liabilities (390 ) (49 ) (250 ) (91 ) — Net assets (liabilities) $ 7,155 $ 5,382 $ 1,813 $ (88 ) $ 48 December 31, 2019 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not Categorized NDTF equity securities $ 5,684 $ 5,633 $ — $ — $ 51 NDTF debt securities 2,469 826 1,643 — — Other equity securities 122 122 — — — Other debt securities 310 91 219 — — Derivative assets 25 3 7 15 — Total assets 8,610 6,675 1,869 15 51 NDTF equity security contracts (23 ) — (23 ) — — Derivative liabilities (277 ) (15 ) (145 ) (117 ) — Net assets (liabilities) $ 8,310 $ 6,660 $ 1,701 $ (102 ) $ 51
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) 2020 2019 Balance at beginning of period $ (102 ) $ (113 ) Purchases, sales, issuances and settlements: Settlements (9 ) (12 ) Total gains included on the Condensed Consolidated Balance Sheet 23 10 Balance at end of period $ (88 ) $ (115 )
Quantitative Information Table - Level 3	The following tables include quantitative information about the Duke Energy Registrants' derivatives classified as Level 3. March 31, 2020 Weighted Fair Value Average Investment Type (in millions) Valuation Technique Unobservable Input Range Range Duke Energy Ohio FTRs $ 1 RTO auction pricing FTR price – per MWh $ 0.04 - $ 3.29 $ 1.03 Duke Energy Indiana FTRs 2 RTO auction pricing FTR price – per MWh (0.37 ) - 6.06 0.54 Piedmont Natural gas contracts (91 ) Discounted cash flow Forward natural gas curves – price per MMBtu 1.64 - 2.41 1.94 Duke Energy Total Level 3 derivatives $ (88 ) December 31, 2019 Weighted Fair Value Average Investment Type (in millions) Valuation Technique Unobservable Input Range Range Duke Energy Ohio FTRs $ 4 RTO auction pricing FTR price – per MWh $ 0.59 - $ 3.47 $ 2.07 Duke Energy Indiana FTRs 11 RTO auction pricing FTR price – per MWh (0.66 ) - 9.24 1.15 Piedmont Natural gas contracts (117 ) Discounted cash flow Forward natural gas curves – price per MMBtu 1.59 - 2.46 1.91 Duke Energy Total Level 3 derivatives $ (102 )
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, 2020 December 31, 2019 (in millions) Book Value Fair Value Book Value Fair Value Duke Energy (a) $ 61,388 $ 65,644 $ 58,126 $ 63,062 Duke Energy Carolinas 12,807 14,312 11,900 13,516 Progress Energy 19,355 21,802 19,634 22,291 Duke Energy Progress 9,059 9,798 9,058 9,934 Duke Energy Florida 7,706 8,831 7,987 9,131 Duke Energy Ohio 2,620 2,904 2,619 2,964 Duke Energy Indiana 4,603 5,433 4,057 4,800 Piedmont 2,385 2,551 2,384 2,642 (a) Book value of long-term debt includes $1.4 billion at March 31, 2020 , and $1.5 billion at December 31, 2019 , 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.
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, 2020 (in millions) Total Fair Value Level 1 Level 2 Not Categorized NDTF equity securities $ 2,498 $ 2,450 $ — $ 48 NDTF debt securities 1,214 182 1,032 — Derivative assets 2 — 2 — Total assets 3,714 2,632 1,034 48 Derivative liabilities (74 ) — (74 ) — Net assets $ 3,640 $ 2,632 $ 960 $ 48 December 31, 2019 (in millions) Total Fair Value Level 1 Level 2 Not Categorized NDTF equity securities $ 3,154 $ 3,103 $ — $ 51 NDTF debt securities 1,193 227 966 — Total assets 4,347 3,330 966 51 Derivative liabilities (49 ) — (49 ) — Net assets $ 4,298 $ 3,330 $ 917 $ 51
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, 2020 December 31, 2019 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 NDTF equity securities $ 1,990 $ 1,990 $ — $ 2,530 $ 2,530 $ — NDTF debt securities 1,326 585 741 1,276 599 677 Other debt securities 122 69 53 100 49 51 NDTF equity security contracts 20 — 20 — — — Derivative assets 25 — 25 7 — 7 Total assets 3,483 2,644 839 3,913 3,178 735 NDTF equity security contracts — — — (23 ) — (23 ) Derivative liabilities (95 ) — (95 ) (65 ) — (65 ) Net assets $ 3,388 $ 2,644 $ 744 $ 3,825 $ 3,178 $ 647
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, 2020 December 31, 2019 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 NDTF equity securities $ 1,631 $ 1,631 $ — $ 2,077 $ 2,077 $ — NDTF debt securities 1,017 276 741 974 297 677 Other debt securities 2 2 — 2 2 — Derivative assets 5 — 5 — — — Total assets 2,655 1,909 746 3,053 2,376 677 Derivative liabilities (51 ) — (51 ) (49 ) — (49 ) Net assets $ 2,604 $ 1,909 $ 695 $ 3,004 $ 2,376 $ 628
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, 2020 December 31, 2019 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 NDTF equity securities $ 359 $ 359 $ — $ 453 $ 453 $ — NDTF debt securities 309 309 — 302 302 — Other debt securities 56 3 53 55 4 51 NDTF equity security contracts 20 — 20 — — — Derivative assets — — — 7 — 7 Total assets 744 671 73 817 759 58 NDTF equity security contracts — — — (23 ) — (23 ) Derivative liabilities (29 ) — (29 ) (1 ) — (1 ) Net assets $ 715 $ 671 $ 44 $ 793 $ 759 $ 34
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, 2020 December 31, 2019 (in millions) Total Fair Value Level 1 Level 2 Level 3 Total Fair Value Level 1 Level 2 Level 3 Other equity securities $ 63 $ 63 $ — $ — $ 81 $ 81 $ — $ — Other debt securities 43 — 43 — 44 — 44 — Derivative assets 2 — — 2 13 2 — 11 Total assets $ 108 $ 63 $ 43 $ 2 $ 138 $ 83 $ 44 $ 11 Derivative liabilities — — — — (1 ) (1 ) — — Net assets $ 108 $ 63 $ 43 $ 2 $ 137 $ 82 $ 44 $ 11
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) 2020 2019 Balance at beginning of period $ 11 $ 22 Purchases, sales, issuances and settlements: Settlements (6 ) (10 ) Total losses included on the Condensed Consolidated Balance Sheet (3 ) (7 ) Balance at end of period $ 2 $ 5
Piedmont Natural Gas
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, 2020 December 31, 2019 (in millions) Total Fair Value Level 1 Level 3 Total Fair Value Level 1 Level 3 Derivative assets $ 3 $ 3 $ — $ 1 $ 1 $ — Derivative liabilities (91 ) — (91 ) (117 ) — (117 ) Net (liabilities) assets $ (88 ) $ 3 $ (91 ) $ (116 ) $ 1 $ (117 )
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) 2020 2019 Balance at beginning of period $ (117 ) $ (141 ) Total gains and settlements 26 20 Balance at end of period $ (91 ) $ (121 )

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	3 Months Ended
	Mar. 31, 2020
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 2021 Credit facility amount $ 350 $ 475 $ 375 $ 250 Amounts borrowed at March 31, 2020 350 475 325 250 Amounts borrowed at December 31, 2019 350 474 325 250 Restricted Receivables at March 31, 2020 467 616 410 331 Restricted Receivables at December 31, 2019 522 642 489 336
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, 2020 Duke Energy Duke Duke Pipeline Commercial Other Energy Energy (in millions) Investments Renewables VIEs Total Ohio Indiana Receivables from affiliated companies $ — $ (1 ) $ — $ (1 ) $ 39 $ 48 Investments in equity method unconsolidated affiliates 1,243 371 — 1,614 — — Total assets $ 1,243 $ 370 $ — $ 1,613 $ 39 $ 48 Taxes accrued (1 ) — — (1 ) — — Other current liabilities — — 3 3 — — Deferred income taxes 69 — — 69 — — Other noncurrent liabilities 105 — 11 116 — — Total liabilities $ 173 $ — $ 14 $ 187 $ — $ — Net assets (liabilities) $ 1,070 $ 370 $ (14 ) $ 1,426 $ 39 $ 48 December 31, 2019 Duke Energy Duke Duke Pipeline Commercial Other Energy Energy (in millions) Investments Renewables VIEs Total Ohio Indiana Receivables from affiliated companies $ — $ (1 ) $ — $ (1 ) $ 64 $ 77 Investments in equity method unconsolidated affiliates 1,179 300 — 1,479 — — Total assets $ 1,179 $ 299 $ — $ 1,478 $ 64 $ 77 Taxes accrued (1 ) — — (1 ) — — Other current liabilities — — 4 4 — — Deferred income taxes 59 — — 59 — — Other noncurrent liabilities — — 11 11 — — Total liabilities $ 58 $ — $ 15 $ 73 $ — $ — Net assets (liabilities) $ 1,121 $ 299 $ (15 ) $ 1,405 $ 64 $ 77
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, 2020 December 31, 2019 Receivables of VIEs $ 4 $ 5 Regulatory Assets: Current 53 52 Current Assets: Other 13 39 Other Noncurrent Assets: Regulatory assets 980 989 Current Liabilities: Other 2 10 Current maturities of long-term debt 54 54 Long-Term Debt 1,028 1,057
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, 2020 December 31, 2019 Current Assets: Other $ 287 $ 203 Property, Plant and Equipment: Cost 6,106 5,747 Accumulated depreciation and amortization (1,094 ) (1,041 ) Other Noncurrent Assets: Other 82 106 Current maturities of long-term debt 162 162 Long-Term Debt 1,538 1,541 Other Noncurrent Liabilities: AROs 129 127 Other Noncurrent Liabilities: Other 258 228
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, 2020 December 31, 2019 March 31, 2020 December 31, 2019 Receivables sold $ 234 $ 253 $ 274 $ 307 Less: Retained interests 39 64 48 77 Net receivables sold $ 195 $ 189 $ 226 $ 230 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) 2020 2019 2020 2019 Sales Receivables sold $ 537 $ 575 $ 647 $ 734 Loss recognized on sale 4 4 4 5 Cash flows Cash proceeds from receivables sold $ 559 $ 597 $ 672 $ 758 Return received on retained interests 2 2 2 3
Pipeline Investments | VIE not primary beneficiary
Variable Interest Entities [Line Items]
Schedule Of Variable Interest Entities	The table below presents Duke Energy's ownership interest and investment balances in these joint ventures. VIE Investment Amount (in millions) Ownership March 31, December 31, Entity Name Interest 2020 2019 ACP (a) 47 % $ 1,243 $ 1,179 Constitution (b) 24 % — — Total $ 1,243 $ 1,179 (a) Duke Energy evaluated this investment for impairment as of March 31, 2020 , and December 31, 2019 , and determined that fair value approximated carrying value and therefore no impairment was necessary. (b) During the year ended December 31, 2019, Duke Energy recorded an OTTI related to Constitution. This charge resulted in the full write-down of Duke Energy's investment in Constitution.

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction	Estimated remaining performance obligations are as follows: Remaining Performance Obligations (in millions) 2020 2021 2022 2023 2024 Thereafter Total Piedmont $ 51 $ 65 $ 64 $ 61 $ 58 $ 376 $ 675 Remaining Performance Obligations (in millions) 2020 2021 2022 2023 2024 Thereafter Total Progress Energy $ 84 $ 92 $ 87 $ 44 $ 45 $ 58 $ 410 Duke Energy Progress 6 8 8 8 8 — 38 Duke Energy Florida 78 84 79 36 37 58 372 Duke Energy Indiana 8 5 — — — — 13
Disaggregation of Revenue	Disaggregated revenues are presented as follows: 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, 2019 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 $ 2,370 $ 760 $ 1,114 $ 536 $ 578 $ 189 $ 306 $ — General 1,427 496 632 306 326 103 197 — Industrial 711 266 222 161 61 33 190 — Wholesale 541 119 353 315 38 14 54 — Other revenues 172 78 172 125 47 16 17 — Total Electric Utilities and Infrastructure revenue from contracts with customers $ 5,221 $ 1,719 $ 2,493 $ 1,443 $ 1,050 $ 355 $ 764 $ — Gas Utilities and Infrastructure Residential $ 414 $ — $ — $ — $ — $ 112 $ — $ 302 Commercial 206 — — — — 49 — 157 Industrial 48 — — — — 7 — 42 Power Generation — — — — — — — 13 Other revenues 63 — — — — 8 — 56 Total Gas Utilities and Infrastructure revenue from contracts with customers $ 731 $ — $ — $ — $ — $ 176 $ — $ 570 Commercial Renewables Revenue from contracts with customers $ 42 $ — $ — $ — $ — $ — $ — $ — Other Revenue from contracts with customers $ 4 $ — $ — $ — $ — $ — $ — $ — Total revenue from contracts with customers $ 5,998 $ 1,719 $ 2,493 $ 1,443 $ 1,050 $ 531 $ 764 $ 570 Other revenue sources (a) $ 165 $ 25 $ 79 $ 41 $ 36 $ — $ 4 $ 9 Total revenues $ 6,163 $ 1,744 $ 2,572 $ 1,484 $ 1,086 $ 531 $ 768 $ 579 (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	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 following table presents the reserve for credit losses for trade and other receivables based on adoption of the new standard. 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 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
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, 2020 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Unbilled Receivables $ 716 $ 285 $ 195 $ 85 $ 110 $ 1 $ 16 $ 32 0-30 days 1,584 448 585 321 262 45 24 134 30-60 days 216 69 67 44 23 9 1 18 60-90 days 65 18 20 14 6 2 1 5 90+ days 145 19 57 32 25 32 11 11 Trade and Other Receivables $ 2,726 $ 839 $ 924 $ 496 $ 426 $ 89 $ 53 $ 200 Unbilled revenues are included within Receivables and Receivables of VIEs on the Condensed Consolidated Balance Sheets as shown in the following table. (in millions) March 31, 2020 December 31, 2019 Duke Energy $ 716 $ 843 Duke Energy Carolinas 285 298 Progress Energy 195 217 Duke Energy Progress 85 122 Duke Energy Florida 110 95 Duke Energy Ohio 1 1 Duke Energy Indiana 16 16 Piedmont 32 78 (in millions) March 31, 2020 December 31, 2019 Duke Energy Ohio $ 61 $ 82 Duke Energy Indiana 94 115

