Duke Energy (DUK) 10-Q 6 Aug 19 2019 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 30, 2019	Jul. 31, 2019
Document Information [Line Items]
Entity Shell Company	false
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Document Transition Report	false
Document Quarterly Report	true
Entity Registrant Name	DUKE ENERGY CORP
Entity Central Index Key	0001326160
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2019
Entity File Number	1-32853
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		728,601,060
Entity Emerging Growth Company	false
Entity Small Business	false
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
Duke Energy Carolinas [Member]
Document Information [Line Items]
Entity Shell Company	false
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Entity Registrant Name	DUKE ENERGY CAROLINAS, LLC
Entity Central Index Key	0000030371
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity File Number	1-4928
Entity Emerging Growth Company	false
Entity Small Business	false
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
Progress Energy [Member]
Document Information [Line Items]
Entity Shell Company	false
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Entity Registrant Name	PROGRESS ENERGY, INC.
Entity Central Index Key	0001094093
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity File Number	1-15929
Entity Emerging Growth Company	false
Entity Small Business	false
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
Duke Energy Progress [Member]
Document Information [Line Items]
Entity Shell Company	false
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Entity Registrant Name	DUKE ENERGY PROGRESS, LLC
Entity Central Index Key	0000017797
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity File Number	1-3382
Entity Emerging Growth Company	false
Entity Small Business	false
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
Duke Energy Florida [Member]
Document Information [Line Items]
Entity Shell Company	false
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Entity Registrant Name	DUKE ENERGY FLORIDA, LLC
Entity Central Index Key	0000037637
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity File Number	1-3274
Entity Small Business	false
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
Duke Energy Ohio [Member]
Document Information [Line Items]
Entity Shell Company	false
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Entity Registrant Name	DUKE ENERGY OHIO, INC.
Entity Central Index Key	0000020290
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity File Number	1-1232
Entity Small Business	false
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
Duke Energy Indiana [Member]
Document Information [Line Items]
Entity Shell Company	false
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Entity Registrant Name	DUKE ENERGY INDIANA, LLC
Entity Central Index Key	0000081020
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity File Number	1-3543
Entity Small Business	false
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
Piedmont Natural Gas [Member]
Document Information [Line Items]
Entity Shell Company	false
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Entity Registrant Name	PIEDMONT NATURAL GAS COMPANY, INC.
Entity Central Index Key	0000078460
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity File Number	1-6196
Entity Small Business	false
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
Common Stock [Member]
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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Operating Revenues
Regulated electric	$ 5,423	$ 5,178	$ 10,708	$ 10,462
Regulated natural gas	280	291	1,008	991
Nonregulated electric and other	170	174	320	325
Total operating revenues	5,873	5,643	12,036	11,778
Operating Expenses
Operation, maintenance and other	1,434	1,544	2,853	3,008
Depreciation and amortization	1,089	973	2,178	1,940
Property and other taxes	334	315	677	631
Impairment charges	4	172	4	215
Total operating expenses	4,578	4,667	9,365	9,446
Gains (Losses) on Sales of Other Assets and Other, net	3	3		(97)
Operating Income	1,298	979	2,671	2,235
Other Income and Expenses
Equity in earnings of unconsolidated affiliates	44	36	87	12
Other income and expenses, net	89	110	204	196
Total other income and expenses	133	146	291	208
Interest Expense	542	518	1,085	1,033
Income From Continuing Operations Before Income Taxes	889	607	1,877	1,410
Income Tax Expense From Continuing Operations	141	100	236	281
Income From Continuing Operations	748	507	1,641	1,129
Loss From Discontinued Operations, net of tax		(5)	0	(5)
Net Income	748	502	1,641	1,124
Less: Net (Loss) Income Attributable to Noncontrolling Interests	(84)	2	(91)	4
Less: Preferred Dividends	12		12
Net Income Attributable to Duke Energy Corporation	820	500	1,720	1,120
Other Comprehensive Income (Loss), net of tax
Pension and OPEB adjustments	3	1	3	2
Reclassification into earnings from cash flow hedges	2	(2)	3	(1)
Unrealized gains (losses) on available-for-sale securities	4	(2)	8	(5)
Other Comprehensive (Loss) Income, net of tax	(20)	(2)	(32)	9
Comprehensive Income	728	500	1,609	1,133
Less: Comprehensive (Loss) Income Attributable to Noncontrolling Interests	(84)	2	(91)	4
Comprehensive Income Attributable to Duke Energy Corporation	$ 800	$ 498	$ 1,688	$ 1,129
Net income attributable to Duke Energy Corporation common stockholders
Continuing Operations, Basic and Diluted (in usd per share)	$ 1.12	$ 0.72	$ 2.36	$ 1.60
Discontinued Operations, Basic and Diluted (in usd per share)		(0.01)		(0.01)
Basic and Diluted (in usd per share)	$ 1.12	$ 0.71	$ 2.36	$ 1.59
Weighted average shares outstanding
Weighted Average Number of Shares Outstanding, Basic	728	703	728	702
Weighted Average Number of Shares Outstanding, Diluted	728	704	728	702
Duke Energy Carolinas [Member]
Operating Revenues
Total operating revenues	$ 1,713	$ 1,672	$ 3,457	$ 3,435
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	395	407	867	880
Operation, maintenance and other	441	499	881	950
Depreciation and amortization	346	289	663	561
Property and other taxes	75	75	155	147
Impairment charges	5	177	5	190
Total operating expenses	1,262	1,447	2,571	2,728
Gains (Losses) on Sales of Other Assets and Other, net		(1)		(1)
Operating Income	451	224	886	706
Other Income and Expenses
Total other income and expenses	41	35	72	74
Interest Expense	117	110	227	217
Income From Continuing Operations Before Income Taxes	375	149	731	563
Income Tax Expense From Continuing Operations	74	32	137	123
Net Income Attributable to Duke Energy Corporation	301	117	594	440
Other Comprehensive Income (Loss), net of tax
Reclassification into earnings from cash flow hedges				1
Other Comprehensive (Loss) Income, net of tax				1
Comprehensive Income Attributable to Duke Energy Corporation	301	117	594	441
Progress Energy [Member]
Operating Revenues
Total operating revenues	2,744	2,498	5,316	5,074
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	988	895	1,913	1,871
Operation, maintenance and other	606	610	1,173	1,233
Depreciation and amortization	426	380	881	764
Property and other taxes	143	131	280	254
Impairment charges		4		33
Total operating expenses	2,163	2,020	4,247	4,155
Gains (Losses) on Sales of Other Assets and Other, net	(1)	6	(1)	12
Operating Income	580	484	1,068	931
Other Income and Expenses
Total other income and expenses	34	42	65	77
Interest Expense	219	203	438	412
Income From Continuing Operations Before Income Taxes	395	323	695	596
Income Tax Expense From Continuing Operations	66	56	118	92
Net Income	329	267	577	504
Less: Net (Loss) Income Attributable to Noncontrolling Interests	1	2	0	4
Net Income Attributable to Duke Energy Corporation	328	265	577	500
Other Comprehensive Income (Loss), net of tax
Pension and OPEB adjustments	1	2	2	2
Reclassification into earnings from cash flow hedges	(1)	(1)	(3)	(3)
Unrealized gains (losses) on available-for-sale securities	1	(1)	1	(1)
Other Comprehensive (Loss) Income, net of tax	3	2	6	4
Comprehensive Income	332	269	583	508
Less: Comprehensive (Loss) Income Attributable to Noncontrolling Interests	1	2		4
Comprehensive Income Attributable to Duke Energy Corporation	331	267	583	504
Duke Energy Progress [Member]
Operating Revenues
Total operating revenues	1,387	1,291	2,871	2,751
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	479	408	994	917
Operation, maintenance and other	357	375	692	756
Depreciation and amortization	251	235	541	470
Property and other taxes	41	40	85	75
Impairment charges		1		33
Total operating expenses	1,128	1,059	2,312	2,251
Gains (Losses) on Sales of Other Assets and Other, net		1		2
Operating Income	259	233	559	502
Other Income and Expenses
Total other income and expenses	24	19	48	37
Interest Expense	81	78	158	159
Income From Continuing Operations Before Income Taxes	202	174	449	380
Income Tax Expense From Continuing Operations	33	35	77	64
Net Income Attributable to Duke Energy Corporation	169	139	372	316
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Attributable to Duke Energy Corporation			372	316
Duke Energy Florida [Member]
Operating Revenues
Total operating revenues	1,353	1,203	2,439	2,318
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	509	486	919	953
Operation, maintenance and other	244	237	474	474
Depreciation and amortization	175	144	340	294
Property and other taxes	103	91	196	179
Total operating expenses	1,031	958	1,929	1,900
Gains (Losses) on Sales of Other Assets and Other, net	(1)		(1)
Operating Income	321	245	509	418
Other Income and Expenses
Total other income and expenses	12	26	25	47
Interest Expense	83	66	165	137
Income From Continuing Operations Before Income Taxes	250	205	369	328
Income Tax Expense From Continuing Operations	49	37	72	57
Net Income Attributable to Duke Energy Corporation	201	168	297	271
Other Comprehensive Income (Loss), net of tax
Unrealized gains (losses) on available-for-sale securities		(1)	1	(1)
Other Comprehensive (Loss) Income, net of tax		(1)	1	(1)
Comprehensive Income Attributable to Duke Energy Corporation	201	167	298	270
Duke Energy Ohio [Member]
Operating Revenues
Regulated electric	336	346	691	682
Regulated natural gas	97	103	273	277
Nonregulated electric and other		10		24
Total operating revenues	433	459	964	983
Operating Expenses
Operation, maintenance and other	123	130	255	261
Depreciation and amortization	66	62	130	132
Property and other taxes	74	68	158	145
Total operating expenses	359	382	786	821
Gains (Losses) on Sales of Other Assets and Other, net				(106)
Operating Income	74	77	178	56
Other Income and Expenses
Total other income and expenses	6	8	15	14
Interest Expense	24	23	54	45
Income From Continuing Operations Before Income Taxes	56	62	139	25
Income Tax Expense From Continuing Operations	9	16	23	4
Net Income Attributable to Duke Energy Corporation	47	46	116	21
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Attributable to Duke Energy Corporation			116	21
Duke Energy Indiana [Member]
Operating Revenues
Total operating revenues	714	738	1,482	1,469
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	229	226	486	458
Operation, maintenance and other	188	197	377	378
Depreciation and amortization	132	126	263	256
Property and other taxes	20	20	39	40
Total operating expenses	569	569	1,165	1,132
Gains (Losses) on Sales of Other Assets and Other, net	3
Operating Income	148	169	317	337
Other Income and Expenses
Total other income and expenses	8	6	27	13
Interest Expense	28	43	71	83
Income From Continuing Operations Before Income Taxes	128	132	273	267
Income Tax Expense From Continuing Operations	31	34	66	69
Net Income Attributable to Duke Energy Corporation	97	98	207	198
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Attributable to Duke Energy Corporation			207	198
Piedmont Natural Gas [Member]
Operating Revenues
Total operating revenues	209	215	788	768
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	65	74	338	333
Operation, maintenance and other	83	85	163	167
Depreciation and amortization	42	39	84	78
Property and other taxes	13	12	25	24
Total operating expenses	203	210	610	602
Operating Income	6	5	178	166
Other Income and Expenses
Equity in earnings of unconsolidated affiliates			4	3
Total other income and expenses	6	4	12	9
Interest Expense	21	20	43	41
Income From Continuing Operations Before Income Taxes	(9)	(11)	147	134
Income Tax Expense From Continuing Operations	(2)	(3)	32	32
Net Income Attributable to Duke Energy Corporation	(7)	(8)	115	102
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Attributable to Duke Energy Corporation			115	102
Electricity, US Regulated [Member] | Duke Energy Ohio [Member]
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	86	93	179	185
Electricity, Nonregulated [Member] | Duke Energy Ohio [Member]
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas		14		29
Electricity [Member]
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	1,641	1,574	3,250	3,250
Natural Gas [Member]
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	76	89	403	402
Natural Gas [Member] | Duke Energy Ohio [Member]
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	$ 10	$ 15	$ 64	$ 69

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Net Income	$ 748	$ 502	$ 1,641	$ 1,124
Other Comprehensive (Loss) Income, net of tax
Pension and OPEB adjustments	3	1	3	2
Net unrealized (losses) gains on cash flow hedges	(29)	1	(46)	13
Reclassification into earnings from cash flow hedges	2	(2)	3	(1)
Unrealized gains (losses) on available-for-sale securities	4	(2)	8	(5)
Other Comprehensive (Loss) Income, net of tax	(20)	(2)	(32)	9
Comprehensive Income	728	500	1,609	1,133
Less: Comprehensive (Loss) Income Attributable to Noncontrolling Interests	(84)	2	(91)	4
Less: Preferred Dividends	12		12
Comprehensive Income Attributable to Duke Energy Corporation	$ 800	$ 498	$ 1,688	$ 1,129

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Current Assets
Cash and cash equivalents	$ 336	$ 442
Receivables (net of allowance for doubtful accounts)	646	962
Receivables of VIEs (net of allowance for doubtful accounts)	2,153	2,172
Inventory	3,189	3,084
Regulatory assets (includes amounts related to VIEs)	1,918	2,005
Other (includes amounts related to VIEs)	1,267	1,049
Total current assets	9,509	9,714
Property, Plant and Equipment
Cost	141,363	134,458
Accumulated depreciation and amortization	(44,482)	(43,126)
Generation facilities to be retired, net	317	362
Net property, plant and equipment	97,198	91,694
Operating lease right-of-use assets, net	1,735
Other Noncurrent Assets
Goodwill	19,303	19,303
Regulatory assets	13,393	13,617
Nuclear decommissioning trust funds	7,621	6,720
Investments in equity method unconsolidated affiliates	1,715	1,409
Other (includes amounts related to VIEs)	2,975	2,935
Total other noncurrent assets	46,742	43,984
Total Assets	153,449	145,392
Current Liabilities
Accounts payable	2,512	3,487
Notes payable and commercial paper	3,793	3,410
Taxes accrued	521	577
Interest accrued	564	559
Current maturities of long-term debt (includes amounts related to VIEs)	2,698	3,406
Asset retirement obligations	739	919
Regulatory liabilities	600	598
Other	2,020	2,085
Total current liabilities	13,447	15,041
Long-Term Debt (includes amounts related to VIEs)	54,342	51,123
Operating lease liabilities	1,502
Other Noncurrent Liabilities
Deferred income taxes	8,532	7,806
Asset retirement obligations	11,889	9,548
Regulatory liabilities	15,294	14,834
Accrued pension and other post-retirement benefit costs	959	988
Investment tax credits	569	568
Other (includes amounts related to VIEs)	1,583	1,650
Total other noncurrent liabilities	40,328	35,394
Commitments and Contingencies
Equity
Preferred stock	973
Common stock	1	1
Additional paid-in capital	40,885	40,795
Retained earnings	3,502	3,113
Accumulated other comprehensive loss	(148)	(92)
Total Duke Energy Corporation stockholders' equity	45,213	43,817
Noncontrolling interests	119	17
Total equity	45,332	43,834
Total Liabilities and Equity	153,449	145,392
Duke Energy Carolinas [Member]
Current Assets
Cash and cash equivalents	15	33
Receivables (net of allowance for doubtful accounts)	164	219
Receivables of VIEs (net of allowance for doubtful accounts)	671	699
Receivables from affiliated companies	101	182
Inventory	1,025	948
Regulatory assets (includes amounts related to VIEs)	605	520
Other (includes amounts related to VIEs)	17	72
Total current assets	2,598	2,673
Property, Plant and Equipment
Cost	47,249	44,741
Accumulated depreciation and amortization	(16,047)	(15,496)
Net property, plant and equipment	31,202	29,245
Operating lease right-of-use assets, net	141
Other Noncurrent Assets
Regulatory assets	3,392	3,457
Nuclear decommissioning trust funds	4,059	3,558
Other (includes amounts related to VIEs)	1,085	1,027
Total other noncurrent assets	8,677	8,042
Total Assets	42,477	39,960
Current Liabilities
Accounts payable	640	988
Accounts payable to affiliated companies	189	230
Notes payable to affiliated companies	804	439
Taxes accrued	209	171
Interest accrued	106	102
Current maturities of long-term debt (includes amounts related to VIEs)	456	6
Asset retirement obligations	203	290
Regulatory liabilities	191	199
Other	499	571
Total current liabilities	3,297	2,996
Long-Term Debt (includes amounts related to VIEs)	10,208	10,633
Long-Term Debt Payable to Affiliated Companies	300	300
Operating lease liabilities	117
Other Noncurrent Liabilities
Deferred income taxes	3,779	3,689
Asset retirement obligations	5,139	3,659
Regulatory liabilities	6,392	5,999
Accrued pension and other post-retirement benefit costs	90	99
Investment tax credits	234	231
Other (includes amounts related to VIEs)	645	671
Total other noncurrent liabilities	16,396	14,348
Equity
Member's equity	12,283	11,689
Accumulated other comprehensive loss	(7)	(6)
Total member's equity	12,276	11,683
Total Liabilities and Equity	42,477	39,960
Progress Energy [Member]
Current Assets
Cash and cash equivalents	51	67
Receivables (net of allowance for doubtful accounts)	139	220
Receivables of VIEs (net of allowance for doubtful accounts)	998	909
Receivables from affiliated companies	49	168
Inventory	1,480	1,459
Regulatory assets (includes amounts related to VIEs)	1,024	1,137
Other (includes amounts related to VIEs)	107	125
Total current assets	3,848	4,085
Property, Plant and Equipment
Cost	52,758	50,260
Accumulated depreciation and amortization	(16,808)	(16,398)
Generation facilities to be retired, net	317	362
Net property, plant and equipment	36,267	34,224
Operating lease right-of-use assets, net	839
Other Noncurrent Assets
Goodwill	3,655	3,655
Regulatory assets	6,423	6,564
Nuclear decommissioning trust funds	3,562	3,162
Other (includes amounts related to VIEs)	982	974
Total other noncurrent assets	15,461	14,355
Total Assets	55,576	52,664
Current Liabilities
Accounts payable	720	1,172
Accounts payable to affiliated companies	235	360
Notes payable to affiliated companies	1,920	1,235
Taxes accrued	191	109
Interest accrued	226	246
Current maturities of long-term debt (includes amounts related to VIEs)	1,026	1,672
Asset retirement obligations	416	514
Regulatory liabilities	250	280
Other	863	821
Total current liabilities	5,847	6,409
Long-Term Debt (includes amounts related to VIEs)	18,023	17,089
Long-Term Debt Payable to Affiliated Companies	150	150
Operating lease liabilities	747
Other Noncurrent Liabilities
Deferred income taxes	4,141	3,941
Asset retirement obligations	5,777	4,897
Regulatory liabilities	5,191	5,049
Accrued pension and other post-retirement benefit costs	509	521
Other (includes amounts related to VIEs)	352	351
Total other noncurrent liabilities	16,717	14,759
Equity
Additional paid-in capital	9,143	9,143
Retained earnings	5,715	5,131
Accumulated other comprehensive loss	(21)	(20)
Total Duke Energy Corporation stockholders' equity	14,837	14,254
Noncontrolling interests	2	3
Total equity	14,839	14,257
Total Liabilities and Equity	55,576	52,664
Duke Energy Progress [Member]
Current Assets
Cash and cash equivalents	28	23
Receivables (net of allowance for doubtful accounts)	53	75
Receivables of VIEs (net of allowance for doubtful accounts)	518	547
Receivables from affiliated companies	40	23
Inventory	980	954
Regulatory assets (includes amounts related to VIEs)	572	703
Other (includes amounts related to VIEs)	34	62
Total current assets	2,225	2,387
Property, Plant and Equipment
Cost	33,288	31,459
Accumulated depreciation and amortization	(11,728)	(11,423)
Generation facilities to be retired, net	317	362
Net property, plant and equipment	21,877	20,398
Operating lease right-of-use assets, net	407
Other Noncurrent Assets
Regulatory assets	4,124	4,111
Nuclear decommissioning trust funds	2,833	2,503
Other (includes amounts related to VIEs)	586	612
Total other noncurrent assets	7,950	7,226
Total Assets	32,052	30,011
Current Liabilities
Accounts payable	315	660
Accounts payable to affiliated companies	182	278
Notes payable to affiliated companies	127	294
Taxes accrued	106	53
Interest accrued	110	116
Current maturities of long-term debt (includes amounts related to VIEs)	6	603
Asset retirement obligations	413	509
Regulatory liabilities	167	178
Other	395	408
Total current liabilities	1,821	3,099
Long-Term Debt (includes amounts related to VIEs)	8,893	7,451
Long-Term Debt Payable to Affiliated Companies	150	150
Operating lease liabilities	377
Other Noncurrent Liabilities
Deferred income taxes	2,181	2,119
Asset retirement obligations	5,203	4,311
Regulatory liabilities	4,150	3,955
Accrued pension and other post-retirement benefit costs	232	237
Investment tax credits	141	142
Other (includes amounts related to VIEs)	91	106
Total other noncurrent liabilities	12,375	10,870
Equity
Total member's equity	8,813	8,441
Total Liabilities and Equity	32,052	30,011
Duke Energy Florida [Member]
Current Assets
Cash and cash equivalents	16	36
Receivables (net of allowance for doubtful accounts)	84	143
Receivables of VIEs (net of allowance for doubtful accounts)	480	362
Receivables from affiliated companies	18	28
Inventory	499	504
Regulatory assets (includes amounts related to VIEs)	452	434
Other (includes amounts related to VIEs)	46	46
Total current assets	1,595	1,553
Property, Plant and Equipment
Cost	19,461	18,792
Accumulated depreciation and amortization	(5,073)	(4,968)
Net property, plant and equipment	14,388	13,824
Operating lease right-of-use assets, net	432
Other Noncurrent Assets
Regulatory assets	2,299	2,454
Nuclear decommissioning trust funds	729	659
Other (includes amounts related to VIEs)	311	311
Total other noncurrent assets	3,771	3,424
Total Assets	19,754	18,801
Current Liabilities
Accounts payable	403	511
Accounts payable to affiliated companies	62	91
Notes payable to affiliated companies	477	108
Taxes accrued	148	74
Interest accrued	70	75
Current maturities of long-term debt (includes amounts related to VIEs)	671	270
Asset retirement obligations	3	5
Regulatory liabilities	83	102
Other	461	406
Total current liabilities	2,378	1,642
Long-Term Debt (includes amounts related to VIEs)	6,542	7,051
Operating lease liabilities	370
Other Noncurrent Liabilities
Deferred income taxes	2,105	1,986
Asset retirement obligations	574	586
Regulatory liabilities	1,040	1,094
Accrued pension and other post-retirement benefit costs	248	254
Other (includes amounts related to VIEs)	104	93
Total other noncurrent liabilities	4,441	4,013
Equity
Member's equity	6,394	6,097
Accumulated other comprehensive loss	(1)	(2)
Total member's equity	6,393	6,095
Total Liabilities and Equity	19,754	18,801
Duke Energy Ohio [Member]
Current Assets
Cash and cash equivalents	8	21
Receivables (net of allowance for doubtful accounts)	80	102
Receivables from affiliated companies	50	114
Inventory	124	126
Regulatory assets (includes amounts related to VIEs)	47	33
Other (includes amounts related to VIEs)	32	24
Total current assets	341	420
Property, Plant and Equipment
Cost	9,776	9,360
Accumulated depreciation and amortization	(2,761)	(2,717)
Net property, plant and equipment	7,015	6,643
Operating lease right-of-use assets, net	22
Other Noncurrent Assets
Goodwill	920	920
Regulatory assets	545	531
Other (includes amounts related to VIEs)	46	41
Total other noncurrent assets	1,533	1,492
Total Assets	8,889	8,555
Current Liabilities
Accounts payable	257	316
Accounts payable to affiliated companies	78	78
Notes payable to affiliated companies	203	274
Taxes accrued	135	202
Interest accrued	31	22
Current maturities of long-term debt (includes amounts related to VIEs)	100	551
Asset retirement obligations	6	6
Regulatory liabilities	67	57
Other	76	74
Total current liabilities	953	1,580
Long-Term Debt (includes amounts related to VIEs)	2,384	1,589
Long-Term Debt Payable to Affiliated Companies	25	25
Operating lease liabilities	21
Other Noncurrent Liabilities
Deferred income taxes	872	817
Asset retirement obligations	83	87
Regulatory liabilities	802	840
Accrued pension and other post-retirement benefit costs	94	79
Other (includes amounts related to VIEs)	94	93
Total other noncurrent liabilities	1,966	1,916
Equity
Common stock	762	762
Additional paid-in capital	2,776	2,776
Retained earnings	23	(93)
Total Duke Energy Corporation stockholders' equity	3,561	3,445
Total Liabilities and Equity	8,889	8,555
Duke Energy Indiana [Member]
Current Assets
Cash and cash equivalents	12	24
Receivables (net of allowance for doubtful accounts)	49	52
Receivables from affiliated companies	83	122
Inventory	463	422
Regulatory assets (includes amounts related to VIEs)	130	175
Other (includes amounts related to VIEs)	42	35
Total current assets	779	830
Property, Plant and Equipment
Cost	15,831	15,443
Accumulated depreciation and amortization	(5,104)	(4,914)
Net property, plant and equipment	10,727	10,529
Operating lease right-of-use assets, net	60
Other Noncurrent Assets
Regulatory assets	1,038	982
Other (includes amounts related to VIEs)	203	194
Total other noncurrent assets	1,301	1,176
Total Assets	12,807	12,535
Current Liabilities
Accounts payable	224	200
Accounts payable to affiliated companies	66	83
Notes payable to affiliated companies	165	167
Taxes accrued	25	43
Interest accrued	59	58
Current maturities of long-term debt (includes amounts related to VIEs)	3	63
Asset retirement obligations	115	109
Regulatory liabilities	24	25
Other	120	107
Total current liabilities	801	855
Long-Term Debt (includes amounts related to VIEs)	3,570	3,569
Long-Term Debt Payable to Affiliated Companies	150	150
Operating lease liabilities	56
Other Noncurrent Liabilities
Deferred income taxes	1,084	1,009
Asset retirement obligations	604	613
Regulatory liabilities	1,693	1,722
Accrued pension and other post-retirement benefit costs	142	115
Investment tax credits	147	147
Other (includes amounts related to VIEs)	14	16
Total other noncurrent liabilities	3,740	3,622
Equity
Total member's equity	4,546	4,339
Total Liabilities and Equity	12,807	12,535
Piedmont Natural Gas [Member]
Current Assets
Receivables (net of allowance for doubtful accounts)	100	266
Receivables from affiliated companies	17	22
Notes receivable from affiliated companies	16
Inventory	33	70
Regulatory assets (includes amounts related to VIEs)	30	54
Other (includes amounts related to VIEs)	57	19
Total current assets	253	431
Property, Plant and Equipment
Cost	7,966	7,486
Accumulated depreciation and amortization	(1,620)	(1,575)
Net property, plant and equipment	6,346	5,911
Operating lease right-of-use assets, net	26
Other Noncurrent Assets
Goodwill	49	49
Regulatory assets	280	303
Investments in equity method unconsolidated affiliates	81	64
Other (includes amounts related to VIEs)	60	52
Total other noncurrent assets	496	468
Total Assets	7,095	6,810
Current Liabilities
Accounts payable	156	203
Accounts payable to affiliated companies	52	38
Notes payable to affiliated companies		198
Taxes accrued	23	84
Interest accrued	33	31
Current maturities of long-term debt (includes amounts related to VIEs)		350
Regulatory liabilities	67	37
Other	62	58
Total current liabilities	393	999
Long-Term Debt (includes amounts related to VIEs)	2,384	1,788
Operating lease liabilities	25
Other Noncurrent Liabilities
Deferred income taxes	593	551
Asset retirement obligations	19	19
Regulatory liabilities	1,174	1,181
Accrued pension and other post-retirement benefit costs	6	4
Other (includes amounts related to VIEs)	145	177
Total other noncurrent liabilities	1,962	1,932
Equity
Common stock	1,310	1,160
Retained earnings	1,046	931
Total Duke Energy Corporation stockholders' equity	2,356	2,091
Total Liabilities and Equity	$ 7,095	$ 6,810