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2020
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) 2020 2019 Income from continuing operations available to Duke Energy common stockholders excluding impact of participating securities and including accumulated preferred stock dividends adjustment $ 911 $ 898 Weighted average common shares outstanding – basic 734 727 Equity forwards 2 — Weighted average common shares outstanding – diluted 736 727 EPS from continuing operations available to Duke Energy common stockholders Basic and diluted $ 1.24 $ 1.24 Potentially dilutive items excluded from the calculation (a) 2 2 Dividends declared per common share $ 0.945 $ 0.9275 Dividends declared on Series A preferred stock per depositary share (b) $ 0.359 $ — Dividends declared on Series B preferred stock per share (c) $ 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
	Mar. 31, 2020
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, 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 ) Three Months Ended March 31, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Service cost $ 37 $ 12 $ 11 $ 6 $ 4 $ 1 $ 2 $ 1 Interest cost on projected benefit obligation 83 20 26 12 14 5 6 3 Expected return on plan assets (143 ) (38 ) (44 ) (23 ) (22 ) (8 ) (11 ) (5 ) Amortization of actuarial loss 24 6 9 3 6 1 2 2 Amortization of prior service credit (8 ) (2 ) (1 ) — — — — (3 ) Net periodic pension costs $ (7 ) $ (2 ) $ 1 $ (2 ) $ 2 $ (1 ) $ (1 ) $ (2 )

Income Taxes (Tables)

Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2020
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, 2020 2019 Duke Energy 13.3 % 9.6 % Duke Energy Carolinas 16.1 % 17.7 % Progress Energy 17.5 % 17.3 % Duke Energy Progress 17.1 % 17.8 % Duke Energy Florida 20.0 % 19.3 % Duke Energy Ohio 17.7 % 16.9 % Duke Energy Indiana 20.8 % 24.1 % Piedmont 10.1 % 21.8 %

Organization and Basis of Pre_4

Organization and Basis of Presentation (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Noncontrolling Interest [Line Items]
Sale of noncontrolling interests	$ 103	$ 6
Net Income (Loss) Allocation to Noncontrolling Tax Equity Members	$ 49	$ 7

Organization and Basis of Pre_5

Organization and Basis of Presentation (Schedule of Cash and Cash Equivalents) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Current Assets
Cash and cash equivalents	$ 1,450	$ 311
Other	185	222
Other Noncurrent Assets
Other	63	40
Total cash, cash equivalents and restricted cash	1,698	573	$ 550	$ 591
Progress Energy
Current Assets
Cash and cash equivalents	52	48
Other	13	39
Other Noncurrent Assets
Other	60	39
Total cash, cash equivalents and restricted cash	125	126	95	112
Duke Energy Florida
Current Assets
Cash and cash equivalents	12	17
Other	13	39
Other Noncurrent Assets
Total cash, cash equivalents and restricted cash	$ 25	$ 56	$ 20	$ 75

Organization and Basis of Pre_6

Organization and Basis of Presentation (Schedule of Inventory) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Public Utilities, Inventory [Line Items]
Inventory	$ 3,324	$ 3,232
Materials and supplies
Public Utilities, Inventory [Line Items]
Inventory	2,280	2,297
Coal
Public Utilities, Inventory [Line Items]
Inventory	742	586
Natural gas, oil and other fuel
Public Utilities, Inventory [Line Items]
Inventory	302	349
Duke Energy Carolinas
Public Utilities, Inventory [Line Items]
Inventory	1,067	996
Duke Energy Carolinas | Materials and supplies
Public Utilities, Inventory [Line Items]
Inventory	759	768
Duke Energy Carolinas | Coal
Public Utilities, Inventory [Line Items]
Inventory	268	187
Duke Energy Carolinas | Natural gas, oil and other fuel
Public Utilities, Inventory [Line Items]
Inventory	40	41
Progress Energy
Public Utilities, Inventory [Line Items]
Inventory	1,463	1,423
Progress Energy | Materials and supplies
Public Utilities, Inventory [Line Items]
Inventory	1,018	1,038
Progress Energy | Coal
Public Utilities, Inventory [Line Items]
Inventory	246	186
Progress Energy | Natural gas, oil and other fuel
Public Utilities, Inventory [Line Items]
Inventory	199	199
Duke Energy Progress
Public Utilities, Inventory [Line Items]
Inventory	956	934
Duke Energy Progress | Materials and supplies
Public Utilities, Inventory [Line Items]
Inventory	678	686
Duke Energy Progress | Coal
Public Utilities, Inventory [Line Items]
Inventory	167	138
Duke Energy Progress | Natural gas, oil and other fuel
Public Utilities, Inventory [Line Items]
Inventory	111	110
Duke Energy Florida
Public Utilities, Inventory [Line Items]
Inventory	508	489
Duke Energy Florida | Materials and supplies
Public Utilities, Inventory [Line Items]
Inventory	340	351
Duke Energy Florida | Coal
Public Utilities, Inventory [Line Items]
Inventory	79	48
Duke Energy Florida | Natural gas, oil and other fuel
Public Utilities, Inventory [Line Items]
Inventory	89	90
Duke Energy Ohio
Public Utilities, Inventory [Line Items]
Inventory	121	135
Duke Energy Ohio | Materials and supplies
Public Utilities, Inventory [Line Items]
Inventory	83	79
Duke Energy Ohio | Coal
Public Utilities, Inventory [Line Items]
Inventory	10	15
Duke Energy Ohio | Natural gas, oil and other fuel
Public Utilities, Inventory [Line Items]
Inventory	28	41
Duke Energy Indiana
Public Utilities, Inventory [Line Items]
Inventory	538	517
Duke Energy Indiana | Materials and supplies
Public Utilities, Inventory [Line Items]
Inventory	319	318
Duke Energy Indiana | Coal
Public Utilities, Inventory [Line Items]
Inventory	218	198
Duke Energy Indiana | Natural gas, oil and other fuel
Public Utilities, Inventory [Line Items]
Inventory	1	1
Piedmont Natural Gas
Public Utilities, Inventory [Line Items]
Inventory	39	72
Piedmont Natural Gas | Materials and supplies
Public Utilities, Inventory [Line Items]
Inventory	5	5
Piedmont Natural Gas | Natural gas, oil and other fuel
Public Utilities, Inventory [Line Items]
Inventory	$ 34	$ 67

Organization and Basis of Pre_7

Organization and Basis of Presentation (Schedule of New Accounting Pronouncements) (Details) - ASU 2016-13 $ in Millions	Jan. 01, 2020USD ($)
Retained Earnings Adjustments [Line Items]
Total pretax impact to Retained Earnings	$ 120
Duke Energy Carolinas
Retained Earnings Adjustments [Line Items]
Total pretax impact to Retained Earnings	16
Progress Energy
Retained Earnings Adjustments [Line Items]
Total pretax impact to Retained Earnings	2
Duke Energy Progress
Retained Earnings Adjustments [Line Items]
Total pretax impact to Retained Earnings	1
Duke Energy Florida
Retained Earnings Adjustments [Line Items]
Total pretax impact to Retained Earnings	1
Piedmont Natural Gas
Retained Earnings Adjustments [Line Items]
Total pretax impact to Retained Earnings	$ 1

Business Segments (Business Seg

Business Segments (Business Segment Data) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Operating revenues	$ 5,949	$ 6,163
Segment income (loss)	899	900
Add: Noncontrolling interests	(48)	(7)
Add: Preferred stock dividend	39
Net Income	890	893
Segment assets	160,072		$ 158,838
Electric Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	5,174	5,321
Gas Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	640	732
Commercial Renewables
Segment Reporting Information [Line Items]
Operating revenues	129	106
Total Reportable Segments
Segment Reporting Information [Line Items]
Operating revenues	5,943	6,159
Other
Segment Reporting Information [Line Items]
Operating revenues	6	4
Operating Segments | Electric Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	5,183	5,329
Segment income (loss)	705	750
Segment assets	134,838
Operating Segments | Gas Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	664	756
Segment income (loss)	249	226
Segment assets	14,098
Operating Segments | Commercial Renewables
Segment Reporting Information [Line Items]
Operating revenues	129	106
Segment income (loss)	57	13
Segment assets	6,184
Operating Segments | Total Reportable Segments
Segment Reporting Information [Line Items]
Operating revenues	5,976	6,191
Segment income (loss)	1,011	989
Segment assets	155,120
Other | Other
Segment Reporting Information [Line Items]
Operating revenues	23	21
Segment income (loss)	(112)	(89)
Segment assets	4,964
Eliminations
Segment Reporting Information [Line Items]
Operating revenues	(50)	(49)
Segment assets	(12)
Eliminations | Electric Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	9	8
Eliminations | Gas Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	24	24
Eliminations | Total Reportable Segments
Segment Reporting Information [Line Items]
Operating revenues	33	32
Eliminations | Other
Segment Reporting Information [Line Items]
Operating revenues	17	17
Duke Energy Carolinas
Segment Reporting Information [Line Items]
Operating revenues	1,748	1,744
Segment assets	44,051		44,053
Duke Energy Carolinas | Other
Segment Reporting Information [Line Items]
Segment income (loss)	98
Duke Energy Ohio
Segment Reporting Information [Line Items]
Operating revenues	498	531
Segment income (loss)	65	69
Segment assets	9,397		$ 9,338
Duke Energy Ohio | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues		531
Segment income (loss)		71
Duke Energy Ohio | Operating Segments | Electric Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	346	355
Segment income (loss)	30	36
Segment assets	6,238
Duke Energy Ohio | Operating Segments | Gas Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	152	176
Segment income (loss)	36	35
Segment assets	3,135
Duke Energy Ohio | Operating Segments | Total Reportable Segments
Segment Reporting Information [Line Items]
Operating revenues	498
Segment income (loss)	66
Segment assets	9,373
Duke Energy Ohio | Other
Segment Reporting Information [Line Items]
Segment income (loss)		$ (2)
Duke Energy Ohio | Other | Other
Segment Reporting Information [Line Items]
Segment income (loss)	(1)
Segment assets	26
Duke Energy Ohio | Eliminations
Segment Reporting Information [Line Items]
Segment assets	$ (2)

Business Segments (Narrative) (

Business Segments (Narrative) (Details)	3 Months Ended
	Mar. 31, 2020segment
Duke Energy Ohio
Segment Reporting Information [Line Items]
Number of reportable segments	2

Regulatory Matters (Regulatory

Regulatory Matters (Regulatory Matters Narrative - Duke Energy Carolinas) (Details) - Duke Energy Carolinas - USD ($) $ in Millions	Sep. 30, 2019	May 21, 2019	Nov. 08, 2018	Feb. 28, 2018	Aug. 25, 2017
2017 North Carolina Rate Case | NCUC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount					$ 647
Requested rate increase, percentage					13.60%
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%
2019 North Carolina Rate Case | NCUC
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
South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount			$ 168
Requested rate increase, percentage			10.00%
Change in tax rate, deferred tax liability, income tax benefit		$ 66	$ 66
Measurement period adjustment, income tax expense (benefit)		$ 45	46
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%
State and local jurisdiction | North Carolina Department of Revenue | South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
State and local taxes reduction amount		$ 17	17
Regulatory asset, amortization period		5 years
Asset retirement obligations - coal ash | South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
Regulatory assets		$ 96	$ 242
Regulatory asset, amortization period		5 years	5 years
Recovery costs denied		$ 115
Asset retirement obligations - unprotected EDIT, Property, Plant and Equipment | South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period		20 years
Asset retirement obligations - unprotected EDIT | South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period		5 years
Asset retirement obligations - deferred revenue | South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period		5 years
Deferred project costs | South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
Regulatory assets		$ 125
Regulatory asset, amortization period		12 years

Regulatory Matters (Regulator_2

Regulatory Matters (Regulatory Matters Narrative - Duke Energy Progress) (Details) - Duke Energy Progress customer in Thousands, $ in Millions	Jan. 29, 2020USD ($)MW	Oct. 30, 2019USD ($)	May 21, 2019USD ($)	Nov. 08, 2018USD ($)	Nov. 22, 2017	Jun. 01, 2017USD ($)	Mar. 31, 2020USD ($)	Feb. 07, 2020USD ($)	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)customer	Mar. 28, 2016USD ($)
2017 North Carolina Rate Case | NCUC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount						$ 477
Requested rate increase, percentage						14.90%
Requested rate increase (decrease), amended amount						$ 420
Requested rate increase (decrease) amended, percentage						13.00%
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%
2019 North Carolina Rate Case | NCUC
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
Hurricane Dorian storm damage
Public Utilities, General Disclosures [Line Items]
Estimated storm costs - O&M										$ 177
Estimated storm costs - capital investments										$ 4
Storm deferral - O&M								$ 22
South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount				$ 59
Requested rate increase, percentage				10.30%
Change in tax rate, deferred tax liability, income tax benefit			$ 17	$ 17
Measurement period adjustment, income tax expense (benefit)			$ 12	10
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%
Western Carolinas Modernization Plan | NCUC
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period							10 years
Estimated capital cost											$ 893
NORTH CAROLINA | Hurricane Dorian storm damage
Public Utilities, General Disclosures [Line Items]
Customers experiencing outages | customer										270
SOUTH CAROLINA | Hurricane Dorian storm damage
Public Utilities, General Disclosures [Line Items]
Customers experiencing outages | customer										30
Storm Costs [Member] | Hurricane Dorian storm damage
Public Utilities, General Disclosures [Line Items]
Regulatory assets							$ 151		$ 179
Asset retirement obligations - coal ash | South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
Regulatory assets			$ 4	$ 51
Recovery costs denied			$ 65
Regulatory asset, amortization period			5 years	5 years
Asset retirement obligations - unprotected EDIT, Property, Plant and Equipment | South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period			20 years
Asset retirement obligations - unprotected EDIT | South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period			5 years
Asset retirement obligations - deferred revenue | South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period			3 years
State and local jurisdiction | North Carolina Department of Revenue | South Carolina Rate Case 2018 | PSCSC
Public Utilities, General Disclosures [Line Items]
State and local taxes reduction amount			$ (12)	$ (12)
Asheville Plant
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	376
Generation facilities retired, net	$ 214