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Allowance for doubtful accounts - receivables	$ 16	$ 16
Regulatory assets, current	1,918	2,005
Other, current assets	1,267	1,049
Regulatory assets, noncurrent	13,393	13,617
Other, noncurrent assets	2,975	2,935
Current maturities of long-term debt	2,698	3,406
Long-Term Debt	$ 54,342	$ 51,123
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	728,000,000	727,000,000
Preferred stock, par value (in usd per share)	$ 0.001
Preferred stock, depositary shares authorized	40,000,000
Preferred stock, depositary shares outstanding	40,000,000
Other	$ 1,583	$ 1,650
Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	55	55
Regulatory assets, current	52	52
Other, current assets	140	162
Regulatory assets, noncurrent	1,019	1,041
Other, noncurrent assets	289	261
Current maturities of long-term debt	232	227
Long-Term Debt	4,070	3,998
Other	222	212
Duke Energy Carolinas [Member]
Allowance for doubtful accounts - receivables	2	2
Regulatory assets, current	605	520
Other, current assets	17	72
Regulatory assets, noncurrent	3,392	3,457
Other, noncurrent assets	1,085	1,027
Current maturities of long-term debt	456	6
Long-Term Debt	10,208	10,633
Other	645	671
Duke Energy Carolinas [Member] | Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	7	7
Progress Energy [Member]
Allowance for doubtful accounts - receivables	6	5
Regulatory assets, current	1,024	1,137
Other, current assets	107	125
Regulatory assets, noncurrent	6,423	6,564
Other, noncurrent assets	982	974
Current maturities of long-term debt	1,026	1,672
Long-Term Debt	$ 18,023	$ 17,089
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	$ 352	$ 351
Progress Energy [Member] | Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	8	8
Regulatory assets, current	52	52
Other, current assets	31	39
Regulatory assets, noncurrent	1,019	1,041
Current maturities of long-term debt	54	53
Long-Term Debt	1,657	1,636
Duke Energy Progress [Member]
Allowance for doubtful accounts - receivables	2	2
Regulatory assets, current	572	703
Other, current assets	34	62
Regulatory assets, noncurrent	4,124	4,111
Other, noncurrent assets	586	612
Current maturities of long-term debt	6	603
Long-Term Debt	8,893	7,451
Other	91	106
Duke Energy Progress [Member] | Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	5	5
Duke Energy Florida [Member]
Allowance for doubtful accounts - receivables	3	3
Regulatory assets, current	452	434
Other, current assets	46	46
Regulatory assets, noncurrent	2,299	2,454
Other, noncurrent assets	311	311
Current maturities of long-term debt	671	270
Long-Term Debt	6,542	7,051
Other	104	93
Duke Energy Florida [Member] | Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	3	3
Regulatory assets, current	52	52
Other, current assets	31	39
Regulatory assets, noncurrent	1,019	1,041
Current maturities of long-term debt	54	53
Long-Term Debt	1,332	1,336
Duke Energy Ohio [Member]
Allowance for doubtful accounts - receivables	3	2
Regulatory assets, current	47	33
Other, current assets	32	24
Regulatory assets, noncurrent	545	531
Other, noncurrent assets	46	41
Current maturities of long-term debt	100	551
Long-Term Debt	$ 2,384	$ 1,589
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	$ 94	$ 93
Duke Energy Indiana [Member]
Allowance for doubtful accounts - receivables	2	2
Regulatory assets, current	130	175
Other, current assets	42	35
Regulatory assets, noncurrent	1,038	982
Other, noncurrent assets	203	194
Current maturities of long-term debt	3	63
Long-Term Debt	3,570	3,569
Other	14	16
Piedmont Natural Gas [Member]
Allowance for doubtful accounts - receivables	4	2
Regulatory assets, current	30	54
Other, current assets	57	19
Regulatory assets, noncurrent	280	303
Other, noncurrent assets	60	52
Current maturities of long-term debt		350
Long-Term Debt	$ 2,384	$ 1,788
Common stock, shares authorized	100	100
Common stock, shares outstanding	100	100
Other	$ 145	$ 177

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income	$ 1,641	$ 1,124
Net income (attributable to parent)	1,720	1,120
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	2,483	2,250
Equity component of AFUDC	(67)	(106)
Losses on sales of other assets	0	97
Impairment charges	4	215
Deferred income taxes	527	289
Equity in earnings of unconsolidated affiliates	(87)	(12)
Accrued pension and other post-retirement benefit costs	4	31
Contributions to qualified pension plans		(141)
Payments for asset retirement obligations	(336)	(245)
Payment for disposal of other assets		(105)
Other rate case adjustments		37
Provision for rate refunds	57	281
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	(11)	7
Receivables	304	(27)
Inventory	(110)	70
Other current assets	(265)	21
Increase (decrease) in
Accounts payable	(700)	(142)
Taxes accrued	(56)	(58)
Other current liabilities	(378)	(214)
Other assets	7	(112)
Other liabilities	39	42
Net cash provided by operating activities	3,056	3,302
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(5,465)	(4,375)
Contributions to equity method investments	(162)	(140)
Purchases of debt and equity securities	(2,316)	(1,908)
Proceeds from sales and maturities of debt and equity securities	2,302	1,866
Other	(147)	(88)
Net cash used in investing activities	(5,788)	(4,645)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	4,622	2,727
Proceeds from the issuance of preferred stock	973
Proceeds from the issuance of common stock	27	820
Payments for the redemption of long-term debt	(2,155)	(2,190)
Proceeds from the issuance of short-term debt with original maturities greater than 90 days	240	201
Payments for the redemption of short-term debt with original maturities greater than 90 days	(299)	(160)
Notes payable and commercial paper	383	1,090
Dividends paid	(1,312)	(1,199)
Other	143	(24)
Net cash provided by financing activities	2,622	1,265
Net decrease in cash, cash equivalents and restricted cash	(110)	(78)
Cash, cash equivalents and restricted cash at beginning of period	591	505
Cash, cash equivalents and restricted cash at end of period	481	427
Cash and cash equivalents at beginning of period	442
Cash and cash equivalents at end of period	336
Significant non-cash transactions:
Accrued capital expenditures	917	978
Non-cash dividends	54	52
Duke Energy Carolinas [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	594	440
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	804	707
Equity component of AFUDC	(21)	(39)
Losses on sales of other assets		1
Impairment charges	5	190
Deferred income taxes	54	90
Accrued pension and other post-retirement benefit costs	(4)	2
Contributions to qualified pension plans		(46)
Payments for asset retirement obligations	(131)	(114)
Provision for rate refunds	35	121
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	(8)	8
Receivables	83	(33)
Receivable from affiliated companies	81	(22)
Inventory	(77)	(16)
Other current assets	(133)	(33)
Increase (decrease) in
Accounts payable	(282)	(59)
Accounts payable to affiliated companies	(41)	(51)
Taxes accrued	38	(78)
Other current liabilities	(71)	(123)
Other assets	91	(6)
Other liabilities	(18)	(29)
Net cash provided by operating activities	999	910
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,357)	(1,270)
Purchases of debt and equity securities	(1,114)	(976)
Proceeds from sales and maturities of debt and equity securities	1,114	976
Other	(46)	(64)
Net cash used in investing activities	(1,403)	(1,334)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	25	991
Payments for the redemption of long-term debt	(3)	(702)
Notes payable to affiliated companies	365	636
Distributions to parent		(500)
Other	(1)	(1)
Net cash provided by financing activities	386	424
Net increase (decrease) in cash and cash equivalents	(18)
Cash and cash equivalents at beginning of period	33	16
Cash and cash equivalents at end of period	15	16
Significant non-cash transactions:
Accrued capital expenditures	252	343
Progress Energy [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income	577	504
Net income (attributable to parent)	577	500
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	1,061	945
Equity component of AFUDC	(31)	(52)
Losses on sales of other assets	1	(12)
Impairment charges		33
Deferred income taxes	126	240
Accrued pension and other post-retirement benefit costs	8	12
Contributions to qualified pension plans		(45)
Payments for asset retirement obligations	(183)	(108)
Other rate case adjustments		37
Provision for rate refunds	10	65
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	(1)	14
Receivables	(42)	(196)
Receivable from affiliated companies	119	28
Inventory	(26)	71
Other current assets	114	(214)
Increase (decrease) in
Accounts payable	(196)	15
Accounts payable to affiliated companies	(125)	(19)
Taxes accrued	82	80
Other current liabilities	(162)	(58)
Other assets	(83)	(186)
Other liabilities	17	4
Net cash provided by operating activities	1,266	1,158
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,988)	(1,727)
Purchases of debt and equity securities	(1,094)	(812)
Proceeds from sales and maturities of debt and equity securities	1,089	820
Notes receivable from affiliated companies		(69)
Other	(59)	(81)
Net cash used in investing activities	(2,052)	(1,869)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	1,295	989
Payments for the redemption of long-term debt	(1,188)	(635)
Notes payable to affiliated companies	685	347
Other	2	(3)
Net cash provided by financing activities	794	698
Net decrease in cash, cash equivalents and restricted cash	8	(13)
Cash, cash equivalents and restricted cash at beginning of period	112	87
Cash, cash equivalents and restricted cash at end of period	120	74
Cash and cash equivalents at beginning of period	67
Cash and cash equivalents at end of period	51
Significant non-cash transactions:
Accrued capital expenditures	278	366
Duke Energy Progress [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	372	316
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	634	565
Equity component of AFUDC	(28)	(26)
Losses on sales of other assets		(2)
Impairment charges		33
Deferred income taxes	26	53
Accrued pension and other post-retirement benefit costs	1	7
Contributions to qualified pension plans		(25)
Payments for asset retirement obligations	(166)	(89)
Other rate case adjustments		37
Provision for rate refunds	10	65
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	(5)	6
Receivables	58	(104)
Receivable from affiliated companies	(17)	2
Inventory	(26)	41
Other current assets	115	(111)
Increase (decrease) in
Accounts payable	(223)	(17)
Accounts payable to affiliated companies	(96)	(4)
Taxes accrued	53	26
Other current liabilities	(74)	(38)
Other assets		10
Other liabilities	21	13
Net cash provided by operating activities	655	758
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(1,115)	(996)
Purchases of debt and equity securities	(473)	(573)
Proceeds from sales and maturities of debt and equity securities	458	556
Other	(20)	(45)
Net cash used in investing activities	(1,150)	(1,058)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	1,270
Payments for the redemption of long-term debt	(602)
Notes payable to affiliated companies	(167)	300
Other	(1)	(2)
Net cash provided by financing activities	500	298
Net increase (decrease) in cash and cash equivalents	5	(2)
Cash and cash equivalents at beginning of period	23	20
Cash and cash equivalents at end of period	28	18
Significant non-cash transactions:
Accrued capital expenditures	112	172
Duke Energy Florida [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	297	271
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	423	374
Equity component of AFUDC	(2)	(26)
Losses on sales of other assets	1
Deferred income taxes	82	206
Accrued pension and other post-retirement benefit costs	5	3
Contributions to qualified pension plans		(20)
Payments for asset retirement obligations	(17)	(19)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	2	6
Receivables	(101)	(92)
Receivable from affiliated companies	10	(4)
Inventory	1	28
Other current assets	8	(114)
Increase (decrease) in
Accounts payable	27	34
Accounts payable to affiliated companies	(29)	(11)
Taxes accrued	74	81
Other current liabilities	(80)	(21)
Other assets	(81)	(196)
Other liabilities	(9)	(10)
Net cash provided by operating activities	611	490
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(873)	(731)
Purchases of debt and equity securities	(621)	(239)
Proceeds from sales and maturities of debt and equity securities	631	264
Notes receivable from affiliated companies		(110)
Other	(37)	(35)
Net cash used in investing activities	(900)	(851)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	25	989
Payments for the redemption of long-term debt	(136)	(635)
Notes payable to affiliated companies	369
Other	3	(1)
Net cash provided by financing activities	261	353
Net decrease in cash, cash equivalents and restricted cash	(28)	(8)
Cash, cash equivalents and restricted cash at beginning of period	75	53
Cash, cash equivalents and restricted cash at end of period	47	45
Cash and cash equivalents at beginning of period	36
Cash and cash equivalents at end of period	16
Significant non-cash transactions:
Accrued capital expenditures	166	194
Duke Energy Ohio [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	116	21
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	132	134
Equity component of AFUDC	(7)	(8)
Losses on sales of other assets		106
Deferred income taxes	45	(2)
Accrued pension and other post-retirement benefit costs		2
Payments for asset retirement obligations	(5)	(2)
Provision for rate refunds	3	19
(Increase) decrease in
Receivables	24	(7)
Receivable from affiliated companies	64	62
Inventory	2	9
Other current assets	(13)	24
Increase (decrease) in
Accounts payable	(44)	(34)
Accounts payable to affiliated companies		(15)
Taxes accrued	(67)	(63)
Other current liabilities	2	8
Other assets	(18)	(7)
Other liabilities	(15)	(18)
Net cash provided by operating activities	219	229
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(473)	(392)
Notes receivable from affiliated companies		14
Other	(31)	(43)
Net cash used in investing activities	(504)	(421)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	794
Payments for the redemption of long-term debt	(451)	(3)
Notes payable to affiliated companies	(71)	190
Net cash provided by financing activities	272	187
Net increase (decrease) in cash and cash equivalents	(13)	(5)
Cash and cash equivalents at beginning of period	21	12
Cash and cash equivalents at end of period	8	7
Significant non-cash transactions:
Accrued capital expenditures	93	70
Non-cash equity contribution from parent		106
Duke Energy Indiana [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	207	198
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	265	258
Equity component of AFUDC	(9)	(7)
Deferred income taxes	60	36
Accrued pension and other post-retirement benefit costs	2	3
Contributions to qualified pension plans		(8)
Payments for asset retirement obligations	(17)	(21)
Provision for rate refunds		49
(Increase) decrease in
Receivables	5	2
Receivable from affiliated companies	39	36
Inventory	(41)	(20)
Other current assets	48	(35)
Increase (decrease) in
Accounts payable	26	33
Accounts payable to affiliated companies	(17)	(19)
Taxes accrued	(18)	(41)
Other current liabilities	(13)	3
Other assets	(34)	20
Other liabilities	14	(21)
Net cash provided by operating activities	517	466
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(443)	(416)
Purchases of debt and equity securities	(14)	(34)
Proceeds from sales and maturities of debt and equity securities	11	13
Other	(21)	2
Net cash used in investing activities	(467)	(435)
CASH FLOWS FROM FINANCING ACTIVITIES
Payments for the redemption of long-term debt	(60)
Notes payable to affiliated companies	(2)	60
Distributions to parent		(75)
Other		(1)
Net cash provided by financing activities	(62)	(16)
Net increase (decrease) in cash and cash equivalents	(12)	15
Cash and cash equivalents at beginning of period	24	9
Cash and cash equivalents at end of period	12	24
Significant non-cash transactions:
Accrued capital expenditures	84	62
Piedmont Natural Gas [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	115	102
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	85	79
Deferred income taxes	40	4
Equity in earnings of unconsolidated affiliates	(4)	(3)
Accrued pension and other post-retirement benefit costs	(5)	(2)
Provision for rate refunds	9	27
(Increase) decrease in
Receivables	168	166
Receivable from affiliated companies	5	(4)
Inventory	37	28
Other current assets	(17)	74
Increase (decrease) in
Accounts payable	(70)	(32)
Accounts payable to affiliated companies	14	(12)
Taxes accrued	(61)	4
Other current liabilities	10	28
Other assets	(5)	2
Other liabilities	(1)	(2)
Net cash provided by operating activities	320	459
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(480)	(327)
Contributions to equity method investments	(16)
Notes receivable from affiliated companies	(16)	(77)
Other	(6)	(2)
Net cash used in investing activities	(518)	(406)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	596
Payments for the redemption of long-term debt	(350)
Notes payable to affiliated companies	(198)	(364)
Capital contributions from parent	150	300
Net cash provided by financing activities	198	(64)
Net increase (decrease) in cash and cash equivalents		(11)
Cash and cash equivalents at beginning of period		19
Cash and cash equivalents at end of period		8
Significant non-cash transactions:
Accrued capital expenditures	$ 115	$ 73