Regulatory Matters (Regulator_3

Regulatory Matters (Regulatory Matters Narrative - Duke Energy Florida) (Details) $ in Millions	Mar. 25, 2019USD ($)	Apr. 30, 2020USD ($)	Jan. 31, 2019USD ($)	Apr. 02, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 19, 2019USD ($)	Nov. 22, 2019USD ($)	Oct. 31, 2018customer
Hurricane Michael storm damage | Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Customers experiencing outages | customer									72,000
Estimated storm costs - capital and operation maintenance					$ 311
Amount of recovery costs sought								$ 191
Property, plant and equipment, net					106	$ 107
Hurricane Dorian storm damage | Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Estimated storm costs - capital and operation maintenance					147	167	$ 169
Noncurrent assets | Hurricane Michael storm damage | Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Estimated storm costs - capital and operation maintenance					$ 205	$ 204
Hamilton Project | 2017 Second Revised and Restated Stipulation and Settlement Agreement | FPSC | Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Approved rate increase (decrease), amount			$ 15
Trenton Generation Project | 2017 Second Revised and Restated Stipulation and Settlement Agreement | FPSC | Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Approved rate increase (decrease), amount	$ 13
Lake Placid Generation Project | 2017 Second Revised and Restated Stipulation and Settlement Agreement | FPSC | Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Approved rate increase (decrease), amount	8
DeBary Solar Project | 2017 Second Revised and Restated Stipulation and Settlement Agreement | FPSC | Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount	$ 11
Subsequent event | FPSC
Public Utilities, General Disclosures [Line Items]
Accelerated fuel cost refund				$ 78
Subsequent event | Columbia Project | 2017 Second Revised and Restated Stipulation and Settlement Agreement | FPSC | Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Approved rate increase (decrease), amount		$ 14

Regulatory Matters (Regulator_4

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

Apr. 27, 2020USD ($)

Jan. 31, 2020USD ($)

Sep. 03, 2019USD ($)MW

Apr. 13, 2018USD ($)

Sep. 27, 2017USD ($)

Sep. 26, 2017USD ($)

Mar. 31, 2017USD ($)

Dec. 31, 2015USD ($)

Mar. 31, 2020USD ($)

Mar. 31, 2019USD ($)

Dec. 31, 2017USD ($)

Jul. 12, 2019USD ($)

Dec. 31, 2018USD ($)

Sep. 28, 2018USD ($)

Public Utilities, General Disclosures [Line Items]

Regulated operating revenue, electric, non-nuclear

$ 5,124

$ 5,285

Duke Energy Ohio

Public Utilities, General Disclosures [Line Items]

Regulated operating revenue, electric, non-nuclear

346

$ 355

Ohio Base Rate Case 2017 | PUCO | Duke Energy Ohio

Public Utilities, General Disclosures [Line Items]

Requested rate increase (decrease), amount

$ 15

Requested return on equity, percent

10.40%

Requested rate increase (decrease), amended amount

$ (19)

Requested rate increase (decrease) amended, percentage

9.84%

Public utilities, requested equity capital structure, percentage

50.75%

Public utilities, requested debt capital structure, percentage

49.25%

Approved rate increase (decrease), amount

$ (20)

Energy Efficiency Cost Recovery | PUCO | Duke Energy Ohio

Public Utilities, General Disclosures [Line Items]

Regulated operating revenue, electric, non-nuclear

$ 20

MGP Cost Recovery - 2009 Through 2012 | PUCO | Duke Energy Ohio

Public Utilities, General Disclosures [Line Items]

Regulatory assets

55

MGP Cost Recovery - 2013 Through 2017 | PUCO | Duke Energy Ohio

Public Utilities, General Disclosures [Line Items]

Regulatory assets

$ 26

MGP Cost Recovery - 2018 | PUCO | Duke Energy Ohio

Public Utilities, General Disclosures [Line Items]

Regulatory assets

39

$ 20

Duke Energy Kentucky Electric base rate case | KPSC | Duke Energy Kentucky

Public Utilities, General Disclosures [Line Items]

Requested rate increase (decrease), amount

$ 46

Requested rate increase (decrease), amended amount

$ 44

Requested rate increase, percentage

12.50%

Distribution battery energy storage system (in MW) | MW

3.4

Approved return on equity percentage

9.25%

Duke Energy Kentucky Electric base rate case, Kentucky Attorney General | KPSC | Duke Energy Kentucky

Public Utilities, General Disclosures [Line Items]

Requested rate increase (decrease), amount

$ 26

Minimum | Ohio Base Rate Case 2017 | PUCO | Duke Energy Ohio

Public Utilities, General Disclosures [Line Items]

Requested rate increase (decrease), amount

$ (18)

Requested return on equity, percent

9.22%

Minimum | Natural Gas Pipeline extension | OPSB | Duke Energy Ohio

Public Utilities, General Disclosures [Line Items]

Estimated capital cost excluding AFUDC

163

Maximum | Ohio Base Rate Case 2017 | PUCO | Duke Energy Ohio

Public Utilities, General Disclosures [Line Items]

Requested rate increase (decrease), amount

$ (29)

Requested return on equity, percent

10.24%

Requested Rider Revenue Increase

$ 10

Maximum | Energy Efficiency Cost Recovery | PUCO | Duke Energy Ohio

Public Utilities, General Disclosures [Line Items]

Approved rate increase (decrease), amount

$ 38

Approved rate increase (decrease), one-time waiver amount

$ 56

Maximum | Natural Gas Pipeline extension | OPSB | Duke Energy Ohio

Public Utilities, General Disclosures [Line Items]

Estimated capital cost excluding AFUDC

$ 245

MGP Costs - regulatory disallowance | MGP Cost Recovery - 2013 Through 2017 | PUCO | Duke Energy Ohio

Public Utilities, General Disclosures [Line Items]

Regulatory assets

$ 12

MGP Costs - regulatory disallowance | MGP Cost Recovery - 2018 | PUCO | Duke Energy Ohio

Public Utilities, General Disclosures [Line Items]

Regulatory assets

$ 11

Subsequent event | Duke Energy Kentucky Electric base rate case | KPSC | Duke Energy Kentucky

Public Utilities, General Disclosures [Line Items]

Approved rate increase (decrease), amount

$ 24

Regulatory Matters (Regulator_5

Regulatory Matters (Regulatory Matters Narrative - Duke Energy Indiana) (Details) - Indiana rate case 2019 - IURC - Duke Energy Indiana - USD ($) $ in Millions	Dec. 04, 2019	Sep. 09, 2019	Jul. 02, 2019	Dec. 31, 2018
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount		$ 395	$ 395
Rate base				$ 10,200
Requested rate increase (decrease), amended amount	$ 396	393
Amount reduced from initial request		$ 2
Requested rate increase, percentage			15.00%
Requested rate increase, percentage, net of tax	15.60%		17.00%

Regulatory Matters (Regulator_6

Regulatory Matters (Regulatory Matters Narrative - Piedmont) (Details) - Piedmont Natural Gas - USD ($) $ in Millions	1 Months Ended
	Apr. 30, 2020	Nov. 30, 2019
Tennessee Integrity Management Rider Filing November 2018 | TPUC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount		$ 2
Subsequent event | North Carolina Integrity Management Rider Filing | NCUC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount	$ 15

Regulatory Matters (Other Regul

Regulatory Matters (Other Regulatory Matters) (Details) - USD ($) $ in Millions	Sep. 02, 2014	Mar. 31, 2020	Dec. 31, 2019
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net		$ 103,108	$ 102,127
Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net		32,650	32,397
Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net		22,815	$ 22,934
ACP
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage	47.00%
Long-term purchase commitment, period	20 years
Estimated capital cost		8,000
Investment amount		$ 1,200
Constitution
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage		24.00%
Dominion resources | ACP
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage		53.00%
Southern Company Gas | ACP
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage	5.00%
Williams Partners L.P. | Constitution
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage		41.00%
Financial guarantee | ACP
Public Utilities, General Disclosures [Line Items]
Maximum potential amount of future payments associated with guarantees		$ 845
Credit Facility | ACP
Public Utilities, General Disclosures [Line Items]
Percentage of outstanding borrowings		47.00%
Generation facilities evaluated for retirement | Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net		$ 707
Generation facilities evaluated for retirement | Duke Energy Progress
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net		$ 1,200

Regulatory Matters (Schedule of

Regulatory Matters (Schedule of Net Carrying Value Of Facilities and Megawatt Capacity) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020USD ($)MW	Dec. 31, 2019USD ($)
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	$ 103,108	$ 102,127
Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	32,650	32,397
Duke Energy Indiana
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	$ 11,132	$ 11,072
Generation facilities to be retired
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	5,002
Public utilities, property, plant and equipment, net	$ 2,939
Allen Steam Station Units 1-3 | Generation facilities to be retired | Duke Energy Carolinas
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	585
Public utilities, property, plant and equipment, net	$ 149
Gallagher Units 2 and 4 | Generation facilities to be retired | Duke Energy Indiana
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	280
Public utilities, property, plant and equipment, net	$ 118
Gibson Units 1-5 | Generation facilities to be retired | Duke Energy Indiana
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	3,132
Public utilities, property, plant and equipment, net	$ 1,708
Cayuga Units 1-2 | Generation facilities to be retired | Duke Energy Indiana
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	1,005
Public utilities, property, plant and equipment, net	$ 964

Commitments and Contingencies_2

Commitments and Contingencies (Schedule of Environmental Loss Contingencies) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020USD ($)
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at beginning of period	$ 58
Provisions/adjustments	3
Cash reductions	(3)
Balance at end of period	58
Environmental exit costs, reasonably possible additional loss	58
Duke Energy Carolinas
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at beginning of period	11
Cash reductions	(1)
Balance at end of period	10
Environmental exit costs, reasonably possible additional loss	11
Progress Energy
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at beginning of period	16
Cash reductions	(1)
Balance at end of period	15
Duke Energy Progress
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at beginning of period	4
Provisions/adjustments	1
Cash reductions	0
Balance at end of period	5
Duke Energy Florida
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at beginning of period	9
Cash reductions	0
Balance at end of period	9
Duke Energy Ohio
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at beginning of period	19
Provisions/adjustments	1
Cash reductions	(1)
Balance at end of period	19
Environmental exit costs, reasonably possible additional loss	41
Duke Energy Indiana
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at beginning of period	4
Provisions/adjustments	1
Cash reductions	0
Balance at end of period	5
Piedmont Natural Gas
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at beginning of period	8
Cash reductions	0
Balance at end of period	8
Environmental exit costs, reasonably possible additional loss	$ 2

Commitments and Contingencies_3

Commitments and Contingencies (Narrative) (Details) $ in Millions	Jun. 18, 2018USD ($)	Mar. 31, 2020USD ($)plantclaim	Jan. 01, 2020USD ($)	Dec. 31, 2019USD ($)
ASU 2016-13
Loss Contingencies [Line Items]
Reserve for credit losses for financial guarantees			$ 99
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		$ 596		$ 604
Reinsurance retention policy, excess retention, amount reinsured		747
Probable insurance recoveries		$ 742		$ 742
Duke Energy Carolinas | Asbestos-related Injuries and Damages Claims | Non-malignant cases
Loss Contingencies [Line Items]
Loss contingency, pending claims, number | claim		118
Asbestos-related injuries and damages reserves		$ 30
Duke Energy Carolinas | Asbestos-related Injuries and Damages Claims | Malignant cases
Loss Contingencies [Line Items]
Loss contingency, pending claims, number | claim		51
Asbestos-related injuries and damages reserves		$ 17
Duke Energy Progress | Spent Nuclear Fuel Matters
Loss Contingencies [Line Items]
Pending litigation, damages sought	$ 100
Duke Energy Florida | Spent Nuclear Fuel Matters
Loss Contingencies [Line Items]
Pending litigation, damages sought	$ 203
Duke Energy and Duke Energy Carolinas | ASU 2016-13
Loss Contingencies [Line Items]
Reserve for credit losses for insurance receivables			$ 15

Commitments and Contingencies_4

Commitments and Contingencies (Schedule of Legal Reserves) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Loss Contingencies [Line Items]
Reserves for legal matters	$ 61	$ 62
Duke Energy Carolinas
Loss Contingencies [Line Items]
Reserves for legal matters	3	2
Progress Energy
Loss Contingencies [Line Items]
Reserves for legal matters	52	55
Duke Energy Progress
Loss Contingencies [Line Items]
Reserves for legal matters	9	12
Duke Energy Florida
Loss Contingencies [Line Items]
Reserves for legal matters	23	22
Piedmont Natural Gas
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, 2020	Mar. 31, 2019
Debt Instrument [Line Items]
Debt issuances	$ 3,138,000,000
Repayments of long-term debt	292,000,000	$ 1,201,000,000
Duke Energy Carolinas
Debt Instrument [Line Items]
Debt issuances	900,000,000
Repayments of long-term debt	2,000,000	1,000,000
Duke Energy Carolinas | First Mortgage Bonds
Debt Instrument [Line Items]
Repayments of long-term debt	450,000,000
Duke Energy Indiana
Debt Instrument [Line Items]
Debt issuances	550,000,000
Repayments of long-term debt		$ 60,000,000
Duke Energy Indiana | First Mortgage Bonds
Debt Instrument [Line Items]
Repayments of long-term debt	$ 500,000,000
Unsecured Debt | March 2020 1.400% Due March 2021
Debt Instrument [Line Items]
Interest Rate	1.40%
Debt issuances	$ 1,688,000,000
First Mortgage Bonds | January 2020 2.450% Due 2030
Debt Instrument [Line Items]
Interest Rate	2.45%
Debt issuances	$ 500,000,000
First Mortgage Bonds | January 2020 3.20% Due 2049
Debt Instrument [Line Items]
Interest Rate	3.20%
Debt issuances	$ 400,000,000
First Mortgage Bonds | March 2020 2.750% Due 2050
Debt Instrument [Line Items]
Interest Rate	2.75%
Debt issuances	$ 550,000,000
First Mortgage Bonds | Duke Energy Carolinas | January 2020 2.450% Due 2030
Debt Instrument [Line Items]
Debt issuances	500,000,000
First Mortgage Bonds | Duke Energy Carolinas | January 2020 3.20% Due 2049
Debt Instrument [Line Items]
Debt issuances	400,000,000
First Mortgage Bonds | Duke Energy Indiana | March 2020 2.750% Due 2050
Debt Instrument [Line Items]
Debt issuances	550,000,000
Duke Energy (Parent) | Duke Energy (Parent)
Debt Instrument [Line Items]
Debt issuances	1,688,000,000
Duke Energy (Parent) | Unsecured Debt | Duke Energy (Parent) | March 2020 1.400% Due March 2021
Debt Instrument [Line Items]
Debt issuances	$ 1,688,000,000