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Changes in Equity - USD ($) $ in Millions		Total		Preferred Stock [Member]	Common Stockholders' Equity [Member]		Common Stock [Member]	Additional Paid-in Capital [Member]		Retained Earnings [Member]		Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]		Net Unrealized (Losses) Gains on Available for Sale Securities [Member]		Pension and OPEB Adjustments [Member]		Noncontrolling Interest [Member]		Duke Energy Carolinas [Member]	Duke Energy Carolinas [Member]Member's Equity [Member]	Duke Energy Carolinas [Member]Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]	Progress Energy [Member]		Progress Energy [Member]Common Stockholders' Equity [Member]		Progress Energy [Member]Additional Paid-in Capital [Member]		Progress Energy [Member]Retained Earnings [Member]		Progress Energy [Member]Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]		Progress Energy [Member]Net Unrealized (Losses) Gains on Available for Sale Securities [Member]		Progress Energy [Member]Pension and OPEB Adjustments [Member]		Progress Energy [Member]Noncontrolling Interest [Member]		Duke Energy Progress [Member]	Duke Energy Florida [Member]		Duke Energy Florida [Member]Member's Equity [Member]		Duke Energy Florida [Member]Net Unrealized (Losses) Gains on Available for Sale Securities [Member]		Duke Energy Ohio [Member]	Duke Energy Ohio [Member]Common Stock [Member]	Duke Energy Ohio [Member]Additional Paid-in Capital [Member]	Duke Energy Ohio [Member]Retained Earnings [Member]	Duke Energy Indiana [Member]	Piedmont Natural Gas [Member]	Piedmont Natural Gas [Member]Common Stock [Member]	Piedmont Natural Gas [Member]Retained Earnings [Member]	Common Stock [Member]	Common Stock [Member]Common Stockholders' Equity [Member]	Common Stock [Member]Common Stock [Member]	Common Stock [Member]Additional Paid-in Capital [Member]	Preferred Stock [Member]		Preferred Stock [Member]Preferred Stock [Member]		Preferred Stock [Member]Common Stockholders' Equity [Member]
Beginning Balance at Dec. 31, 2017		$ 41,737			$ 41,739		$ 1	$ 38,792		$ 3,013		$ (10)		$ 12		$ (69)		$ (2)					$ 13,465		$ 13,468		$ 9,143		$ 4,350		$ (18)		$ 5		$ (12)		$ (3)
Beginning Balance, in shares at Dec. 31, 2017							700,000,000
Beginning Balance (member's equity) at Dec. 31, 2017																				$ 11,361	$ 11,368	$ (7)																	$ 7,949	$ 5,618		$ 5,614		$ 4						$ 4,121
Beginning Balance (parent) at Dec. 31, 2017																																														$ 3,163	$ 762	$ 2,670	$ (269)		$ 1,662	$ 860	$ 802
Net income (attributable to parent)		1,120																		440	440		500																316	271		271				21			21	198	102		102
Net Income		1,124																					504		500				500								4
Net income		1,124			1,120					1,120								4
Other comprehensive income (loss)		9			9							12		(5)		2				1		1	4		4						3		(1)		2					(1)				(1)
Stock issuances, shares																																																								12,000,000
Stock issuances																																																						$ 890	$ 890		$ 890
Common stock dividends		(1,251)			(1,251)					(1,251)										(500)	(500)																													(75)
Distributions to noncontrolling interest in subsidiaries		(1)																(1)					(1)														(1)
Other		7	[1]		0	[1]				12	[1]			(12)	[1]			7	[1]						0	[2]	0	[2]	5	[2]			(5)	[2]						0	[3]	5	[3]	(5)	[3]	106		106			300	300
Distributions to noncontrolling interest in subsidiaries		(1)																(1)					(1)														(1)
Ending Balance at Jun. 30, 2018		42,515			42,507		$ 1	39,682		2,894		2		(5)		(67)		8					13,972		13,972		9,143		4,855		(15)		(1)		(10)
Ending Balance, in shares at Jun. 30, 2018							712,000,000
Ending Balance (member's equity) at Jun. 30, 2018																				11,302	11,308	(6)																	8,265	5,888		5,890		(2)						4,244
Ending Balance (parent) at Jun. 30, 2018																																														3,290	762	2,776	(248)		2,064	1,160	904
Beginning Balance at Mar. 31, 2018		41,798			41,792		$ 1	38,839		3,021		3		(4)		(68)		6					13,703		13,704		9,142		4,591		(16)		(1)		(12)		(1)
Beginning Balance, in shares at Mar. 31, 2018							701,000,000
Beginning Balance (member's equity) at Mar. 31, 2018																				11,435	11,441	(6)																	8,126	5,721		5,723		(2)						4,221
Beginning Balance (parent) at Mar. 31, 2018																																														3,138	762	2,670	(294)		1,772	860	912
Net income (attributable to parent)		500																		117	117		265																139	168		168				46			46	98	(8)		(8)
Net Income		502																					267		265				265								2
Net income		502			500					500								2
Other comprehensive income (loss)		(2)			(2)							(1)		(2)		1							2		2						1		(1)		2					(1)				(1)
Stock issuances, shares																																																								11,000,000
Stock issuances																																																						843	843		843
Common stock dividends		(626)			(626)					(626)										(250)	(250)																													(75)
Distributions to noncontrolling interest in subsidiaries																							(1)														(1)
Other		0			0					(1)				1									1	[2]	1	[2]	1	[2]	(1)	[2]			1	[2]						0	[3]	(1)	[3]	1	[3]	106		106			300	300
Distributions to noncontrolling interest in subsidiaries																							(1)														(1)
Ending Balance at Jun. 30, 2018		42,515			42,507		$ 1	39,682		2,894		2		(5)		(67)		8					13,972		13,972		9,143		4,855		(15)		(1)		(10)
Ending Balance, in shares at Jun. 30, 2018							712,000,000
Ending Balance (member's equity) at Jun. 30, 2018																				11,302	11,308	(6)																	8,265	5,888		5,890		(2)						4,244
Ending Balance (parent) at Jun. 30, 2018																																														$ 3,290	762	2,776	(248)		$ 2,064	1,160	904
Beginning Balance at Dec. 31, 2018		$ 43,834		$ 0	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					727,000,000																100																							90,000,000					100
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		$ 43,817																					$ 14,254																							$ 3,445	762	2,776	(93)		$ 2,091	1,160	931
Net income (attributable to parent)		1,720																		594	594		577																372	297		297				$ 116			116	207	115		115
Net Income		1,641																					577		577				577								0
Net income		1,629			1,720					1,720								(91)
Other comprehensive income (loss)		(32)			(32)							(43)		8		3							6		6						3		1		2					1				1
Stock issuances, shares																																																								1,000,000				40,000,000
Stock issuances																																																						89	89		89	$ 973	[4]	$ 973	[4]	$ 973	[4]
Common stock dividends		(1,354)			(1,354)					(1,354)
Distributions to noncontrolling interest in subsidiaries		(1)																(1)
Other		1	[5]		0	[5]		1	[5]	23	[5]	(6)	[5]	(1)	[5]	(17)	[5]	1	[5]	(1)		(1)	(1)	[6]					7	[6]	(4)	[6]	0	[6]	(3)	[6]	(1)	[6]													$ 150	150
Distributions to noncontrolling interest in subsidiaries		(1)																(1)
Contribution from noncontrolling interest in subsidiaries	[7]	193																193
Ending Balance at Jun. 30, 2019		$ 45,332		973	45,213		$ 1	40,885		3,502		(63)		4		(89)		119					$ 14,839		14,837		9,143		5,715		(13)				(8)		2
Ending Balance, in shares at Jun. 30, 2019		40,000,000
Ending Balance, in shares at Jun. 30, 2019		728,000,000					728,000,000																100																							90,000,000					100
Ending Balance (member's equity) at Jun. 30, 2019																				12,276	12,283	(7)																	8,813	6,393		6,394		(1)						4,546
Ending Balance (parent) at Jun. 30, 2019		$ 45,213																					$ 14,837																							$ 3,561	762	2,776	23		$ 2,356	1,310	1,046
Beginning 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
Beginning Balance, in shares at Mar. 31, 2019							728,000,000
Beginning Balance (member's equity) at Mar. 31, 2019																				11,975	11,982	(7)																	8,644	6,192		6,193		(1)						4,449
Beginning Balance (parent) at Mar. 31, 2019																																														3,514	762	2,776	(24)		2,213	1,160	1,053
Net income (attributable to parent)		820																		301	301		328																169	201		201				$ 47			47	97	(7)		(7)
Net Income		748																					329		328				328								1
Net income		736			820					820								(84)
Other comprehensive income (loss)		(20)			(20)							(27)		4		3							3		3						1		$ 1		1
Stock issuances																																																						$ 61	$ 61		$ 61	$ (1)		$ (1)		$ (1)
Common stock dividends		(678)			(678)					(678)
Distributions to noncontrolling interest in subsidiaries		(1)																(1)
Other		(3)			1			1				0						(4)					(1)						1						(1)		(1)														$ 150	150
Distributions to noncontrolling interest in subsidiaries		(1)																(1)
Contribution from noncontrolling interest in subsidiaries		193																193
Ending Balance at Jun. 30, 2019		$ 45,332		$ 973	$ 45,213		$ 1	$ 40,885		$ 3,502		$ (63)		$ 4		$ (89)		$ 119					$ 14,839		$ 14,837		$ 9,143		$ 5,715		$ (13)				$ (8)		$ 2
Ending Balance, in shares at Jun. 30, 2019		40,000,000
Ending Balance, in shares at Jun. 30, 2019		728,000,000					728,000,000																100																							90,000,000					100
Ending Balance (member's equity) at Jun. 30, 2019																				$ 12,276	$ 12,283	$ (7)																	$ 8,813	$ 6,393		$ 6,394		$ (1)						$ 4,546
Ending Balance (parent) at Jun. 30, 2019		$ 45,213																					$ 14,837																							$ 3,561	$ 762	$ 2,776	$ 23		$ 2,356	$ 1,310	$ 1,046
[1]	Amounts in Retained Earnings and Accumulated Other Comprehensive (Loss) Income represent a cumulative-effect adjustment due to implementation of a new accounting standard related to Financial Instruments Classification and Measurement.
[2]	Amounts in Retained Earnings and Accumulated Other Comprehensive (Loss) Income represent a cumulative-effect adjustment due to implementation of a new accounting standard related to Financial Instruments Classification and Measurement.
[3]	Amounts in Member's Equity and Accumulated Other Comprehensive Income (Loss) represent a cumulative-effect adjustment due to implementation of a new accounting standard related to Financial Instruments Classification and Measurement.
[4]	Duke Energy issued 40 million depositary shares of preferred stock in the first quarter of 2019.
[5]	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.
[6]	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.
[7]	Relates to tax equity financing activity in the Commercial Renewables segment.