Debt and Credit Facilities (S_2

Debt and Credit Facilities (Summary of Current Maturities of Long-term Debt) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 5,077	$ 3,141
Other debt obligations
Debt Instrument [Line Items]
Current maturities of long-term debt	359
Duke Energy Progress
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 1,006	1,006
Duke Energy Progress | Unsecured Debt | Debt maturing December 2020, floating interest rate
Debt Instrument [Line Items]
Interest Rate	2.292%
Current maturities of long-term debt	$ 700
Duke Energy Progress | First Mortgage Bonds | Bonds maturing September 2020, floating interest rate
Debt Instrument [Line Items]
Interest Rate	1.076%
Current maturities of long-term debt	$ 300
Progress Energy
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 1,828	1,577
Progress Energy | Unsecured Debt | Debt maturing January 2021, 4.400% interest rate
Debt Instrument [Line Items]
Interest Rate	4.40%
Current maturities of long-term debt	$ 500
Duke Energy Florida
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 322	571
Duke Energy Florida | First Mortgage Bonds | Bonds maturing April 2020, 4.550% interest rate
Debt Instrument [Line Items]
Interest Rate	4.55%
Current maturities of long-term debt	$ 250
Duke Energy Carolinas
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 457	458
Duke Energy Carolinas | First Mortgage Bonds | Bonds maturing June 2020, 4.300% interest rate
Debt Instrument [Line Items]
Interest Rate	4.30%
Current maturities of long-term debt	$ 450
Duke Energy Indiana
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 503	$ 503
Duke Energy Indiana | First Mortgage Bonds | Bonds maturing July 2020, 3.750% interest rate
Debt Instrument [Line Items]
Interest Rate	3.75%
Current maturities of long-term debt	$ 500
Duke Energy (Parent) | Unsecured Debt | Debt maturing June 2020, 2.100% interest rate
Debt Instrument [Line Items]
Interest Rate	2.10%
Current maturities of long-term debt	$ 330
Duke Energy (Parent) | Unsecured Debt | Debt maturing March 2021, floating interest rate
Debt Instrument [Line Items]
Interest Rate	1.40%
Current maturities of long-term debt	$ 1,688

Debt and Credit Facilities (Nar

Debt and Credit Facilities (Narrative) (Details) - Master Credit Facility	Mar. 31, 2020USD ($)
Debt Instrument [Line Items]
Facility size	$ 8,000,000,000
Duke Energy Carolinas
Debt Instrument [Line Items]
Facility size	1,500,000,000
Duke Energy Carolinas | USDOJ | North Carolina ash basins
Debt Instrument [Line Items]
Minimum master credit facility balance required	$ 250,000,000

Debt and Credit Facilities (Sch

Debt and Credit Facilities (Schedule of Line of Credit Facilities) (Details) - Master Credit Facility	Mar. 31, 2020USD ($)
Line of Credit Facility [Line Items]
Facility size	$ 8,000,000,000
Commercial paper	(2,540,000,000)
Outstanding letters of credit	(49,000,000)
Tax-exempt bonds	(81,000,000)
Coal ash set-aside	(500,000,000)
Available capacity under the Master Credit Facility	4,830,000,000
Duke Energy Carolinas
Line of Credit Facility [Line Items]
Facility size	1,500,000,000
Commercial paper	(300,000,000)
Outstanding letters of credit	(4,000,000)
Coal ash set-aside	(250,000,000)
Available capacity under the Master Credit Facility	946,000,000
Duke Energy Progress
Line of Credit Facility [Line Items]
Facility size	1,250,000,000
Commercial paper	(275,000,000)
Outstanding letters of credit	(2,000,000)
Coal ash set-aside	(250,000,000)
Available capacity under the Master Credit Facility	723,000,000
Duke Energy Florida
Line of Credit Facility [Line Items]
Facility size	800,000,000
Commercial paper	(167,000,000)
Available capacity under the Master Credit Facility	633,000,000
Duke Energy Ohio
Line of Credit Facility [Line Items]
Facility size	600,000,000
Commercial paper	(243,000,000)
Available capacity under the Master Credit Facility	357,000,000
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 Natural Gas
Line of Credit Facility [Line Items]
Facility size	600,000,000
Commercial paper	(265,000,000)
Outstanding letters of credit	(1,000,000)
Available capacity under the Master Credit Facility	334,000,000
Duke Energy (Parent)
Line of Credit Facility [Line Items]
Facility size	2,650,000,000
Commercial paper	(1,140,000,000)
Outstanding letters of credit	(42,000,000)
Available capacity under the Master Credit Facility	1,468,000,000
Duke Energy (Parent) | Proceeds loaned to subsidiary registrants
Line of Credit Facility [Line Items]
Commercial paper	$ (625,000,000)

Debt and Credit Facilities (S_3

Debt and Credit Facilities (Schedule of Other Credit Facilities) (Details)	1 Months Ended	3 Months Ended
	Mar. 31, 2020USD ($)	Mar. 31, 2020USD ($)
Master Credit Facility
Line of Credit Facility [Line Items]
Facility size	$ 8,000,000,000	$ 8,000,000,000
Duke Energy Progress | Master Credit Facility
Line of Credit Facility [Line Items]
Facility size	1,250,000,000	1,250,000,000
Duke Energy Progress | Term Loan Facility
Line of Credit Facility [Line Items]
Facility size	700,000,000	700,000,000
Amount drawn	700,000,000	$ 700,000,000
Duke Energy (Parent) Three-Year Revolving Credit Facility | Master Credit Facility
Line of Credit Facility [Line Items]
Facility Term		3 years
Facility size	1,000,000,000	$ 1,000,000,000
Amount drawn	1,000,000,000	$ 1,000,000,000
Additional amount drawn	$ 500,000,000

Goodwill (Rollforward of Goodwi

Goodwill (Rollforward of Goodwill) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
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
Goodwill, adjusted for accumulated impairment charges	17,379	17,379
Gas Utilities and Infrastructure
Goodwill [Line Items]
Goodwill balance	1,924	1,924
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 (Narrative) (Details)

Goodwill (Narrative) (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
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
Gas Utilities and Infrastructure
Goodwill [Line Items]
Goodwill	1,924,000,000	1,924,000,000
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
Accumulated impairment charges	0	0
Piedmont Natural Gas
Goodwill [Line Items]
Goodwill	49,000,000	49,000,000
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, 2020	Mar. 31, 2019
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	$ 134	$ 212
Duke Energy Carolinas | Indemnification coverages | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	5	5
Duke Energy Carolinas | JDA | Duke Energy Progress
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	24	93
Related party transaction, other revenues from transactions with related party	7	23
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	6	4
Progress Energy | Corporate governance and shared service expenses | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	146	176
Progress Energy | Indemnification coverages | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	9	9
Progress Energy | JDA | Duke Energy Carolinas
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	7	23
Related party transaction, other revenues from transactions with related party	24	93
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	75	106
Duke Energy Progress | Indemnification coverages | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	4	4
Duke Energy Progress | JDA | Duke Energy Carolinas
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	7	23
Related party transaction, other revenues from transactions with related party	24	93
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	71	70
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	84	85
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	106	97
Duke Energy Indiana | Indemnification coverages | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	2	2
Piedmont Natural Gas | Corporate governance and shared service expenses | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	34	32
Piedmont Natural Gas | Indemnification coverages | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	1	1
Piedmont Natural Gas | Intercompany natural gas purchases and sales | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	25	23
Piedmont Natural Gas | Natural gas storage and transportation costs | Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$ 6	$ 5

Related Party Transactions (Int

Related Party Transactions (Intercompany Income Taxes) (Details) - Affiliated Entity - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Duke Energy Carolinas
Related Party Transaction [Line Items]
Income tax payable	$ 44	$ 5
Progress Energy
Related Party Transaction [Line Items]
Income taxes receivable	114	125
Duke Energy Progress
Related Party Transaction [Line Items]
Income taxes receivable	1	28
Duke Energy Florida
Related Party Transaction [Line Items]
Income taxes receivable	4
Income tax payable		2
Duke Energy Ohio
Related Party Transaction [Line Items]
Income taxes receivable		9
Duke Energy Indiana
Related Party Transaction [Line Items]
Income taxes receivable		28
Income tax payable	6
Piedmont Natural Gas
Related Party Transaction [Line Items]
Income taxes receivable		$ 13
Income tax payable	$ 10

Derivatives and Hedging (Notion

Derivatives and Hedging (Notional Amounts of Derivative Instruments) (Details) Mcf in Millions, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2020USD ($)GWhMcf	Dec. 31, 2019USD ($)GWhMcf
Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 3,018	$ 2,270
Commodity contracts | Electricity (GWh)
Derivative [Line Items]
Notional amount, energy measure (in gigawatt-hours) | GWh	6,737	15,858
Commodity contracts | Natural gas (millions of dekatherms)
Derivative [Line Items]
Notional amount, volume (in millions of decatherms) | Mcf	709	704
Designated contracts | Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 991	$ 993
Undesignated contracts | Interest Rate Contracts
Derivative [Line Items]
Notional amount	2,027	1,277
VIE primary beneficiary | Designated contracts | Interest Rate Contracts
Derivative [Line Items]
Notional amount	691	693
Duke Energy Carolinas | Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 400	$ 450
Duke Energy Carolinas | Commodity contracts | Natural gas (millions of dekatherms)
Derivative [Line Items]
Notional amount, volume (in millions of decatherms) | Mcf	145	130
Duke Energy Carolinas | Undesignated contracts | Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 400	$ 450
Progress Energy | Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 1,600	$ 800
Progress Energy | Commodity contracts | Natural gas (millions of dekatherms)
Derivative [Line Items]
Notional amount, volume (in millions of decatherms) | Mcf	158	160
Progress Energy | Undesignated contracts | Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 1,600	$ 800
Duke Energy Progress | Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 1,050	$ 250
Duke Energy Progress | Commodity contracts | Natural gas (millions of dekatherms)
Derivative [Line Items]
Notional amount, volume (in millions of decatherms) | Mcf	158	160
Duke Energy Progress | Undesignated contracts | Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 1,050	$ 250
Duke Energy Florida | Interest Rate Contracts
Derivative [Line Items]
Notional amount	550	550
Duke Energy Florida | Undesignated contracts | Interest Rate Contracts
Derivative [Line Items]
Notional amount	550	550
Duke Energy Ohio | Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 27	$ 27
Duke Energy Ohio | Commodity contracts | Electricity (GWh)
Derivative [Line Items]
Notional amount, energy measure (in gigawatt-hours) | GWh	977	1,887
Duke Energy Ohio | Undesignated contracts | Interest Rate Contracts
Derivative [Line Items]
Notional amount	$ 27	$ 27
Duke Energy Indiana | Commodity contracts | Electricity (GWh)
Derivative [Line Items]
Notional amount, energy measure (in gigawatt-hours) | GWh	5,760	13,971
Duke Energy Indiana | Commodity contracts | Natural gas (millions of dekatherms)
Derivative [Line Items]
Notional amount, volume (in millions of decatherms) | Mcf	4	3
Piedmont Natural Gas | Commodity contracts | Natural gas (millions of dekatherms)
Derivative [Line Items]
Notional amount, volume (in millions of decatherms) | Mcf	402	411

Derivatives and Hedging (Narrat

Derivatives and Hedging (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended
	Apr. 30, 2020	Mar. 31, 2020
Call option
Derivative [Line Items]
Aggregate notional amount		305,000
Put option
Derivative [Line Items]
Aggregate notional amount		305,000
Not Designated as Hedging Instruments | Duke Energy Florida | Equity Securities Contracts | Subsequent event
Derivative [Line Items]
Proceeds liquidation of options	$ 7

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, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	$ 34	$ 25
Location and fair value amounts of derivatives (Liability)	390	300
Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	9	24
Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	25	1
Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	178	118
Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	212	182
Commodity Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	10	18
Location and fair value amounts of derivatives (Liability)	209	223
Interest Rate Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	4	6
Location and fair value amounts of derivatives (Liability)	181	53
Equity Securities Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	20	1
Location and fair value amounts of derivatives (Liability)		24
Not Designated as Hedging Instruments | Commodity Contracts | Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	6	17
Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	4	1
Not Designated as Hedging Instruments | Commodity Contracts | Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	79	67
Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	130	156
Not Designated as Hedging Instruments | Interest Rate Contracts | Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3	6
Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1
Not Designated as Hedging Instruments | Interest Rate Contracts | Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	30	8
Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	28	5
Not Designated as Hedging Instruments | Equity Securities Contracts | Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		1
Not Designated as Hedging Instruments | Equity Securities Contracts | Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	20
Not Designated as Hedging Instruments | Equity Securities Contracts | Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		24
Designated as Hedging Instruments | Interest Rate Contracts | Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	69	19
Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	54	21
Duke Energy Carolinas
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2
Location and fair value amounts of derivatives (Liability)	74	49
Duke Energy Carolinas | Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2
Duke Energy Carolinas | Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	40	39
Duke Energy Carolinas | Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	34	10
Duke Energy Carolinas | Commodity Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2
Location and fair value amounts of derivatives (Liability)	51	43
Duke Energy Carolinas | Interest Rate Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	23	6
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)	2
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)	40	33
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)	11	10
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)		6
Duke Energy Carolinas | Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	23
Progress Energy
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	25	7
Location and fair value amounts of derivatives (Liability)	95	88
Progress Energy | Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3	7
Progress Energy | Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	22
Progress Energy | Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	60	51
Progress Energy | Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	35	37
Progress Energy | Commodity Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1
Location and fair value amounts of derivatives (Liability)	66	63
Progress Energy | Interest Rate Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	4	6
Location and fair value amounts of derivatives (Liability)	29	1
Progress Energy | Equity Securities Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	20	1
Location and fair value amounts of derivatives (Liability)		24
Progress Energy | Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1
Progress Energy | Not Designated as Hedging Instruments | Commodity Contracts | Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	31	26
Progress Energy | Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	35	37
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)	3	6
Progress Energy | Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1
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)	29	1
Progress Energy | Not Designated as Hedging Instruments | Equity Securities Contracts | Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		1
Progress Energy | Not Designated as Hedging Instruments | Equity Securities Contracts | Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	20
Progress Energy | Not Designated as Hedging Instruments | Equity Securities Contracts | Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		24
Duke Energy Progress
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	5
Location and fair value amounts of derivatives (Liability)	51	49
Duke Energy Progress | Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3
Duke Energy Progress | Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2
Duke Energy Progress | Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	31	27
Duke Energy Progress | Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	20	22
Duke Energy Progress | Commodity Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1
Location and fair value amounts of derivatives (Liability)	51	48
Duke Energy Progress | Interest Rate Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	4
Location and fair value amounts of derivatives (Liability)		1
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)	1
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)	31	26
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)	20	22
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)	3
Duke Energy Progress | Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1
Duke Energy Progress | Not Designated as Hedging Instruments | Interest Rate Contracts | Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		1
Duke Energy Florida
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	20	7
Location and fair value amounts of derivatives (Liability)	29	24
Duke Energy Florida | Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		7
Duke Energy Florida | Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	20
Duke Energy Florida | Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	29	24
Duke Energy Florida | Interest Rate Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		6
Location and fair value amounts of derivatives (Liability)	29
Duke Energy Florida | Equity Securities Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	20	1
Location and fair value amounts of derivatives (Liability)		24
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)		6
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)	29
Duke Energy Florida | Not Designated as Hedging Instruments | Equity Securities Contracts | Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		1
Duke Energy Florida | Not Designated as Hedging Instruments | Equity Securities Contracts | Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	20
Duke Energy Florida | Not Designated as Hedging Instruments | Equity Securities Contracts | Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		24
Duke Energy Ohio
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	4
Location and fair value amounts of derivatives (Liability)	7	6
Duke Energy Ohio | Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		3
Duke Energy Ohio | Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	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)	6	5
Duke Energy Ohio | Commodity Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	4
Duke Energy Ohio | Interest Rate Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	7	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)		3
Duke Energy Ohio | Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	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)	6	5
Duke Energy Indiana
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	13
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	13
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	13
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	13
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 Natural Gas
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3	1
Location and fair value amounts of derivatives (Liability)	91	117
Piedmont Natural Gas | Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3	1
Piedmont Natural Gas | Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	8	7
Piedmont Natural Gas | Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	83	110
Piedmont Natural Gas | Commodity Contracts
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3	1
Location and fair value amounts of derivatives (Liability)	91	117
Piedmont Natural Gas | Not Designated as Hedging Instruments | Commodity Contracts | Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3	1
Piedmont Natural Gas | Not Designated as Hedging Instruments | Commodity Contracts | Current liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	8	7
Piedmont Natural Gas | Not Designated as Hedging Instruments | Commodity Contracts | Noncurrent liabilities
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	83	110
Piedmont Natural Gas | Not Designated as Hedging Instruments | Interest Rate Contracts | Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	0
Piedmont Natural Gas | Not Designated as Hedging Instruments | Equity Securities Contracts | Current assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		$ 0
Piedmont Natural Gas | Not Designated as Hedging Instruments | Equity Securities Contracts | Noncurrent assets
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	$ 0

Derivatives and Hedging (Schedu

Derivatives and Hedging (Schedule of Offsetting Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	$ 34	$ 25
Net amounts recognized on the Condensed Consolidated Balance Sheet	34	25
Current assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	9	24
Gross amounts offset		(1)
Net amounts recognized on the Condensed Consolidated Balance Sheet	9	23
Noncurrent assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	25	1
Gross amounts offset	(3)
Net amounts recognized on the Condensed Consolidated Balance Sheet	2	1
Net amounts presented in NDTF
Offsetting Derivative Assets [Abstract]
Net amounts recognized on the Condensed Consolidated Balance Sheet	20
Duke Energy Carolinas
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	2
Net amounts recognized on the Condensed Consolidated Balance Sheet	2
Duke Energy Carolinas | Noncurrent assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	2
Gross amounts offset	(2)
Progress Energy
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	25	7
Net amounts recognized on the Condensed Consolidated Balance Sheet	25	7
Progress Energy | Current assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	3	7
Gross amounts offset		(1)
Net amounts recognized on the Condensed Consolidated Balance Sheet	3	6
Progress Energy | Noncurrent assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	22
Gross amounts offset	(1)
Net amounts recognized on the Condensed Consolidated Balance Sheet	1
Progress Energy | Net amounts presented in NDTF
Offsetting Derivative Assets [Abstract]
Net amounts recognized on the Condensed Consolidated Balance Sheet	20
Duke Energy Progress
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	5
Net amounts recognized on the Condensed Consolidated Balance Sheet	5
Duke Energy Progress | Current assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	3
Net amounts recognized on the Condensed Consolidated Balance Sheet	3
Duke Energy Progress | Noncurrent assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	2
Gross amounts offset	(1)
Net amounts recognized on the Condensed Consolidated Balance Sheet	1
Duke Energy Florida
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	20	7
Net amounts recognized on the Condensed Consolidated Balance Sheet		7
Duke Energy Florida | Current assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized		7
Gross amounts offset		(1)
Net amounts recognized on the Condensed Consolidated Balance Sheet		6
Duke Energy Florida | Noncurrent assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	20
Duke Energy Florida | Net amounts presented in NDTF
Offsetting Derivative Assets [Abstract]
Net amounts recognized on the Condensed Consolidated Balance Sheet	20
Duke Energy Ohio
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	1	4
Duke Energy Ohio | Current assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized		3
Net amounts recognized on the Condensed Consolidated Balance Sheet		3
Duke Energy Ohio | Noncurrent assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	1	1
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	1
Duke Energy Indiana
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	2	13
Net amounts recognized on the Condensed Consolidated Balance Sheet	2	13
Duke Energy Indiana | Current assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	2	13
Net amounts recognized on the Condensed Consolidated Balance Sheet	2	13
Piedmont Natural Gas
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	3	1
Net amounts recognized on the Condensed Consolidated Balance Sheet	3	1
Piedmont Natural Gas | Current assets
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	3	1
Net amounts recognized on the Condensed Consolidated Balance Sheet	$ 3	$ 1

Derivatives and Hedging (Sche_2

Derivatives and Hedging (Schedule of Offsetting Liabilities) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	$ 390	$ 300
Net amounts recognized on the Condensed Consolidated Balance Sheet	390	277
Current liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	178	118
Gross amounts offset		(24)
Net amounts recognized on the Condensed Consolidated Balance Sheet	178	94
Noncurrent liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	212	182
Gross amounts offset	(3)
Net amounts recognized on the Condensed Consolidated Balance Sheet	209	182
Duke Energy Carolinas
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	74	49
Net amounts recognized on the Condensed Consolidated Balance Sheet	74	49
Duke Energy Carolinas | Current liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	40	39
Net amounts recognized on the Condensed Consolidated Balance Sheet	40	39
Duke Energy Carolinas | Noncurrent liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	34	10
Gross amounts offset	(2)
Net amounts recognized on the Condensed Consolidated Balance Sheet	32	10
Progress Energy
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	95	88
Net amounts recognized on the Condensed Consolidated Balance Sheet	95	65
Progress Energy | Current liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	60	51
Gross amounts offset		(24)
Net amounts recognized on the Condensed Consolidated Balance Sheet	60	27
Progress Energy | Noncurrent liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	35	37
Gross amounts offset	(1)
Net amounts recognized on the Condensed Consolidated Balance Sheet	34	37
Duke Energy Progress
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	51	49
Net amounts recognized on the Condensed Consolidated Balance Sheet	51	49
Duke Energy Progress | Current liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	31	27
Net amounts recognized on the Condensed Consolidated Balance Sheet	31	27
Duke Energy Progress | Noncurrent liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	20	22
Gross amounts offset	(1)
Net amounts recognized on the Condensed Consolidated Balance Sheet	19	22
Duke Energy Florida
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	29	24
Net amounts recognized on the Condensed Consolidated Balance Sheet	29	1
Duke Energy Florida | Current liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	29	24
Gross amounts offset		(24)
Net amounts recognized on the Condensed Consolidated Balance Sheet	29
Duke Energy Ohio
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	7	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	6	5
Net amounts recognized on the Condensed Consolidated Balance Sheet	6	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 Natural Gas
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	91	117
Net amounts recognized on the Condensed Consolidated Balance Sheet	91	117
Piedmont Natural Gas | Current liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	8	7
Net amounts recognized on the Condensed Consolidated Balance Sheet	8	7
Piedmont Natural Gas | Noncurrent liabilities
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	83	110
Net amounts recognized on the Condensed Consolidated Balance Sheet	$ 83	$ 110

Derivatives and Hedging (Deriva

Derivatives and Hedging (Derivative Instruments with Credit-Risk Related Contingent Features and Cash Collateral) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Schedule of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value of derivatives in a net liability position	$ 96	$ 79
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	96	79
Duke Energy Carolinas
Schedule of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value of derivatives in a net liability position	45	35
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	45	35
Progress Energy
Schedule of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value of derivatives in a net liability position	51	44
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	51	44
Duke Energy Progress
Schedule of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value of derivatives in a net liability position	51	44
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	$ 51	$ 44