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Changes in Equity (Parenthetical)	6 Months Ended
	Jun. 30, 2019shares
Preferred Stock [Member] | Preferred Stock [Member]
Stock issuances, shares	40,000,000

Organization and Basis of Prese

Organization and Basis of Presentation	6 Months Ended
	Jun. 30, 2019
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 17 18 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, 2018 . 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 13 for additional information on VIEs. These Condensed Consolidated Financial Statements also reflect the Duke Energy Registrants’ proportionate share of certain jointly owned generation and transmission facilities. NONCONTROLLING INTEREST Duke Energy maintains a controlling financial interest in certain less-than wholly owned non-regulated 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 HLBV method in allocating book profit 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 profit or loss allocated to each owner for the reporting period. During the second quarter of 2019, Duke Energy’s North Rosamond solar farm commenced commercial operations resulting in the allocation of losses to the noncontrolling tax equity members of $74 million utilizing the HLBV method. 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 13 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. June 30, 2019 December 31, 2018 Duke Duke Duke Progress Energy Duke Progress Energy Energy Energy Florida Energy Energy Florida Current Assets Cash and cash equivalents $ 336 $ 51 $ 16 $ 442 $ 67 $ 36 Other 106 31 31 141 39 39 Other Noncurrent Assets Other 39 38 — 8 6 — Total cash, cash equivalents and restricted cash $ 481 $ 120 $ 47 $ 591 $ 112 $ 75 INVENTORY Provisions for inventory write-offs were not material at June 30, 2019 , and December 31, 2018 . The components of inventory are presented in the tables below. June 30, 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 $ 2,252 $ 749 $ 1,036 $ 709 $ 327 $ 76 $ 323 $ 3 Coal 624 235 234 160 74 17 139 — Natural gas, oil and other fuel 313 41 210 111 98 31 1 30 Total inventory $ 3,189 $ 1,025 $ 1,480 $ 980 $ 499 $ 124 $ 463 $ 33 December 31, 2018 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 $ 2,238 $ 731 $ 1,049 $ 734 $ 315 $ 84 $ 312 $ 2 Coal 491 175 192 106 86 14 109 — Natural gas, oil and other fuel 355 42 218 114 103 28 1 68 Total inventory $ 3,084 $ 948 $ 1,459 $ 954 $ 504 $ 126 $ 422 $ 70 NEW ACCOUNTING STANDARDS Except as noted below, the new accounting standards adopted for 2018 and 2019 had no material impact on the presentation or results of operations, cash flows or financial position of the Duke Energy Registrants. Leases. In February 2016, the FASB issued revised accounting guidance for leases. The core principle of this guidance is that a lessee should recognize the assets and liabilities that arise from leases on the balance sheet. This resulted in a material impact on the presentation for the statement of financial position of the Duke Energy Registrants for the period ended June 30, 2019 , and an immaterial impact to the Duke Energy Registrants' results of operations for the three and six months ended June 30, 2019 , and cash flows for the six months ended June 30, 2019 . Duke Energy elected the modified retrospective method of adoption effective January 1, 2019. Under the modified retrospective method of adoption, prior year reported results are not restated. For adoption, Duke Energy has elected to apply the following practical expedients: Practical Expedient Description Package of transition practical expedients (for leases commenced prior to adoption date and must be adopted as a package) Do not need to 1) reassess whether any expired or existing contracts are/or contain leases, 2) reassess the lease classification for any expired or existing leases and 3) reassess initial direct costs for any existing leases. Short-term lease expedient (elect by class of underlying asset) Elect as an accounting policy to not apply the recognition requirements to short-term leases by asset class. Lease and non-lease components (elect by class of underlying asset) Elect as an accounting policy to not separate non-lease components from lease components and instead account for each lease and associated non-lease component as a single lease component by asset class. Hindsight expedient (when determining lease term) Elect to use hindsight to determine the lease term. Existing and expired land easements not previously accounted for as leases Elect to not evaluate existing or expired easements under the new guidance and carry forward current accounting treatment. Comparative reporting requirements for initial adoption Elect to apply transition requirements at adoption date, recognize cumulative effect adjustment to retained earnings in period of adoption and not apply the new requirements to comparative periods, including disclosures. Lessor expedient (elect by class of underlying asset) Elect as an accounting policy to aggregate non-lease components with the related lease component when specified conditions are met by asset class. Account for the combined component based on its predominant characteristic (revenue or operating lease). Duke Energy evaluated the financial statement impact of adopting the standard and monitored industry implementation issues. Under agreements considered leases, where Duke Energy is the lessee, for the use of certain aircraft, space on communication towers, industrial equipment, fleet vehicles, fuel transportation (barges and railcars), land, office space and PPAs are now recognized on the balance sheet. The Duke Energy Registrants did not have a material change to the financial statements from the adoption of the new standard for contracts where it is the lessor. See Note 5 for further information. No new accounting standards, issued but not yet adopted, are expected to have a material impact on the Duke Energy Registrants as of June 30, 2019 .

Business Segments

Business Segments	6 Months Ended
	Jun. 30, 2019
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. On April 24, 2019, Duke Energy executed an agreement to sell a minority interest in a portion of certain renewable assets. The portion of Duke Energy’s commercial renewables energy portfolio to be sold includes 49 percent of 37 operating wind, solar and battery storage assets and 33 percent of 11 operating solar assets across the U.S. The sale will result in pretax proceeds to Duke Energy of $415 million . Duke Energy will retain control of these assets, and, therefore, no gain or loss is expected to be recognized on the Condensed Consolidated Statements of Operations upon closing of the transaction. The sale is subject to customary closing conditions, including approvals from the FERC, the Public Utility Commission of Texas and the Committee on Foreign Investment in the U.S. Duke Energy received FERC approval on July 26, 2019. The transaction is expected to close in the second half of 2019. During the three months ended June 30, 2019, Duke Energy evaluated recoverability of its renewable merchant plants principally located in the Electric Reliability Council of Texas West market due to declining market pricing and declining long-term forecasted energy and capacity prices, primarily driven by lower forecasted natural gas prices. Duke Energy determined that the assets were not impaired because the carrying value of $160 million approximates the aggregate estimated future cash flows and further testing was not required. A continued decline in pricing would likely result in a future impairment. 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 NMC. Business segment information is presented in the following tables. Segment assets presented exclude intercompany assets. Three Months Ended June 30, 2019 Electric Gas Total Utilities and Utilities and Commercial Reportable (in millions) Infrastructure Infrastructure Renewables Segments Other Eliminations Total Unaffiliated revenues $ 5,467 $ 282 $ 118 $ 5,867 $ 6 $ — $ 5,873 Intersegment revenues 8 24 — 32 19 (51 ) — Total revenues $ 5,475 $ 306 $ 118 $ 5,899 $ 25 $ (51 ) $ 5,873 Segment income (loss) $ 809 $ 40 $ 86 $ 935 $ (115 ) $ — $ 820 Add back noncontrolling interests (a) (84 ) Add back preferred stock dividend 12 Net income $ 748 Segment assets $ 131,640 $ 12,943 $ 4,870 $ 149,453 $ 3,815 $ 181 $ 153,449 Three Months Ended June 30, 2018 Electric Gas Total Utilities and Utilities and Commercial Reportable (in millions) Infrastructure Infrastructure Renewables Segments Other Eliminations Total Unaffiliated revenues $ 5,215 $ 294 $ 119 $ 5,628 $ 15 $ — $ 5,643 Intersegment revenues 8 24 — 32 17 (49 ) — Total revenues $ 5,223 $ 318 $ 119 $ 5,660 $ 32 $ (49 ) $ 5,643 Segment income (loss) (b)(c) $ 575 $ 28 $ 38 $ 641 $ (136 ) $ — $ 505 Add back noncontrolling interests 2 Loss from discontinued operations, net of tax (5 ) Net income $ 502 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 June 30, 2019 Electric Gas Total Utilities and Utilities and Reportable (in millions) Infrastructure Infrastructure Segments Other Total Total revenues $ 336 $ 97 $ 433 $ — $ 433 Segment income/Net (loss) income $ 31 $ 17 $ 48 $ (1 ) $ 47 Segment assets $ 5,914 $ 2,948 $ 8,862 $ 27 $ 8,889 Three Months Ended June 30, 2018 Electric Gas Total Utilities and Utilities and Reportable (in millions) Infrastructure Infrastructure Segments Other Total Total revenues $ 346 $ 103 $ 449 $ 10 $ 459 Segment income/Net (loss) income $ 39 $ 18 $ 57 $ (11 ) $ 46 Six Months Ended June 30, 2019 Electric Gas Total Utilities and Utilities and Reportable (in millions) Infrastructure Infrastructure Segments Other Total Total revenues $ 691 $ 273 $ 964 $ — $ 964 Segment income/Net (loss) income $ 67 $ 52 $ 119 $ (3 ) $ 116 Six Months Ended June 30, 2018 Electric Gas Total Utilities and Utilities and Reportable (in millions) Infrastructure Infrastructure Segments Other Total Total revenues $ 682 $ 277 $ 959 $ 24 $ 983 Segment income/Net (loss) income (a) $ 72 $ 52 $ 124 $ (103 ) $ 21 (a) Other includes the loss on the sale of Beckjord described above.