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, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale
Estimated Fair Value	$ 2,711
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	2,671	$ 3,675
Unrealized Holding Losses	193	57
Estimated Fair Value	7,511	8,562
NDTF
Available-for-sale Securities
Cash and cash equivalents	119	101
Equity Securities, FV-NI
Equity Securities, FV-NI, Accumulated Unrealized Gain	2,499	3,523
Equity Securities, FV-NI, Accumulated Unrealized Loss	170	55
Equity securities, FV-NI	4,488	5,661
Debt Securities, Available-for-sale
Estimated Fair Value	2,540	2,469
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	2,629	3,609
Unrealized Holding Losses	191	57
Estimated Fair Value	7,048	8,130
Other Investments
Available-for-sale Securities
Cash and cash equivalents	78	52
Equity Securities, FV-NI
Equity Securities, FV-NI, Accumulated Unrealized Gain	31	57
Equity Securities, FV-NI, Accumulated Unrealized Loss	1
Equity securities, FV-NI	95	122
Debt Securities, Available-for-sale
Estimated Fair Value	368	310
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	42	66
Unrealized Holding Losses	2
Estimated Fair Value	463	432
Duke Energy Carolinas
Debt Securities, Available-for-sale
Estimated Fair Value	1,181
Duke Energy Carolinas | NDTF
Available-for-sale Securities
Cash and cash equivalents	33	21
Equity Securities, FV-NI
Equity Securities, FV-NI, Accumulated Unrealized Gain	1,355	1,914
Equity Securities, FV-NI, Accumulated Unrealized Loss	81	8
Equity securities, FV-NI	2,498	3,154
Debt Securities, Available-for-sale
Estimated Fair Value	1,214	1,193
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	1,411	1,957
Unrealized Holding Losses	97	10
Estimated Fair Value	3,712	4,347
Progress Energy
Debt Securities, Available-for-sale
Estimated Fair Value	1,293
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	1,223	1,655
Unrealized Holding Losses	94	47
Estimated Fair Value	3,458	3,883
Progress Energy | NDTF
Available-for-sale Securities
Cash and cash equivalents	86	80
Equity Securities, FV-NI
Equity Securities, FV-NI, Accumulated Unrealized Gain	1,144	1,609
Equity Securities, FV-NI, Accumulated Unrealized Loss	89	47
Equity securities, FV-NI	1,990	2,507
Debt Securities, Available-for-sale
Estimated Fair Value	1,326	1,276
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	1,218	1,652
Unrealized Holding Losses	94	47
Estimated Fair Value	3,336	3,783
Progress Energy | Other Investments
Available-for-sale Securities
Cash and cash equivalents	69	49
Debt Securities, Available-for-sale
Estimated Fair Value	122	100
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	5	3
Estimated Fair Value	122	100
Duke Energy Progress
Debt Securities, Available-for-sale
Estimated Fair Value	966
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	934	1,300
Unrealized Holding Losses	84	21
Estimated Fair Value	2,650	3,053
Duke Energy Progress | NDTF
Available-for-sale Securities
Cash and cash equivalents	51	53
Equity Securities, FV-NI
Equity Securities, FV-NI, Accumulated Unrealized Gain	881	1,258
Equity Securities, FV-NI, Accumulated Unrealized Loss	79	21
Equity securities, FV-NI	1,631	2,077
Debt Securities, Available-for-sale
Estimated Fair Value	1,017	974
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	934	1,300
Unrealized Holding Losses	84	21
Estimated Fair Value	2,648	3,051
Duke Energy Progress | Other Investments
Available-for-sale Securities
Cash and cash equivalents	2	2
Debt Securities, Available-for-sale
Estimated Fair Value	2	2
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Estimated Fair Value	2	2
Duke Energy Florida
Debt Securities, Available-for-sale
Estimated Fair Value	327
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	289	355
Unrealized Holding Losses	10	26
Estimated Fair Value	744	787
Duke Energy Florida | NDTF
Available-for-sale Securities
Cash and cash equivalents	35	27
Equity Securities, FV-NI
Equity Securities, FV-NI, Accumulated Unrealized Gain	263	351
Equity Securities, FV-NI, Accumulated Unrealized Loss	10	26
Equity securities, FV-NI	359	430
Debt Securities, Available-for-sale
Estimated Fair Value	309	302
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	284	352
Unrealized Holding Losses	10	26
Estimated Fair Value	688	732
Duke Energy Florida | Other Investments
Available-for-sale Securities
Cash and cash equivalents	3	4
Debt Securities, Available-for-sale
Estimated Fair Value	56	55
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	5	3
Estimated Fair Value	56	55
Duke Energy Indiana
Equity Securities, FV-NI
Equity Securities, FV-NI, Accumulated Unrealized Gain	26	43
Equity Securities, FV-NI, Accumulated Unrealized Loss	1
Equity securities, FV-NI	63	81
Debt Securities, Available-for-sale
Estimated Fair Value	43
Investments, Accumulated Gross Unrealized Gains (Losses) [Abstract]
Unrealized Holding Gains	27	44
Unrealized Holding Losses	2
Estimated Fair Value	106	125
Duke Energy Indiana | Other Investments
Equity Securities, FV-NI
Equity securities, FV-NI	63	81
Corporate debt securities | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	26	37
Gross Unrealized Holding Losses	16	1
Estimated Fair Value	642	603
Corporate debt securities | Other Investments
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains		3
Estimated Fair Value	89	67
Corporate debt securities | Duke Energy Carolinas | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	15	21
Gross Unrealized Holding Losses	12	1
Estimated Fair Value	392	361
Corporate debt securities | Progress Energy | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	11	16
Gross Unrealized Holding Losses	4
Estimated Fair Value	250	242
Corporate debt securities | Duke Energy Progress | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	11	16
Gross Unrealized Holding Losses	4
Estimated Fair Value	250	242
Corporate debt securities | Duke Energy Indiana
Debt Securities, Available-for-sale
Estimated Fair Value	4	6
Municipal bonds | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	10	13
Gross Unrealized Holding Losses	2
Estimated Fair Value	404	368
Municipal bonds | Other Investments
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	6	4
Gross Unrealized Holding Losses	1
Estimated Fair Value	98	94
Municipal bonds | Duke Energy Carolinas | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	3	3
Gross Unrealized Holding Losses	1
Estimated Fair Value	128	96
Municipal bonds | Progress Energy | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	7	10
Gross Unrealized Holding Losses	1
Estimated Fair Value	276	272
Municipal bonds | Progress Energy | Other Investments
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	5	3
Estimated Fair Value	53	51
Municipal bonds | Duke Energy Progress | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	7	10
Gross Unrealized Holding Losses	1
Estimated Fair Value	276	272
Municipal bonds | Duke Energy Florida | Other Investments
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	5	3
Estimated Fair Value	53	51
Municipal bonds | Duke Energy Indiana
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	1	1
Gross Unrealized Holding Losses	1
Estimated Fair Value	36	36
U.S. government bonds | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	70	33
Gross Unrealized Holding Losses		1
Estimated Fair Value	1,212	1,256
U.S. government bonds | Other Investments
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	5	2
Estimated Fair Value	51	41
U.S. government bonds | Duke Energy Carolinas | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	35	16
Gross Unrealized Holding Losses		1
Estimated Fair Value	502	578
U.S. government bonds | Progress Energy | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	35	17
Estimated Fair Value	710	678
U.S. government bonds | Duke Energy Progress | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	34	16
Estimated Fair Value	436	403
U.S. government bonds | Duke Energy Florida | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	1	1
Estimated Fair Value	274	275
U.S. government bonds | Duke Energy Indiana
Debt Securities, Available-for-sale
Estimated Fair Value	3	2
NDTF equity security contracts | NDTF
Equity Securities, FV-NI
Equity Securities, FV-NI, Accumulated Unrealized Gain	20
Equity securities, FV-NI	20
NDTF equity security contracts | Progress Energy | NDTF
Equity Securities, FV-NI
Equity Securities, FV-NI, Accumulated Unrealized Gain	20
Equity securities, FV-NI	20
NDTF equity security contracts | Duke Energy Florida | NDTF
Equity Securities, FV-NI
Equity Securities, FV-NI, Accumulated Unrealized Gain	20
Equity securities, FV-NI	20
Other debt securities | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	4	3
Gross Unrealized Holding Losses	3
Estimated Fair Value	163	141
Other debt securities | Other Investments
Debt Securities, Available-for-sale
Estimated Fair Value	52	56
Other debt securities | Duke Energy Carolinas | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	3	3
Gross Unrealized Holding Losses	3
Estimated Fair Value	159	137
Other debt securities | Progress Energy | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	1
Estimated Fair Value	4	4
Other debt securities | Duke Energy Progress | NDTF
Debt Securities, Available-for-sale
Gross Unrealized Holding Gains	1
Estimated Fair Value	$ 4	$ 4

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, 2020	Mar. 31, 2019
FV-NI:
Realized gains	$ 23	$ 35
Realized losses	65	30
AFS:
Realized gains	20	10
Realized losses	6	11
Duke Energy Carolinas
FV-NI:
Realized gains	9	23
Realized losses	45	21
AFS:
Realized gains	12	9
Realized losses	5	10
Progress Energy
FV-NI:
Realized gains	14	12
Realized losses	20	9
AFS:
Realized gains	5	1
Realized losses	1	1
Duke Energy Progress
FV-NI:
Realized gains	14	10
Realized losses	20	8
AFS:
Realized gains	5	1
Realized losses	$ 1	$ 1

Investments in Debt and Equit_5

Investments in Debt and Equity Securities (Maturities) (Details) $ in Millions	Mar. 31, 2020USD ($)
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	$ 333
Due after one through five years	538
Due after five through 10 years	465
Due after 10 years	1,375
Total	2,711
Duke Energy Carolinas
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	25
Due after one through five years	234
Due after five through 10 years	188
Due after 10 years	734
Total	1,181
Progress Energy
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	302
Due after one through five years	236
Due after five through 10 years	214
Due after 10 years	541
Total	1,293
Duke Energy Progress
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	26
Due after one through five years	227
Due after five through 10 years	207
Due after 10 years	506
Total	966
Duke Energy Florida
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	276
Due after one through five years	9
Due after five through 10 years	7
Due after 10 years	35
Total	327
Duke Energy Indiana
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	3
Due after one through five years	17
Due after five through 10 years	7
Due after 10 years	16
Total	$ 43

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value Measurement Amounts for Assets and Liabilities) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	$ 2,711
Derivative assets	34	$ 25
Total assets	7,545	8,610
Derivative liabilities	(390)	(277)
Net assets (liabilities)	7,155	8,310
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	3	3
Total assets	5,431	6,675
Derivative liabilities	(49)	(15)
Net assets (liabilities)	5,382	6,660
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	28	7
Total assets	2,063	1,869
Derivative liabilities	(250)	(145)
Net assets (liabilities)	1,813	1,701
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	3	15
Total assets	3	15
Derivative liabilities	(91)	(117)
Net assets (liabilities)	(88)	(102)
Not Categorized
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	48	51
Net assets (liabilities)	48	51
NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	4,488	5,684
NDTF equity securities | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	4,440	5,633
NDTF equity securities | Not Categorized
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	48	51
NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	4,488	5,661
Debt securities, available-for-sale	2,540	2,469
NDTF | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	767	826
NDTF | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	1,773	1,643
Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	95	122
Debt securities, available-for-sale	368	310
Other Investments | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	95	122
Debt securities, available-for-sale	126	91
Other Investments | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	242	219
NDTF equity security contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	20
Derivative liabilities		(23)
NDTF equity security contracts | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	20
Derivative liabilities		(23)
Duke Energy Carolinas
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	1,181
Derivative assets	2
Total assets	3,714	4,347
Derivative liabilities	(74)	(49)
Net assets (liabilities)	3,640	4,298
Duke Energy Carolinas | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	2,632	3,330
Net assets (liabilities)	2,632	3,330
Duke Energy Carolinas | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	2
Total assets	1,034	966
Derivative liabilities	(74)	(49)
Net assets (liabilities)	960	917
Duke Energy Carolinas | Not Categorized
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	48	51
Net assets (liabilities)	48	51
Duke Energy Carolinas | NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	2,498	3,154
Duke Energy Carolinas | NDTF equity securities | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	2,450	3,103
Duke Energy Carolinas | NDTF equity securities | Not Categorized
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	48	51
Duke Energy Carolinas | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	2,498	3,154
Debt securities, available-for-sale	1,214	1,193
Duke Energy Carolinas | NDTF | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	182	227
Duke Energy Carolinas | NDTF | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	1,032	966
Progress Energy
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	1,293
Derivative assets	25	7
Total assets	3,483	3,913
Derivative liabilities	(95)	(65)
Net assets (liabilities)	3,388	3,825
Progress Energy | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	2,644	3,178
Net assets (liabilities)	2,644	3,178
Progress Energy | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	25	7
Total assets	839	735
Derivative liabilities	(95)	(65)
Net assets (liabilities)	744	647
Progress Energy | NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	1,990	2,530
Progress Energy | NDTF equity securities | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	1,990	2,530
Progress Energy | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	1,990	2,507
Debt securities, available-for-sale	1,326	1,276
Progress Energy | NDTF | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	585	599
Progress Energy | NDTF | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	741	677
Progress Energy | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	122	100
Progress Energy | Other Investments | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	69	49
Progress Energy | Other Investments | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	53	51
Progress Energy | NDTF equity security contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	20
Derivative liabilities		(23)
Progress Energy | NDTF equity security contracts | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	20
Derivative liabilities		(23)
Duke Energy Progress
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	966
Derivative assets	5
Total assets	2,655	3,053
Derivative liabilities	(51)	(49)
Net assets (liabilities)	2,604	3,004
Duke Energy Progress | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	1,909	2,376
Net assets (liabilities)	1,909	2,376
Duke Energy Progress | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	5
Total assets	746	677
Derivative liabilities	(51)	(49)
Net assets (liabilities)	695	628
Duke Energy Progress | NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	1,631	2,077
Duke Energy Progress | NDTF equity securities | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	1,631	2,077
Duke Energy Progress | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	1,631	2,077
Debt securities, available-for-sale	1,017	974
Duke Energy Progress | NDTF | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	276	297
Duke Energy Progress | NDTF | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	741	677
Duke Energy Progress | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	2	2
Duke Energy Progress | Other Investments | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	2	2
Duke Energy Florida
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	327
Derivative assets		7
Total assets	744	817
Derivative liabilities	(29)	(1)
Net assets (liabilities)	715	793
Duke Energy Florida | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	671	759
Net assets (liabilities)	671	759
Duke Energy Florida | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets		7
Total assets	73	58
Derivative liabilities	(29)	(1)
Net assets (liabilities)	44	34
Duke Energy Florida | NDTF equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	359	453
Duke Energy Florida | NDTF equity securities | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	359	453
Duke Energy Florida | NDTF
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	359	430
Debt securities, available-for-sale	309	302
Duke Energy Florida | NDTF | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	309	302
Duke Energy Florida | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	56	55
Duke Energy Florida | Other Investments | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	3	4
Duke Energy Florida | Other Investments | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	53	51
Duke Energy Florida | NDTF equity security contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	20
Derivative liabilities		(23)
Duke Energy Florida | NDTF equity security contracts | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	20
Derivative liabilities		(23)
Duke Energy Indiana
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	63	81
Debt securities, available-for-sale	43
Derivative assets	2	13
Total assets	108	138
Derivative liabilities		(1)
Net assets (liabilities)	108	137
Duke Energy Indiana | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets		2
Total assets	63	83
Derivative liabilities	0	(1)
Net assets (liabilities)	63	82
Duke Energy Indiana | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	43	44
Net assets (liabilities)	43	44
Duke Energy Indiana | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	2	11
Total assets	2	11
Net assets (liabilities)	2	11
Duke Energy Indiana | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	63	81
Duke Energy Indiana | Other Investments | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	63	81
Piedmont Natural Gas
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	3	1
Derivative liabilities	(91)	(117)
Net assets (liabilities)	(88)	(116)
Piedmont Natural Gas | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	3	1
Net assets (liabilities)	3	1
Piedmont Natural Gas | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	(91)	(117)
Net assets (liabilities)	(91)	(117)
Debt Securities | Duke Energy Indiana | Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	43	44
Debt Securities | Duke Energy Indiana | Other Investments | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	$ 43	$ 44

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, 2020	Mar. 31, 2019
Derivatives (net)
Balance at beginning of period	$ (102)	$ (113)
Purchases, sales, issuances and settlements:
Settlements	(9)	(12)
Total gains included on the Condensed Consolidated Balance Sheet	23	10
Balance at end of period	(88)	(115)
Duke Energy Indiana
Derivatives (net)
Balance at beginning of period	11	22
Purchases, sales, issuances and settlements:
Settlements	(6)	(10)
Total gains included on the Condensed Consolidated Balance Sheet	(3)	(7)
Balance at end of period	2	5
Piedmont Natural Gas
Derivatives (net)
Balance at beginning of period	(117)	(141)
Purchases, sales, issuances and settlements:
Total gains and settlements	26	20
Balance at end of period	$ (91)	$ (121)

Fair Value Measurements (Quanti

Fair Value Measurements (Quantitative Level 3 Fair Value Disclosures) (Details) $ in Millions	Mar. 31, 2020USD ($)$ / MWh$ / MMBTU	Dec. 31, 2019USD ($)$ / MWh$ / MMBTU	Mar. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Fair Value Measurement Inputs and Valuation Techniques
Net derivative asset (liability) | $	$ (88)	$ (102)	$ (115)	$ (113)
Duke Energy Ohio | FTRs | RTO auction pricing
Fair Value Measurement Inputs and Valuation Techniques
Net derivative asset (liability) | $	$ 1	$ 4
Duke Energy Ohio | FTRs | Minimum | RTO auction pricing
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu) | $ / MWh	0.04	0.59
Duke Energy Ohio | FTRs | Maximum | RTO auction pricing
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu) | $ / MWh	3.29	3.47
Duke Energy Ohio | FTRs | Weighted Average | RTO auction pricing
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu) | $ / MWh	1.03	2.07
Duke Energy Indiana
Fair Value Measurement Inputs and Valuation Techniques
Net derivative asset (liability) | $	$ 2	$ 11	5	22
Duke Energy Indiana | FTRs | RTO auction pricing
Fair Value Measurement Inputs and Valuation Techniques
Net derivative asset (liability) | $	$ 2	$ 11
Duke Energy Indiana | FTRs | Minimum | RTO auction pricing
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu) | $ / MWh	(0.37)	(0.66)
Duke Energy Indiana | FTRs | Maximum | RTO auction pricing
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu) | $ / MWh	6.06	9.24
Duke Energy Indiana | FTRs | Weighted Average | RTO auction pricing
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu) | $ / MWh	0.54	1.15
Piedmont Natural Gas
Fair Value Measurement Inputs and Valuation Techniques
Net derivative asset (liability) | $	$ (91)	$ (117)	$ (121)	$ (141)
Piedmont Natural Gas | Natural gas contracts | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques
Net derivative asset (liability) | $	$ (91)	$ (117)
Piedmont Natural Gas | Natural gas contracts | Minimum | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu) | $ / MMBTU	1.64	1.59
Piedmont Natural Gas | Natural gas contracts | Maximum | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu) | $ / MMBTU	2.41	2.46
Piedmont Natural Gas | Natural gas contracts | Weighted Average | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu) | $ / MMBTU	1.94	1.91

Fair Value Measurements (Other

Fair Value Measurements (Other Fair Value Disclosure) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	$ 61,388	$ 58,126
Long-term debt, fair value	65,644	63,062
Piedmont Natural Gas and Progress Energy [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unamortized debt discount (premium), net	1,400	1,500
Duke Energy Carolinas
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	12,807	11,900
Long-term debt, fair value	14,312	13,516
Progress Energy
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	19,355	19,634
Long-term debt, fair value	21,802	22,291
Duke Energy Progress
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	9,059	9,058
Long-term debt, fair value	9,798	9,934
Duke Energy Florida
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	7,706	7,987
Long-term debt, fair value	8,831	9,131
Duke Energy Ohio
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	2,620	2,619
Long-term debt, fair value	2,904	2,964
Duke Energy Indiana
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	4,603	4,057
Long-term debt, fair value	5,433	4,800
Piedmont Natural Gas
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	2,385	2,384
Long-term debt, fair value	$ 2,551	$ 2,642

Variable Interest Entities (Nar

Variable Interest Entities (Narrative) (Details) - USD ($)	Mar. 31, 2018	Mar. 31, 2020	Dec. 31, 2019
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates		$ 2,067,000,000	$ 1,936,000,000
VIE primary beneficiary
Variable Interest Entities [Line Items]
Variable interest entity, financial or other support, amount		0	0
VIE not primary beneficiary
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates		1,614,000,000	1,479,000,000
FES
Variable Interest Entities [Line Items]
Power participation ratio	4.85%
ACP | VIE not primary beneficiary
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates		1,243,000,000	$ 1,179,000,000
ACP | Financial guarantee
Variable Interest Entities [Line Items]
Maximum potential amount of future payments associated with guarantees		$ 845,000,000
Percentage of potential amount of future payments associated with guarantees as percent of outstanding borrowings		47.00%
CRC | VIE primary beneficiary
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
OVEC | VIE not primary beneficiary
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 ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Variable Interest Entities [Line Items]
Long-Term Debt	$ 56,311	$ 54,985
Duke Energy Carolinas
Variable Interest Entities [Line Items]
Long-Term Debt	12,050	11,142
Duke Energy Progress
Variable Interest Entities [Line Items]
Long-Term Debt	7,903	7,902
Duke Energy Florida
Variable Interest Entities [Line Items]
Long-Term Debt	7,384	7,416
CRC | VIE primary beneficiary
Variable Interest Entities [Line Items]
Facility size	350
Long-Term Debt	350	350
Accounts receivable from securitization	467	522
DERF | Duke Energy Carolinas | VIE primary beneficiary
Variable Interest Entities [Line Items]
Facility size	475
Long-Term Debt	475	474
Accounts receivable from securitization	616	642
DEPR | Duke Energy Progress | VIE primary beneficiary
Variable Interest Entities [Line Items]
Facility size	375
Long-Term Debt	325	325
Accounts receivable from securitization	410	489
DEFR | Duke Energy Florida | VIE primary beneficiary
Variable Interest Entities [Line Items]
Facility size	250
Long-Term Debt	250	250
Accounts receivable from securitization	$ 331	$ 336

Variable Interest Entities (S_2

Variable Interest Entities (Schedule of Consolidated VIEs) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory Assets: Current	$ 1,770	$ 1,796
Current Assets: Other	1,000	764
Other Noncurrent Assets: Regulatory assets	13,413	13,222
Property, Plant and Equipment: Cost	149,676	147,654
Accumulated depreciation and amortization	(46,599)	(45,773)
Other Noncurrent Assets: Other	3,315	3,289
Current Liabilities: Other	2,004	2,367
Current maturities of long-term debt	5,077	3,141
Long-Term Debt	56,311	54,985
Other Noncurrent Liabilities: AROs	12,497	12,437
Other Noncurrent Liabilities: Other	1,669	1,581
Duke Energy Carolinas
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory Assets: Current	524	550
Current Assets: Other	31	21
Other Noncurrent Assets: Regulatory assets	3,427	3,360
Property, Plant and Equipment: Cost	49,534	48,922
Accumulated depreciation and amortization	(16,884)	(16,525)
Other Noncurrent Assets: Other	1,136	1,149
Current Liabilities: Other	479	611
Current maturities of long-term debt	457	458
Long-Term Debt	12,050	11,142
Other Noncurrent Liabilities: AROs	5,552	5,528
Other Noncurrent Liabilities: Other	640	627
Duke Energy Progress
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory Assets: Current	503	526
Current Assets: Other	48	60
Other Noncurrent Assets: Regulatory assets	4,392	4,152
Property, Plant and Equipment: Cost	34,898	34,603
Accumulated depreciation and amortization	(12,114)	(11,915)
Other Noncurrent Assets: Other	682	651
Current Liabilities: Other	429	478
Current maturities of long-term debt	1,006	1,006
Long-Term Debt	7,903	7,902
Other Noncurrent Liabilities: AROs	5,442	5,408
Other Noncurrent Liabilities: Other	83	92
Duke Energy Florida
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory Assets: Current	451	419
Current Assets: Other	37	58
Other Noncurrent Assets: Regulatory assets	2,097	2,194
Property, Plant and Equipment: Cost	20,880	20,457
Accumulated depreciation and amortization	(5,339)	(5,236)
Other Noncurrent Assets: Other	329	311
Current Liabilities: Other	383	415
Current maturities of long-term debt	322	571
Long-Term Debt	7,384	7,416
Other Noncurrent Liabilities: AROs	578	578
Other Noncurrent Liabilities: Other	169	136
DEFPF | Duke Energy Florida | VIE primary beneficiary
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	4	5
Regulatory Assets: Current	53	52
Current Assets: Other	13	39
Other Noncurrent Assets: Regulatory assets	980	989
Current Liabilities: Other	2	10
Current maturities of long-term debt	54	54
Long-Term Debt	1,028	1,057
DERF | Duke Energy Carolinas | VIE primary beneficiary
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	616	642
Long-Term Debt	475	474
DEPR | Duke Energy Progress | VIE primary beneficiary
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	410	489
Long-Term Debt	325	325
DEFR | Duke Energy Florida | VIE primary beneficiary
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	331	336
Long-Term Debt	250	250
CRC | VIE primary beneficiary
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	467	522
Long-Term Debt	350	350
Commercial Renewables | VIE primary beneficiary
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Current Assets: Other	287	203
Property, Plant and Equipment: Cost	6,106	5,747
Accumulated depreciation and amortization	(1,094)	(1,041)
Other Noncurrent Assets: Other	82	106
Current maturities of long-term debt	162	162
Long-Term Debt	1,538	1,541
Other Noncurrent Liabilities: AROs	129	127
Other Noncurrent Liabilities: Other	$ 258	$ 228

Variable Interest Entities (S_3

Variable Interest Entities (Schedule of Non-Consolidated VIEs) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates	$ 2,067	$ 1,936
Taxes accrued	493	392
Current Liabilities: Other	2,004	2,367
Deferred income taxes	9,321	8,878
Other Noncurrent Liabilities: Other	1,669	1,581
VIE not primary beneficiary
Variable Interest Entities [Line Items]
Receivables from affiliated companies	(1)	(1)
Investments in equity method unconsolidated affiliates	1,614	1,479
Total assets	1,613	1,478
Taxes accrued	(1)	(1)
Current Liabilities: Other	3	4
Deferred income taxes	69	59
Other Noncurrent Liabilities: Other	116	11
Total liabilities	187	73
Net assets	1,426	1,405
Pipeline Investments | VIE not primary beneficiary
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates	1,243	1,179
Total assets	1,243	1,179
Taxes accrued	(1)	(1)
Deferred income taxes	69	59
Other Noncurrent Liabilities: Other	105
Total liabilities	173	58
Net assets	1,070	1,121
Commercial Renewables | VIE not primary beneficiary
Variable Interest Entities [Line Items]
Receivables from affiliated companies	(1)	(1)
Investments in equity method unconsolidated affiliates	371	300
Total assets	370	299
Net assets	370	299
Other VIEs | VIE not primary beneficiary
Variable Interest Entities [Line Items]
Current Liabilities: Other	3	4
Other Noncurrent Liabilities: Other	11	11
Total liabilities	14	15
Net assets	(14)	(15)
Duke Energy Ohio
Variable Interest Entities [Line Items]
Receivables from affiliated companies	52	92
Taxes accrued	170	219
Current Liabilities: Other	68	75
Deferred income taxes	942	922
Other Noncurrent Liabilities: Other	97	94
Duke Energy Ohio | VIE not primary beneficiary
Variable Interest Entities [Line Items]
Receivables from affiliated companies	39	64
Total assets	39	64
Net assets	39	64
Duke Energy Indiana
Variable Interest Entities [Line Items]
Receivables from affiliated companies	76	79
Taxes accrued	81	49
Current Liabilities: Other	92	112
Deferred income taxes	1,158	1,150
Other Noncurrent Liabilities: Other	30	18
Duke Energy Indiana | VIE not primary beneficiary
Variable Interest Entities [Line Items]
Receivables from affiliated companies	48	77
Total assets	48	77
Net assets	$ 48	$ 77

Variable Interest Entities (Pip

Variable Interest Entities (Pipeline Investments) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Variable Interest Entities [Line Items]
Investments in joint ventures	$ 2,067	$ 1,936
VIE not primary beneficiary
Variable Interest Entities [Line Items]
Investments in joint ventures	$ 1,614	1,479
ACP
Variable Interest Entities [Line Items]
Ownership percentage	47.00%
ACP | VIE not primary beneficiary
Variable Interest Entities [Line Items]
Investments in joint ventures	$ 1,243	1,179
Constitution
Variable Interest Entities [Line Items]
Ownership percentage	24.00%
Pipeline Investments | VIE not primary beneficiary
Variable Interest Entities [Line Items]
Investments in joint ventures	$ 1,243	$ 1,179

Variable Interest Entities (Rec

Variable Interest Entities (Receivables Sold) (Details) - VIE not primary beneficiary - CRC - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Duke Energy Ohio
Variable Interest Entities [Line Items]
Receivables sold	$ 234	$ 253
Less: Retained interests	39	64
Net receivables sold	195	189
Duke Energy Indiana
Variable Interest Entities [Line Items]
Receivables sold	274	307
Less: Retained interests	48	77
Net receivables sold	$ 226	$ 230

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, 2020	Mar. 31, 2019
Duke Energy Ohio
Variable Interest Entities [Line Items]
Receivables sold	$ 537	$ 575
Loss recognized on sale	4	4
Cash proceeds from receivables sold	559	597
Return received on retained interests	2	2
Duke Energy Indiana
Variable Interest Entities [Line Items]
Receivables sold	647	734
Loss recognized on sale	4	5
Cash proceeds from receivables sold	672	758
Return received on retained interests	$ 2	$ 3

Revenue (Remaining Performance

Revenue (Remaining Performance Obligations) (Details) $ in Millions	Mar. 31, 2020USD ($)
Progress Energy
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 410
Progress Energy | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01
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	$ 84
Progress Energy | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
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	$ 92
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	$ 87
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
Revenue, remaining performance obligation, amount	$ 58
Duke Energy Progress
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 38
Duke Energy Progress | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01
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]: 2021-01-01
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]: 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
Duke Energy Florida
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 372
Duke Energy Florida | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01
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	$ 78
Duke Energy Florida | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
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	$ 84
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	$ 79
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
Revenue, remaining performance obligation, amount	$ 58
Duke Energy Indiana
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 13
Duke Energy Indiana | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01
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	$ 8
Duke Energy Indiana | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
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	$ 5
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
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
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
Piedmont Natural Gas
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 675
Piedmont Natural Gas | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01
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	$ 51
Piedmont Natural Gas | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
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	$ 65
Piedmont Natural Gas | 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	$ 64
Piedmont Natural Gas | 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	$ 61
Piedmont Natural Gas | 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	$ 58
Piedmont Natural Gas | 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
Revenue, remaining performance obligation, amount	$ 376

Revenue (Remaining Performanc_2

Revenue (Remaining Performance Obligations Total) (Details) (Details) $ in Millions	Mar. 31, 2020USD ($)
Progress Energy
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 410
Duke Energy Progress
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	38
Duke Energy Florida [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	372
Duke Energy Indiana
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	13
Piedmont Natural Gas
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 675