Regulatory Matters

Regulatory Matters	6 Months Ended
	Jun. 30, 2019
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 Hurricane Florence, Hurricane Michael and Winter Storm Diego Deferral Filings On December 21, 2018, Duke Energy Carolinas and Duke Energy Progress filed with the NCUC petitions for approval to defer the incremental costs incurred in connection with the response to Hurricane Florence, Hurricane Michael and Winter Storm Diego to a regulatory asset for recovery in the next base rate case. The NCUC issued an order requesting comments on the deferral positions. On March 5, 2019, the North Carolina Public Staff (Public Staff) filed comments. On April 2, 2019, Duke Energy Carolinas and Duke Energy Progress filed reply comments, which included revised estimates of approximately $553 million in incremental operation and maintenance expenses ( $171 million and $382 million for Duke Energy Carolinas and Duke Energy Progress, respectively) and approximately $96 million in capital costs ( $20 million and $76 million for Duke Energy Carolinas and Duke Energy Progress, respectively). Duke Energy Carolinas and Duke Energy Progress cannot predict the outcome of this matter. Duke Energy Progress filed a similar request with the PSCSC on January 11, 2019, which also included a request for the continuation of prior deferrals requested for ice storms and Hurricane Matthew, and on January 30, 2019, the PSCSC issued a directive approving the deferral request, followed by an order issued on February 21, 2019. On March 15, 2019, Duke Energy Progress filed a request with FERC requesting permission to defer transmission-related storm costs that would be charged to wholesale transmission customers through Duke Energy Progress' Open Access Transmission Tariff (OATT) and to recover those costs from wholesale transmission customers over a three-year recovery period. FERC accepted the filing on May 14, 2019, which allows Duke Energy Progress to proceed with the proposed cost deferral and recovery. 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 percent increase in annual base revenues. The rate increase was driven by capital investments subsequent to the previous base rate case, including the W.S. Lee CC, 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 Lee 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 percent and a capital structure of 52 percent equity and 48 percent debt. As a result of the settlement, Duke Energy Carolinas recorded a pretax charge of approximately $4 million in the first quarter of 2018 to Operation, maintenance and other on the Condensed Consolidated Statements of Operations. On June 22, 2018, the NCUC issued an order approving the Stipulation of Partial Settlement and requiring a revenue reduction. As a result of the order, Duke Energy Carolinas recorded a pretax charge of approximately $150 million in the second quarter of 2018 to Impairment charges and Operation, maintenance and other on the Condensed Consolidated Statements of Operations. The charge was primarily related to the denial of a return on the Lee Nuclear Project and the assessment of a $70 million management penalty by reducing the annual recovery of deferred coal ash costs by $14 million per year over a five-year recovery period. On July 27, 2018, NCUC approved Duke Energy Carolinas' compliance filing. As a result, revised customer rates were effective on August 1, 2018. 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’s brief was filed on April 26, 2019. The Appellee response briefs are due on September 25, 2019. 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 represents an approximate 10.0 percent 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 percent. 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 provides that costs incurred after January 1, 2019, for the GIP will be deferred with a return, subject to evaluation in a future rate proceeding, and that Duke Energy Carolinas will 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. After hearings in March 2019, the PSCSC issued an order on May 21, 2019, which included a return on equity of 9.5 percent and a capital structure of 53 percent equity and 47 percent 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 percent; • 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 percent to be returned over a five-year period. As a result of the May 21, 2019 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. Duke Energy Carolinas awaits the order on reconsideration detailing the commission's decision. Based upon legal analysis and Duke Energy Carolinas' intention to file a notice of appeal with the South Carolina Supreme Court within 30 days of receipt of the order, Duke Energy Carolinas has not recorded an adjustment for its deferred coal ash costs. Duke Energy Carolinas cannot predict the outcome of this matter. FERC Formula Rate Matter On July 31, 2017, PMPA filed a complaint with FERC alleging that Duke Energy Carolinas misapplied the formula rate under the PPA between the parties by including in its rates amortization expense associated with regulatory assets and recorded in a certain account without FERC approval. On February 15, 2018, FERC issued an order ruling in favor of PMPA and ordered Duke Energy Carolinas to refund to PMPA all amounts improperly collected under the PPA. Duke Energy Carolinas has issued to PMPA and similarly situated wholesale customers refunds of approximately $25 million . FERC also set the matter for settlement and hearing. PMPA and other customers filed a protest to Duke Energy Carolinas' refund report claiming that the refunds are inadequate in that (1) Duke Energy Carolinas invoked the limitations periods in the contracts to limit the time period for which the refunds were paid and the customers disagree that this limitation applies, and (2) Duke Energy Carolinas refunded only amounts recovered through a certain account and the customers have asserted that the order applies to all regulatory assets. On July 3, 2018, FERC issued an order accepting Duke Energy Carolinas' refund report and ruling that these two claims are outside the scope of FERC's February order. The settlement agreements and revised formula rates for all parties to the proceeding were filed on December 28, 2018. On April 2, 2019, FERC issued an order approving the settlement agreement as filed. Since then, Duke Energy Carolinas has implemented the terms of the settlement in rates with all wholesale customers, including non-intervening customers. On July 25, 2019, Duke Energy Carolinas received FERC approval for the accounting treatment requested for certain assets included in the settlement agreements. This is the final approval needed from FERC and concludes this proceeding. Sale of Hydroelectric (Hydro) Plants In May 2018, Duke Energy Carolinas entered an agreement for the sale of five hydro plants with a combined 18.7-MW generation capacity in the Western Carolinas region to Northbrook Energy. The completion of the transaction is subject to approval from FERC for the four FERC-licensed plants, as well as other state regulatory agencies and is contingent upon regulatory approval from the NCUC and PSCSC to defer the total estimated loss on the sale of approximately $40 million . On July 5, 2018, Duke Energy Carolinas filed with NCUC for approval of the sale of the five hydro plants to Northbrook, to transfer the CPCNs for the four North Carolina hydro plants and to establish a regulatory asset for the North Carolina retail portion of the difference between sales proceeds and net book value. On June 5, 2019, the NCUC issued an order approving the transfer of the hydro plants from Duke Energy Carolinas to Northbrook, granting deferral accounting and denying the Public Staff's motion for reconsideration. On August 28, 2018, Duke Energy Carolinas filed with PSCSC an Application for Approval of Transfer and Sale of Hydroelectric Generation Facilities, Acceptance for Filing of a Power Purchase Agreement and an Accounting Order to Establish a Regulatory Asset. On September 10, 2018, the ORS provided a letter to the commission stating its position on the application and on September 18, 2018, Duke Energy Carolinas requested this matter be carried over to allow Duke Energy Carolinas time to discuss certain accounting issues with the ORS. At their June 26, 2019, agenda meeting, the PSCSC voted to approve the transfer and sale subject to the recommendation of the ORS that the issuance of an Accounting Order will not preclude the ORS, the commission or any other party from addressing the reasonableness of these costs, any return sought and including any carrying costs in the next rate case. On August 9, 2018, Duke Energy Carolinas and Northbrook filed a joint Application for Transfer of Licenses with the FERC. On December 27, 2018, the FERC issued its Order Approving Transfer of Licenses (“Order”) for the four FERC-licensed hydro plants. On January 18, 2019, Duke Energy Carolinas and Northbrook Carolina Hydro II, LLC requested a six-month extension of time to comply with the requirement of the Order that Northbrook submit to FERC certified copies of all instruments of conveyance and signed acceptance sheets within 60 days of the date of the Order. On February 14, 2019, FERC issued an order granting extensions until August 26, 2019, to comply with the requirements of the December 27, 2018 Order. The closing is expected to occur in 2019. After closing, Duke Energy Carolinas will purchase all the capacity and energy generated by these facilities at the avoided cost for five years through power purchase agreements. 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 percent increase in annual base revenues. Subsequent to the filing, Duke Energy Progress adjusted the requested amount to $420 million , representing an approximate 13 percent increase. The 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 percent and a capital structure of 52 percent equity and 48 percent debt. On February 23, 2018, the NCUC issued an order approving the stipulation. The order also impacted certain amounts that were similarly recorded on Duke Energy Carolinas' Condensed Consolidated Balance Sheets. As a result of the order, Duke Energy Progress and Duke Energy Carolinas recorded pretax charges of $68 million and $14 million , respectively, in the first quarter of 2018 to Impairment charges, Operation, maintenance and other and Interest Expense on the Condensed Consolidated Statements of Operations. Revised customer rates became effective on March 16, 2018. 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’s brief was filed on April 26, 2019. The Appellee response briefs are due on September 25, 2019. Duke Energy Progress cannot predict the outcome of this matter. 2018 South Carolina Rate Case On November 8, 2018, Duke Energy Progress filed an application with the PSCSC for a rate increase for retail customers of approximately $59 million , which represents an approximate 10.3 percent increase in annual base revenues. The rate increase is 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 percent. 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 provides that costs incurred after January 1, 2019, for the GIP will be deferred with a return, with all costs subject to evaluation in a future rate proceeding, and that Duke Energy Progress will 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. After hearings in April 2019, the PSCSC issued an order on May 21, 2019, which included a return on equity of 9.5 percent and a capital structure of 53 percent equity and 47 percent 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 percent; • 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 percent. 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. Duke Energy Progress awaits the order on reconsideration detailing the commission's decision. Based upon legal analysis and Duke Energy Progress' intention to file a notice of appeal with the South Carolina Supreme Court within 30 days of receipt of the order, 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. These investments will be made within the next seven years. Duke Energy Progress worked with the local natural gas distribution company to upgrade an existing natural gas pipeline to serve the natural gas plant. The lease became effective on March 2, 2019. On March 28, 2016, the NCUC issued an order approving a CPCN for the new combined-cycle natural gas plants, but denying the CPCN for the contingent simple cycle unit without prejudice to Duke Energy Progress to refile for approval in the future. On March 28, 2019, Duke Energy Progress filed an annual progress report for the construction of the combined-cycle plants with the NCUC, with an estimated cost of $893 million . Site preparation activities for the combined-cycle plants are complete and construction of these plants began in 2017, with an expected in-service date in late 2019. 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 and the Public Staff filed a Joint Proposed Order. On May 10, 2019, the NCUC issued an Order Granting Certificate of Public Convenience and Necessity with Conditions. The carrying value of the 376 -MW Asheville coal-fired plant, including associated ash basin closure costs, of $284 million and $327 million is included in Generation facilities to be retired, net on Duke Energy Progress' Condensed Consolidated Balance Sheets as of June 30, 2019 , and December 31, 2018 , respectively. Duke Energy Progress' request for a regulatory asset at the time of retirement with amortization over a 10 -year period was approved by the NCUC on February 23, 2018. Duke Energy Florida Storm Restoration Cost Recovery In September 2017, Duke Energy Florida’s service territory suffered significant damage from Hurricane Irma, resulting in approximately 1 million customers experiencing outages. In the fourth quarter of 2017, Duke Energy Florida also incurred preparation costs related to Hurricane Nate. On December 28, 2017, Duke Energy Florida filed a petition with the FPSC to recover incremental storm restoration costs for Hurricane Irma and Hurricane Nate and to replenish the storm reserve. On February 6, 2018, the FPSC approved a stipulation that would apply tax savings resulting from the Tax Act toward storm costs effective January 2018 in lieu of implementing a storm surcharge. On May 31, 2018, Duke Energy Florida filed a petition for approval of actual storm restoration costs and associated recovery process related to Hurricane Irma and Hurricane Nate. The petition sought the approval for the recovery in the amount of $510 million in actual recoverable storm restoration costs, including the replenishment of Duke Energy Florida’s storm reserve of $132 million , and the process for recovering these recoverable storm costs. On August 20, 2018, the FPSC approved Duke Energy Florida's unopposed Motion for Continuance filed August 17, 2018, to allow for an evidentiary hearing in this matter. On January 28, 2019, Duke Energy Florida made a supplemental filing to reduce the total storm cost recovery from $510 million to $508 million . On April 3, 2019, the FPSC issued an Order abating all remaining filing dates. On April 9, 2019, Duke Energy Florida filed an unopposed motion to approve a settlement agreement resolving all outstanding issues in this docket. On June 13, 2019, the FPSC issued its order approving the settlement agreement. The Storm Cost Settlement Agreement obligates Duke Energy Florida to capitalize $18 million of storm costs and remove $6 million of operating and maintenance expense, thereby reducing the requested storm cost recovery amount by $24 million . Duke Energy Florida will also implement process changes with respect to storm cost restoration. At June 30, 2019, and December 31, 2018, Duke Energy Florida's Condensed Consolidated Balance Sheets included approximately $118 million and $217 million , respectively, of recoverable costs under the FPSC's storm rule in Regulatory assets within Current Assets and Other Noncurrent Assets related to storm recovery for Hurricane Irma and Hurricane Nate. In October 2018, Duke Energy Florida’s service territory suffered damage when Hurricane Michael made landfall as a Category 5 hurricane with maximum sustained winds of 160 mph. The storm caused catastrophic damage from wind and storm surge, particularly from Panama City Beach to Mexico Beach, resulting in widespread outages and significant damage to transmission and distribution facilities across the central Florida Panhandle. In response to Hurricane Michael, Duke Energy Florida restored service to approximately 72,000 customers. Total current estimated incremental operation and maintenance and capital costs are $360 million . Approximately $82 million and $35 million of the costs are included in Net property, plant and equipment on the Condensed Consolidated Balance Sheets as of June 30, 2019, and December 31, 2018, respectively. Approximately $225 million and $165 million of costs are included in Regulatory assets within Other Noncurrent Assets on the Condensed Consolidated Balance Sheets as of June 30, 2019, and December 31, 2018, respectively, representing recoverable costs under the FPSC’s storm rule and Duke Energy Florida's OATT formula rates. Additional costs could be incurred in 2019 related to this fourth quarter 2018 storm. Duke Energy Florida filed a petition with the FPSC on April 30, 2019, to recover the retail portion of incremental storm restoration costs for Hurricane Michael. The estimated recovery amount is approximately $221 million . On June 11, 2019, the FPSC approved the petition for recovery of incremental storm restoration costs related to Hurricane Michael. The FPSC also approved the stipulation Duke Energy Florida filed, which will allow Duke Energy Florida to use the tax savings resulting from the Tax Act to recover these storm costs in lieu of implementing a storm surcharge. Approved storm costs are currently expected to be fully recovered by approximately year-end 2021. Duke Energy Florida expects to file actual costs for approval with the FPSC in 2019. Duke Energy Florida cannot predict the outcome of this matter. Tax Act Pursuant to Duke Energy Florida's 2017 Settlement, on May 31, 2018, Duke Energy Florida filed a petition related to the Tax Act, which included revenue requirement impacts of annual tax savings of $134 million and estimated annual amortization of EDIT of $67 million for a total of $201 million . Of this amount, $50 million would be offset by accelerated depreciation of Crystal River 4 and 5 coal units and an estimated $151 million would be offset by Hurricane Irma storm cost recovery as explained in the Storm Restoration Cost Recovery section above. On December 27, 2018, Duke Energy Florida filed actual EDIT balances and amortization based on its 2017 filed tax return. This increased the revenue requirement impact of the amortization of EDIT by $4 million , from $67 million to $71 million , which increased the total storm amortization from $151 million to $155 million . On January 8, 2019, the FPSC approved a joint motion by Duke Energy Florida and the Office of Public Counsel resolving all stipulated positions. As part of that stipulation, Duke Energy Florida agreed to seek a Private Letter Ruling (PLR) from the IRS on its treatment of cost of removal (COR) as mostly protected by tax normalization rules. If the IRS rules that COR is not protected by tax normalization rules, then Duke Energy Florida will make a final adjustment to the amortization of EDIT and an adjustment to the storm recovery amount retroactive to January 2018. The IRS has communicated that it will not issue individual PLRs on the treatment of COR. Rather, the IRS is drafting a notice that will request comments on a number of