Revenue (Disaggregation of Reve

Revenue (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 5,800	$ 5,998
Revenue from sources other than contracts with customers	149	165
Total operating revenues	5,949	6,163
Electric Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	5,134	5,221
Total operating revenues	5,174	5,321
Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,261	2,370
Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | General
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,492	1,427
Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	693	711
Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	497	541
Electric Utilities and Infrastructure | Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	191	172
Gas Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	602	731
Total operating revenues	640	732
Gas Utilities and Infrastructure | Gas Utilities and Infrastructure | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	362	414
Gas Utilities and Infrastructure | Gas Utilities and Infrastructure | Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	169	206
Gas Utilities and Infrastructure | Gas Utilities and Infrastructure | Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	41	48
Gas Utilities and Infrastructure | Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	30	63
Commercial Renewables
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	58	42
Total operating revenues	129	106
Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6	4
Total operating revenues	6	4
Duke Energy Carolinas
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,748	1,719
Revenue from sources other than contracts with customers		25
Total operating revenues	1,748	1,744
Duke Energy Carolinas | Electric Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,748	1,719
Duke Energy Carolinas | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	756	760
Duke Energy Carolinas | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | General
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	549	496
Duke Energy Carolinas | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	269	266
Duke Energy Carolinas | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	114	119
Duke Energy Carolinas | Electric Utilities and Infrastructure | Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	60	78
Progress Energy
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,367	2,493
Revenue from sources other than contracts with customers	55	79
Total operating revenues	2,422	2,572
Progress Energy | Electric Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,367	2,493
Progress Energy | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,064	1,114
Progress Energy | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | General
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	648	632
Progress Energy | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	216	222
Progress Energy | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	321	353
Progress Energy | Electric Utilities and Infrastructure | Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	118	172
Duke Energy Progress
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,317	1,443
Revenue from sources other than contracts with customers	21	41
Total operating revenues	1,338	1,484
Duke Energy Progress | Electric Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,317	1,443
Duke Energy Progress | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	502	536
Duke Energy Progress | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | General
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	319	306
Duke Energy Progress | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	154	161
Duke Energy Progress | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	279	315
Duke Energy Progress | Electric Utilities and Infrastructure | Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	63	125
Duke Energy Florida
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,050	1,050
Revenue from sources other than contracts with customers	30	36
Total operating revenues	1,080	1,086
Duke Energy Florida | Electric Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,050	1,050
Duke Energy Florida | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	562	578
Duke Energy Florida | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | General
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	329	326
Duke Energy Florida | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	62	61
Duke Energy Florida | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	42	38
Duke Energy Florida | Electric Utilities and Infrastructure | Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	55	47
Duke Energy Ohio
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	504	531
Revenue from sources other than contracts with customers	(6)
Total operating revenues	498	531
Duke Energy Ohio | Electric Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	352	355
Duke Energy Ohio | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	176	189
Duke Energy Ohio | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | General
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	114	103
Duke Energy Ohio | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	35	33
Duke Energy Ohio | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	7	14
Duke Energy Ohio | Electric Utilities and Infrastructure | Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	20	16
Duke Energy Ohio | Gas Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	152	176
Duke Energy Ohio | Gas Utilities and Infrastructure | Gas Utilities and Infrastructure | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	97	112
Duke Energy Ohio | Gas Utilities and Infrastructure | Gas Utilities and Infrastructure | Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	43	49
Duke Energy Ohio | Gas Utilities and Infrastructure | Gas Utilities and Infrastructure | Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6	7
Duke Energy Ohio | Gas Utilities and Infrastructure | Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6	8
Duke Energy Indiana
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	692	764
Revenue from sources other than contracts with customers		4
Total operating revenues	692	768
Duke Energy Indiana | Electric Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	692	764
Duke Energy Indiana | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	265	306
Duke Energy Indiana | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | General
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	181	197
Duke Energy Indiana | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	175	190
Duke Energy Indiana | Electric Utilities and Infrastructure | Electric Utilities and Infrastructure | Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	55	54
Duke Energy Indiana | Electric Utilities and Infrastructure | Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	16	17
Duke Energy Indiana | Gas Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers		0
Piedmont Natural Gas
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	461	570
Revenue from sources other than contracts with customers	51	9
Total operating revenues	512	579
Piedmont Natural Gas | Gas Utilities and Infrastructure
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	461	570
Piedmont Natural Gas | Gas Utilities and Infrastructure | Gas Utilities and Infrastructure | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	264	302
Piedmont Natural Gas | Gas Utilities and Infrastructure | Gas Utilities and Infrastructure | Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	126	157
Piedmont Natural Gas | Gas Utilities and Infrastructure | Gas Utilities and Infrastructure | Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	36	42
Piedmont Natural Gas | Gas Utilities and Infrastructure | Gas Utilities and Infrastructure | Power Generation
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	11	13
Piedmont Natural Gas | Gas Utilities and Infrastructure | Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 24	$ 56

Revenue (Reserve for Credit Los

Revenue (Reserve for Credit Losses for Trade and Other Receivables) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020USD ($)
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at December 31, 2019	$ 76
Cumulative Change in Accounting Principle	89
Write-Offs	(10)
Credit Loss Expense	18
Balance at March 31, 2020	89
Duke Energy Carolinas
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at December 31, 2019	10
Cumulative Change in Accounting Principle	11
Write-Offs	(3)
Credit Loss Expense	3
Balance at March 31, 2020	11
Progress Energy
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at December 31, 2019	16
Cumulative Change in Accounting Principle	20
Write-Offs	(4)
Credit Loss Expense	6
Balance at March 31, 2020	20
Duke Energy Progress
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at December 31, 2019	8
Cumulative Change in Accounting Principle	9
Write-Offs	(2)
Credit Loss Expense	2
Balance at March 31, 2020	9
Duke Energy Florida
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at December 31, 2019	7
Cumulative Change in Accounting Principle	11
Write-Offs	(2)
Credit Loss Expense	5
Balance at March 31, 2020	11
Duke Energy Ohio
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at December 31, 2019	4
Cumulative Change in Accounting Principle	5
Credit Loss Expense	1
Balance at March 31, 2020	5
Duke Energy Indiana
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at December 31, 2019	3
Cumulative Change in Accounting Principle	3
Balance at March 31, 2020	3
Piedmont Natural Gas
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at December 31, 2019	6
Cumulative Change in Accounting Principle	9
Write-Offs	(1)
Credit Loss Expense	3
Balance at March 31, 2020	9
Cumulative Change in Accounting Principle
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at December 31, 2019	5
Cumulative Change in Accounting Principle	5
Cumulative Change in Accounting Principle | Duke Energy Carolinas
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at December 31, 2019	1
Cumulative Change in Accounting Principle	1
Cumulative Change in Accounting Principle | Progress Energy
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at December 31, 2019	2
Cumulative Change in Accounting Principle	2
Cumulative Change in Accounting Principle | Duke Energy Progress
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at December 31, 2019	1
Cumulative Change in Accounting Principle	1
Cumulative Change in Accounting Principle | Duke Energy Florida
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at December 31, 2019	1
Cumulative Change in Accounting Principle	1
Cumulative Change in Accounting Principle | Piedmont Natural Gas
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at December 31, 2019	1
Cumulative Change in Accounting Principle	$ 1

Revenue (Aging of Trade Receiva

Revenue (Aging of Trade Receivables) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Unbilled Receivables	$ 716	$ 843
Trade and Other Receivables, not past due	1,584
Trade and Other Receivables	2,726
30-60 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	216
60-90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	65
90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	145
Duke Energy Carolinas
Financing Receivable, Past Due [Line Items]
Unbilled Receivables	285	298
Trade and Other Receivables, not past due	448
Trade and Other Receivables	839
Duke Energy Carolinas | 30-60 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	69
Duke Energy Carolinas | 60-90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	18
Duke Energy Carolinas | 90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	19
Progress Energy
Financing Receivable, Past Due [Line Items]
Unbilled Receivables	195	217
Trade and Other Receivables, not past due	585
Trade and Other Receivables	924
Progress Energy | 30-60 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	67
Progress Energy | 60-90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	20
Progress Energy | 90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	57
Duke Energy Progress
Financing Receivable, Past Due [Line Items]
Unbilled Receivables	85	122
Trade and Other Receivables, not past due	321
Trade and Other Receivables	496
Duke Energy Progress | 30-60 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	44
Duke Energy Progress | 60-90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	14
Duke Energy Progress | 90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	32
Duke Energy Florida
Financing Receivable, Past Due [Line Items]
Unbilled Receivables	110	95
Trade and Other Receivables, not past due	262
Trade and Other Receivables	426
Duke Energy Florida | 30-60 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	23
Duke Energy Florida | 60-90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	6
Duke Energy Florida | 90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	25
Duke Energy Ohio
Financing Receivable, Past Due [Line Items]
Unbilled Receivables	1	1
Trade and Other Receivables, not past due	45
Trade and Other Receivables	89
Duke Energy Ohio | 30-60 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	9
Duke Energy Ohio | 60-90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	2
Duke Energy Ohio | 90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	32
Duke Energy Indiana
Financing Receivable, Past Due [Line Items]
Unbilled Receivables	16	16
Trade and Other Receivables, not past due	24
Trade and Other Receivables	53
Duke Energy Indiana | 30-60 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	1
Duke Energy Indiana | 60-90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	1
Duke Energy Indiana | 90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	11
Piedmont Natural Gas
Financing Receivable, Past Due [Line Items]
Unbilled Receivables	32	$ 78
Trade and Other Receivables, not past due	134
Trade and Other Receivables	200
Piedmont Natural Gas | 30-60 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	18
Piedmont Natural Gas | 60-90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	5
Piedmont Natural Gas | 90 days
Financing Receivable, Past Due [Line Items]
Trade and Other Receivables	$ 11

Revenue (Unbilled Revenues) (De

Revenue (Unbilled Revenues) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled Receivables	$ 716	$ 843
Duke Energy Carolinas
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled Receivables	285	298
Progress Energy
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled Receivables	195	217
Duke Energy Progress
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled Receivables	85	122
Duke Energy Florida
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled Receivables	110	95
Duke Energy Ohio
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled Receivables	1	1
Duke Energy Indiana
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled Receivables	16	16
Piedmont Natural Gas
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled Receivables	32	78
CRC | Duke Energy Ohio
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled Receivables	61	82
CRC | Duke Energy Indiana
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled Receivables	$ 94	$ 115

Stockholders' Equity (Earnings

Stockholders' Equity (Earnings Per Share Data) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Class of Stock [Line Items]
Income from continuing operations available to Duke Energy common stockholders excluding impact of participating securities and including accumulated preferred stock dividends adjustment	$ 911	$ 898
Weighted average common shares outstanding – basic (in shares)	734	727
Equity Forwards (in shares)	2
Weighted average common shares outstanding – diluted (in shares)	736	727
Basic and diluted (in usd per share)	$ 1.24	$ 1.24
Potentially dilutive items excluded from the calculation (in shares)	2	2
Common Stock
Class of Stock [Line Items]
Dividends declared per common share (in usd per share)	$ 0.945	$ 0.9275
Preferred stock, Series A
Class of Stock [Line Items]
Dividends declared on preferred stock per depositary share (in usd per share)	$ 0.359
Cumulative dividend rate per annum	5.75%
Price per share (in usd per share)	$ 25
Preferred stock, Series B
Class of Stock [Line Items]
Dividends declared on preferred stock per depositary share (in usd per share)	$ 24.917
Cumulative dividend rate per annum	4.875%
Liquidation preference per share (in usd per share)	$ 1,000

Stockholders' Equity (Common St

Stockholders' Equity (Common Stock) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Billions	1 Months Ended
	Mar. 31, 2020	Nov. 30, 2019
Forward Contract Indexed to Issuer's Equity [Line Items]
Maximum value of shares to be issued under ATM program		$ 1.5
Equity forwards
Forward Contract Indexed to Issuer's Equity [Line Items]
Shares offered	940	28,750
Forward contract indexed to issuer's equity, forward rate per share	$ 89.76	$ 85.99

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, 2020	Mar. 31, 2019
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 41	$ 37
Interest cost on projected benefit obligation	67	83
Expected return on plan assets	(143)	(143)
Amortization of actuarial loss	34	24
Amortization of prior service credit	(8)	(8)
Amortization of settlement charges	2
Net periodic pension costs	(7)	(7)
Duke Energy Carolinas
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	12	12
Interest cost on projected benefit obligation	16	20
Expected return on plan assets	(36)	(38)
Amortization of actuarial loss	7	6
Amortization of prior service credit	(2)	(2)
Amortization of settlement charges	1
Net periodic pension costs	(2)	(2)
Progress Energy
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	12	11
Interest cost on projected benefit obligation	21	26
Expected return on plan assets	(48)	(44)
Amortization of actuarial loss	11	9
Amortization of prior service credit	(1)	(1)
Amortization of settlement charges	1
Net periodic pension costs	(4)	1
Duke Energy Progress
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	6	6
Interest cost on projected benefit obligation	10	12
Expected return on plan assets	(22)	(23)
Amortization of actuarial loss	5	3
Net periodic pension costs	(1)	(2)
Duke Energy Florida
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	5	4
Interest cost on projected benefit obligation	12	14
Expected return on plan assets	(25)	(22)
Amortization of actuarial loss	6	6
Net periodic pension costs	(2)	2
Duke Energy Ohio
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	1	1
Interest cost on projected benefit obligation	4	5
Expected return on plan assets	(7)	(8)
Amortization of actuarial loss	2	1
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	6	6
Expected return on plan assets	(11)	(11)
Amortization of actuarial loss	3	2
Net periodic pension costs		(1)
Piedmont Natural Gas
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	1	1
Interest cost on projected benefit obligation	2	3
Expected return on plan assets	(5)	(5)
Amortization of actuarial loss	2	2
Amortization of prior service credit	(2)	(3)
Net periodic pension costs	$ (2)	$ (2)

Income Taxes (Effective Tax Rat

Income Taxes (Effective Tax Rates) (Details)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
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%	9.60%
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	16.10%	17.70%
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	17.50%	17.30%
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	17.10%	17.80%
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	20.00%	19.30%
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	17.70%	16.90%
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	20.80%	24.10%
Piedmont Natural Gas
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	10.10%	21.80%

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020USD ($)
AMT credit carryforwards
Tax Credit Carryforward [Line Items]
Tax refund	$ 572