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2019
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 tables contain 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. Six Months Ended June 30, 2019 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 $ 77 $ 11 $ 11 $ 4 $ 6 $ 48 $ 5 $ 2 Provisions/adjustments 9 4 3 2 1 2 — — Cash reductions (22 ) (3 ) (1 ) (1 ) — (18 ) — — Balance at end of period $ 64 $ 12 $ 13 $ 5 $ 7 $ 32 $ 5 $ 2 Six Months Ended June 30, 2018 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 $ 81 $ 10 $ 15 $ 3 $ 12 $ 47 $ 5 $ 2 Provisions/adjustments 1 2 2 2 (1 ) (3 ) 1 — Cash reductions (14 ) (1 ) (2 ) (1 ) (1 ) (9 ) (1 ) — Balance at end of period $ 68 $ 11 $ 15 $ 4 $ 10 $ 35 $ 5 $ 2 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 $ 51 Duke Energy Carolinas 12 Duke Energy Ohio 29 Piedmont 2 LITIGATION Duke Energy Carolinas and Duke Energy Progress NCDEQ Closure Litigation The Coal Ash Act requires CCR surface impoundments in North Carolina to be closed, with the closure method and timing based on a risk ranking classification determined by legislation or state regulators. The NCDEQ previously classified the impoundments at Allen, Belews Creek, Rogers, Marshall, Mayo and Roxboro as low risk and Duke Energy expected to close those sites through a combination of a cap system and a groundwater monitoring system. However, on April 1, 2019, NCDEQ issued a closure determination (NCDEQ's April 1 Order) requiring Duke Energy Carolinas and Duke Energy Progress to excavate all remaining coal ash impoundments at these facilities. On April 26, 2019, Duke Energy Carolinas and Duke Energy Progress filed Petitions for Contested Case Hearings in the Office of Administrative Hearings to challenge NCDEQ's April 1 Order. On May 9, 2019, NCDEQ issued a supplemental order requiring that closure plans be submitted on December 31, 2019, but providing that the corrective action plans are not due until March 31, 2020. Duke Energy Carolinas and Duke Energy Progress filed amended petitions on May 24, 2019, incorporating the May 9, 2019 order. On June 14, 2019, NCDEQ filed a motion to dismiss several claims in Duke Energy Carolinas' and Duke Energy Progress' appeals. On August 2, 2019, the court entered an order granting NCDEQ's motion to dismiss several of the claims. The lawsuit will proceed on the remaining issues, including whether the NCDEQ's decision was arbitrary and capricious. Duke Energy Carolinas and Duke Energy Progress cannot predict the outcome of this matter. 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. On May 14, 2019, the court granted an extension of stay, until September 15, 2019, to allow the parties to discuss potential resolution. If the case is not fully resolved at that time, litigation will resume. The trial is now scheduled for February 2021. Duke Energy Carolinas and Duke Energy Progress cannot predict the outcome of this matter. NCDEQ State Enforcement Actions In the first quarter of 2013, the SELC sent notices of intent to sue Duke Energy Carolinas and Duke Energy Progress related to alleged CWA violations from coal ash basins at two of their coal-fired power plants in North Carolina. The NCDEQ filed enforcement actions against Duke Energy Carolinas and Duke Energy Progress alleging violations of water discharge permits and North Carolina groundwater standards. The cases have been consolidated and are being heard before a single judge in the North Carolina Superior Court. On August 16, 2013, the NCDEQ filed an enforcement action against Duke Energy Carolinas and Duke Energy Progress related to their remaining plants in North Carolina, alleging violations of the CWA and violations of the North Carolina groundwater standards. Both of these cases have been assigned to the judge handling the enforcement actions discussed above. SELC is representing several environmental groups who have been permitted to intervene in these cases. The court issued orders in 2016 granting Motions for Partial Summary Judgment for seven of the 14 North Carolina plants named in the enforcement actions. On February 13, 2017, the court issued an order denying motions for partial summary judgment brought by both the environmental groups and Duke Energy Carolinas and Duke Energy Progress for the remaining seven plants. On March 15, 2017, Duke Energy Carolinas and Duke Energy Progress filed a Notice of Appeal with the North Carolina Court of Appeals to challenge the trial court’s order. The parties were unable to reach an agreement at mediation in April 2017 and submitted briefs to the trial court on remaining issues to be tried. On August 1, 2018, the Court of Appeals dismissed the appeal and the matter is proceeding before the trial court. In light of the NCDEQ's April 1 Order, on April 29, 2019, the court decided to stay any activity in the case until August 2019, at which time the court will hold another status conference. Duke Energy Carolinas and Duke Energy Progress cannot predict the outcome of this matter. Federal Citizens Suits On June 13, 2016, the RRBA filed a federal citizen suit in the Middle District of North Carolina alleging unpermitted discharges to surface water and groundwater violations at the Mayo Plant. On August 19, 2016, Duke Energy Progress filed a Motion to Dismiss. On April 26, 2017, the court entered an order dismissing four of the claims in the federal citizen suit. Two claims relating to alleged violations of NPDES permit provisions survived the motion to dismiss, and Duke Energy Progress filed its response on May 10, 2017. Duke Energy Progress and RRBA each filed motions for summary judgment on March 23, 2018. The court has not yet ruled on these motions. On May 16, 2017, RRBA filed a federal citizen suit in the U.S. District Court for the Middle District of North Carolina, which asserts two claims relating to alleged violations of NPDES permit provisions at the Roxboro Plant and one claim relating to the use of nearby water bodies. Duke Energy Progress and RRBA each filed motions for summary judgment on April 17, 2018, and the court has not yet ruled on these motions. On May 8, 2018, on motion from Duke Energy Progress, the court ordered trial in both of the above matters to be consolidated. On April 5, 2019, Duke Energy Progress filed a motion to stay the case following the NCDEQ’s April 1 Order. On August 2, 2019, the court ordered that this case is stayed and shall remain stayed pending further order from the court. On December 5, 2017, various parties filed a federal citizen suit in the U.S. District Court for the Middle District of North Carolina for alleged violations at Duke Energy Carolinas' Belews Creek under the CWA. Duke Energy Carolinas' answer to the complaint was filed on August 27, 2018. On October 10, 2018, Duke Energy Carolinas filed Motions to Dismiss for lack of standing, Motion for Judgment on the Pleadings and Motion to Stay Discovery. On January 9, 2019, the court entered an order denying Duke Energy Carolinas' motion to stay discovery. There has been no ruling on the other pending motions. On April 5, 2019, Duke Energy Carolinas filed a motion to stay the case following the NCDEQ’s April 1 Order. On August 2, 2019, the court ordered that this case is stayed and shall remain stayed pending further order from the court. Duke Energy Carolinas and Duke Energy Progress cannot predict the outcome of these matters. 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 June 30, 2019 , there were 145 asserted claims for non-malignant cases with cumulative relief sought of up to $38 million , and 50 asserted claims for malignant cases with cumulative relief sought of up to $16 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 $607 million at June 30, 2019 , and $630 million at December 31, 2018 . 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 2038 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 2038 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 $764 million in excess of the self-insured retention. Receivables for insurance recoveries were $739 million at June 30, 2019 , and December 31, 2018 . 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 2020. Duke Energy Florida Fluor Contract Litigation On January 29, 2019, Fluor filed a breach of contract lawsuit in the U.S. District Court for the Middle District of Florida against Duke Energy Florida related to an EPC agreement for the combined-cycle natural gas plant in Citrus County, Florida. Fluor filed an amended complaint on February 13, 2019. Fluor’s multicount complaint seeks civil, statutory and contractual remedies related to Duke Energy Florida’s $67 million draw in early 2019, on Fluor’s letter of credit and offset of invoiced amounts. Duke Energy Florida moved to dismiss all counts of Fluor's amended complaint, and on April 16, 2019, the court dismissed Fluor's complaint without prejudice. On April 26, 2019, Fluor filed a second amended complaint. Duke Energy Florida is attempting to recover from Fluor $110 million in additional costs incurred by Duke Energy Florida. On August 1, 2019, Duke Energy Florida and Fluor reached a settlement to resolve the pending litigation and other outstanding issues related to completing the Citrus County combined-cycle plant. The terms of the settlement will not have a material impact on Duke Energy Florida's results of operations, cash flows or financial position. 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) June 30, 2019 December 31, 2018 Reserves for Legal Matters Duke Energy $ 64 $ 65 Duke Energy Carolinas 7 9 Progress Energy 55 54 Duke Energy Progress 14 12 Duke Energy Florida 24 24 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 unlimited 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.

Leases

Leases	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Leases	LEASES As described in Note 1, Duke Energy adopted the revised accounting guidance for Leases effective January 1, 2019, using the modified retrospective method of adoption, which does not require restatement of prior year reported results. Adoption of the new standard resulted in the recording of ROU assets and operating lease liabilities as follows: As of January 1, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont ROU assets $ 1,750 $ 153 $ 863 $ 407 $ 456 $ 23 $ 61 $ 26 Operating lease liabilities – current 205 28 96 35 61 1 4 4 Operating lease liabilities – noncurrent 1,504 127 766 371 395 22 58 25 As part of its operations, Duke Energy leases certain aircraft, space on communication towers, industrial equipment, fleet vehicles, fuel transportation (barges and railcars), land and office space under various terms and expiration dates. Additionally, Duke Energy Carolinas, Duke Energy Progress and Duke Energy Indiana have finance leases related to firm natural gas pipeline transportation capacity. Duke Energy Progress and Duke Energy Florida have entered into certain PPAs, which are classified as finance and operating leases. Duke Energy has certain lease agreements, which include variable lease payments that are based on the usage of an asset. These variable lease payments are not included in the measurement of the ROU assets or operating lease liabilities on the Condensed Consolidated Financial Statements. Certain Duke Energy lease agreements include options for renewal and early termination. The intent to renew a lease varies depending on the lease type and asset. Renewal options that are reasonably certain to be exercised are included in the lease measurements. The decision to terminate a lease early is dependent on various economic factors. No termination options have been included in any of the lease measurements. Duke Energy operates various renewable energy projects and sells the generated output to utilities, electric cooperatives, municipalities and commercial and industrial customers through long-term PPAs. In certain situations, these PPAs and the associated renewable energy projects qualify as operating leases. Rental income from these leases is accounted for as Nonregulated electric and other revenues in the Condensed Consolidated Statements of Operations. There are no minimum lease payments as all payments are contingent based on actual electricity generated by the renewable energy projects. Contingent lease payments were $72 million and $136 million for the three and six months ended June 30, 2019 , respectively. As of June 30, 2019 , renewable energy projects owned by Duke Energy and accounted for as operating leases had a cost basis of $3,344 million and accumulated depreciation of $661 million . These assets are principally classified as nonregulated electric generation and transmission assets. The following table presents the components of lease expense. Three Months Ended June 30, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Operating lease expense (a) $ 73 $ 11 $ 40 $ 17 $ 23 $ 3 $ 5 $ 2 Short-term lease expense (a) 6 2 4 2 2 1 — — Variable lease expense (a) 10 4 5 2 3 — — — Finance lease expense Amortization of leased assets (b) 29 1 5 1 4 1 — — Interest on lease liabilities (c) 20 3 13 10 3 — 1 — Total finance lease expense 49 4 18 11 7 1 1 — Total lease expense $ 138 $ 21 $ 67 $ 32 $ 35 $ 5 $ 6 $ 2 Six Months Ended June 30, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Operating lease expense (a) $ 145 $ 23 $ 82 $ 36 $ 46 $ 6 $ 10 $ 3 Short-term lease expense (a) 13 4 7 3 4 1 1 — Variable lease expense (a) 21 12 7 3 4 — — — Finance lease expense Amortization of leased assets (b) 56 2 8 2 6 1 — — Interest on lease liabilities (c) 37 7 19 14 5 — 1 — Total finance lease expense 93 9 27 16 11 1 1 — Total lease expense $ 272 $ 48 $ 123 $ 58 $ 65 $ 8 $ 12 $ 3 (a) Included in Operations, maintenance and other or, for barges and railcars, Fuel used in electric generation and purchased power on the Condensed Consolidated Statements of Operations. (b) Included in Depreciation and amortization on the Condensed Consolidated Statements of Operations. (c) Included in Interest Expense on the Condensed Consolidated Statements of Operations. The following table presents rental expense for operating leases, as reported under the old lease standard. These amounts are included in Operation, maintenance and other and Fuel used in electric generation and purchased power on the Condensed Consolidated Statements of Operations. (in millions) Year Ended December 31, 2018 Duke Energy $ 268 Duke Energy Carolinas 49 Progress Energy 143 Duke Energy Progress 75 Duke Energy Florida 68 Duke Energy Ohio 13 Duke Energy Indiana 21 Piedmont 11 The following table presents operating lease maturities and a reconciliation of the undiscounted cash flows to operating lease liabilities. Twelve Months Ended June 30, Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont 2020 $ 279 $ 33 $ 129 $ 51 $ 78 $ 2 $ 6 $ 5 2021 239 28 112 52 60 2 5 5 2022 199 19 94 40 54 2 4 5 2023 190 18 95 40 55 2 4 5 2024 178 15 96 41 55 2 4 5 Thereafter 1,055 61 513 306 207 22 65 7 Total operating lease payments 2,140 174 1,039 530 509 32 88 32 Less: present value discount (425 ) (30 ) (192 ) (117 ) (75 ) (10 ) (28 ) (3 ) Total operating lease liabilities (a) $ 1,715 $ 144 $ 847 $ 413 $ 434 $ 22 $ 60 $ 29 (a) Certain operating lease payments include renewal options that are reasonably certain to be exercised. The following table presents future minimum lease payments under operating leases, which at inception had a non-cancelable term of more than one year, as reported under the old lease standard. December 31, 2018 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont 2019 $ 239 $ 33 $ 97 $ 49 $ 48 $ 2 $ 6 $ 5 2020 219 29 90 46 44 2 5 5 2021 186 19 79 37 42 2 4 5 2022 170 19 76 34 42 2 4 5 2023 160 17 77 35 42 2 5 6 Thereafter 1,017 68 455 314 141 23 66 11 Total $ 1,991 $ 185 $ 874 $ 515 $ 359 $ 33 $ 90 $ 37 The following table presents finance lease maturities and a reconciliation of the undiscounted cash flows to finance lease liabilities. Twelve Months Ended June 30, Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Indiana 2020 $ 177 $ 19 $ 69 $ 44 $ 25 $ 1 2021 183 17 69 44 25 1 2022 180 14 69 44 25 1 2023 171 14 69 44 25 1 2024 172 14 64 44 20 1 Thereafter 847 191 560 547 13 28 Total finance lease payments 1,730 269 900 767 133 33 Less: amounts representing interest (708 ) (162 ) (483 ) (457 ) (26 ) (23 ) Total finance lease liabilities $ 1,022 $ 107 $ 417 $ 310 $ 107 $ 10 The following table presents future minimum lease payments under finance leases, as reported under the old lease standard. December 31, 2018 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana 2019 $ 170 $ 20 $ 45 $ 20 $ 25 $ 2 $ 1 2020 174 20 46 21 25 — 1 2021 177 15 45 20 25 — 1 2022 165 15 45 21 24 — 1 2023 165 15 45 21 24 — 1 Thereafter 577 204 230 209 21 — 27 Minimum annual payments 1,428 289 456 312 144 2 32 Less: amount representing interest (487 ) (180 ) (205 ) (175 ) (30 ) — (22 ) Total $ 941 $ 109 $ 251 $ 137 $ 114 $ 2 $ 10 The following tables contain additional information related to leases. June 30, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Classification Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Assets Operating Operating lease ROU assets, net $ 1,735 $ 141 $ 839 $ 407 $ 432 $ 22 $ 60 $ 26 Finance Net property, plant and equipment 1,013 122 423 309 114 — 10 — Total lease assets $ 2,748 $ 263 $ 1,262 $ 716 $ 546 $ 22 $ 70 $ 26 Liabilities Current Operating Other current liabilities $ 213 $ 27 $ 100 $ 36 $ 64 $ 1 $ 4 $ 4 Finance Current maturities of long-term debt 115 6 23 6 17 — — — Noncurrent Operating Operating lease liabilities 1,502 117 747 377 370 21 56 25 Finance Long-Term Debt 907 101 394 304 90 — 10 — Total lease liabilities $ 2,737 $ 251 $ 1,264 $ 723 $ 541 $ 22 $ 70 $ 29 Six Months Ended June 30, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Cash paid for amounts included in the measurement of lease liabilities (a) Operating cash flows from operating leases $ 136 $ 15 $ 60 $ 23 $ 37 $ 1 $ 3 $ 5 Operating cash flows from finance leases 37 7 19 14 5 — 1 — Financing cash flows from finance leases 56 2 8 2 6 1 — — Lease assets obtained in exchange for new lease liabilities (non-cash) Operating (b) $ 78 $ 2 $ 30 $ 30 $ — $ — $ — $ 1 Finance 175 — 175 175 — — — — (a) No amounts were classified as investing cash flows from operating leases for the six months ended June 30, 2019 . (b) Does not include ROU assets recorded as a result of the adoption of the new lease standard. June 30, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Weighted-average remaining lease term (years) Operating leases 11 9 10 12 9 18 19 6 Finance leases 16 19 17 18 12 — 27 — Weighted-average discount rate (a) Operating leases 3.9 % 3.7 % 3.8 % 3.8 % 3.7 % 4.2 % 4.1 % 3.6 % Finance leases 7.9 % 12.9 % 11.8 % 12.4 % 8.3 % — % 11.9 % — % (a) The discount rate is calculated using the rate implicit in a lease if it is readily determinable. Generally, the rate used by the lessor is not provided to Duke Energy and in these cases the incremental borrowing rate is used. Duke Energy will typically use its fully collateralized incremental borrowing rate as of the commencement date to calculate and record the lease. The incremental borrowing rate is influenced by the lessee’s credit rating and lease term and as such may differ for individual leases, embedded leases or portfolios of leased assets.
Leases	LEASES As described in Note 1, Duke Energy adopted the revised accounting guidance for Leases effective January 1, 2019, using the modified retrospective method of adoption, which does not require restatement of prior year reported results. Adoption of the new standard resulted in the recording of ROU assets and operating lease liabilities as follows: As of January 1, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont ROU assets $ 1,750 $ 153 $ 863 $ 407 $ 456 $ 23 $ 61 $ 26 Operating lease liabilities – current 205 28 96 35 61 1 4 4 Operating lease liabilities – noncurrent 1,504 127 766 371 395 22 58 25 As part of its operations, Duke Energy leases certain aircraft, space on communication towers, industrial equipment, fleet vehicles, fuel transportation (barges and railcars), land and office space under various terms and expiration dates. Additionally, Duke Energy Carolinas, Duke Energy Progress and Duke Energy Indiana have finance leases related to firm natural gas pipeline transportation capacity. Duke Energy Progress and Duke Energy Florida have entered into certain PPAs, which are classified as finance and operating leases. Duke Energy has certain lease agreements, which include variable lease payments that are based on the usage of an asset. These variable lease payments are not included in the measurement of the ROU assets or operating lease liabilities on the Condensed Consolidated Financial Statements. Certain Duke Energy lease agreements include options for renewal and early termination. The intent to renew a lease varies depending on the lease type and asset. Renewal options that are reasonably certain to be exercised are included in the lease measurements. The decision to terminate a lease early is dependent on various economic factors. No termination options have been included in any of the lease measurements. Duke Energy operates various renewable energy projects and sells the generated output to utilities, electric cooperatives, municipalities and commercial and industrial customers through long-term PPAs. In certain situations, these PPAs and the associated renewable energy projects qualify as operating leases. Rental income from these leases is accounted for as Nonregulated electric and other revenues in the Condensed Consolidated Statements of Operations. There are no minimum lease payments as all payments are contingent based on actual electricity generated by the renewable energy projects. Contingent lease payments were $72 million and $136 million for the three and six months ended June 30, 2019 , respectively. As of June 30, 2019 , renewable energy projects owned by Duke Energy and accounted for as operating leases had a cost basis of $3,344 million and accumulated depreciation of $661 million . These assets are principally classified as nonregulated electric generation and transmission assets. The following table presents the components of lease expense. Three Months Ended June 30, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Operating lease expense (a) $ 73 $ 11 $ 40 $ 17 $ 23 $ 3 $ 5 $ 2 Short-term lease expense (a) 6 2 4 2 2 1 — — Variable lease expense (a) 10 4 5 2 3 — — — Finance lease expense Amortization of leased assets (b) 29 1 5 1 4 1 — — Interest on lease liabilities (c) 20 3 13 10 3 — 1 — Total finance lease expense 49 4 18 11 7 1 1 — Total lease expense $ 138 $ 21 $ 67 $ 32 $ 35 $ 5 $ 6 $ 2 Six Months Ended June 30, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Operating lease expense (a) $ 145 $ 23 $ 82 $ 36 $ 46 $ 6 $ 10 $ 3 Short-term lease expense (a) 13 4 7 3 4 1 1 — Variable lease expense (a) 21 12 7 3 4 — — — Finance lease expense Amortization of leased assets (b) 56 2 8 2 6 1 — — Interest on lease liabilities (c) 37 7 19 14 5 — 1 — Total finance lease expense 93 9 27 16 11 1 1 — Total lease expense $ 272 $ 48 $ 123 $ 58 $ 65 $ 8 $ 12 $ 3 (a) Included in Operations, maintenance and other or, for barges and railcars, Fuel used in electric generation and purchased power on the Condensed Consolidated Statements of Operations. (b) Included in Depreciation and amortization on the Condensed Consolidated Statements of Operations. (c) Included in Interest Expense on the Condensed Consolidated Statements of Operations. The following table presents rental expense for operating leases, as reported under the old lease standard. These amounts are included in Operation, maintenance and other and Fuel used in electric generation and purchased power on the Condensed Consolidated Statements of Operations. (in millions) Year Ended December 31, 2018 Duke Energy $ 268 Duke Energy Carolinas 49 Progress Energy 143 Duke Energy Progress 75 Duke Energy Florida 68 Duke Energy Ohio 13 Duke Energy Indiana 21 Piedmont 11 The following table presents operating lease maturities and a reconciliation of the undiscounted cash flows to operating lease liabilities. Twelve Months Ended June 30, Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont 2020 $ 279 $ 33 $ 129 $ 51 $ 78 $ 2 $ 6 $ 5 2021 239 28 112 52 60 2 5 5 2022 199 19 94 40 54 2 4 5 2023 190 18 95 40 55 2 4 5 2024 178 15 96 41 55 2 4 5 Thereafter 1,055 61 513 306 207 22 65 7 Total operating lease payments 2,140 174 1,039 530 509 32 88 32 Less: present value discount (425 ) (30 ) (192 ) (117 ) (75 ) (10 ) (28 ) (3 ) Total operating lease liabilities (a) $ 1,715 $ 144 $ 847 $ 413 $ 434 $ 22 $ 60 $ 29 (a) Certain operating lease payments include renewal options that are reasonably certain to be exercised. The following table presents future minimum lease payments under operating leases, which at inception had a non-cancelable term of more than one year, as reported under the old lease standard. December 31, 2018 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont 2019 $ 239 $ 33 $ 97 $ 49 $ 48 $ 2 $ 6 $ 5 2020 219 29 90 46 44 2 5 5 2021 186 19 79 37 42 2 4 5 2022 170 19 76 34 42 2 4 5 2023 160 17 77 35 42 2 5 6 Thereafter 1,017 68 455 314 141 23 66 11 Total $ 1,991 $ 185 $ 874 $ 515 $ 359 $ 33 $ 90 $ 37 The following table presents finance lease maturities and a reconciliation of the undiscounted cash flows to finance lease liabilities. Twelve Months Ended June 30, Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Indiana 2020 $ 177 $ 19 $ 69 $ 44 $ 25 $ 1 2021 183 17 69 44 25 1 2022 180 14 69 44 25 1 2023 171 14 69 44 25 1 2024 172 14 64 44 20 1 Thereafter 847 191 560 547 13 28 Total finance lease payments 1,730 269 900 767 133 33 Less: amounts representing interest (708 ) (162 ) (483 ) (457 ) (26 ) (23 ) Total finance lease liabilities $ 1,022 $ 107 $ 417 $ 310 $ 107 $ 10 The following table presents future minimum lease payments under finance leases, as reported under the old lease standard. December 31, 2018 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana 2019 $ 170 $ 20 $ 45 $ 20 $ 25 $ 2 $ 1 2020 174 20 46 21 25 — 1 2021 177 15 45 20 25 — 1 2022 165 15 45 21 24 — 1 2023 165 15 45 21 24 — 1 Thereafter 577 204 230 209 21 — 27 Minimum annual payments 1,428 289 456 312 144 2 32 Less: amount representing interest (487 ) (180 ) (205 ) (175 ) (30 ) — (22 ) Total $ 941 $ 109 $ 251 $ 137 $ 114 $ 2 $ 10 The following tables contain additional information related to leases. June 30, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Classification Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Assets Operating Operating lease ROU assets, net $ 1,735 $ 141 $ 839 $ 407 $ 432 $ 22 $ 60 $ 26 Finance Net property, plant and equipment 1,013 122 423 309 114 — 10 — Total lease assets $ 2,748 $ 263 $ 1,262 $ 716 $ 546 $ 22 $ 70 $ 26 Liabilities Current Operating Other current liabilities $ 213 $ 27 $ 100 $ 36 $ 64 $ 1 $ 4 $ 4 Finance Current maturities of long-term debt 115 6 23 6 17 — — — Noncurrent Operating Operating lease liabilities 1,502 117 747 377 370 21 56 25 Finance Long-Term Debt 907 101 394 304 90 — 10 — Total lease liabilities $ 2,737 $ 251 $ 1,264 $ 723 $ 541 $ 22 $ 70 $ 29 Six Months Ended June 30, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Cash paid for amounts included in the measurement of lease liabilities (a) Operating cash flows from operating leases $ 136 $ 15 $ 60 $ 23 $ 37 $ 1 $ 3 $ 5 Operating cash flows from finance leases 37 7 19 14 5 — 1 — Financing cash flows from finance leases 56 2 8 2 6 1 — — Lease assets obtained in exchange for new lease liabilities (non-cash) Operating (b) $ 78 $ 2 $ 30 $ 30 $ — $ — $ — $ 1 Finance 175 — 175 175 — — — — (a) No amounts were classified as investing cash flows from operating leases for the six months ended June 30, 2019 . (b) Does not include ROU assets recorded as a result of the adoption of the new lease standard. June 30, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Weighted-average remaining lease term (years) Operating leases 11 9 10 12 9 18 19 6 Finance leases 16 19 17 18 12 — 27 — Weighted-average discount rate (a) Operating leases 3.9 % 3.7 % 3.8 % 3.8 % 3.7 % 4.2 % 4.1 % 3.6 % Finance leases 7.9 % 12.9 % 11.8 % 12.4 % 8.3 % — % 11.9 % — % (a) The discount rate is calculated using the rate implicit in a lease if it is readily determinable. Generally, the rate used by the lessor is not provided to Duke Energy and in these cases the incremental borrowing rate is used. Duke Energy will typically use its fully collateralized incremental borrowing rate as of the commencement date to calculate and record the lease. The incremental borrowing rate is influenced by the lessee’s credit rating and lease term and as such may differ for individual leases, embedded leases or portfolios of leased assets.

Debt and Credit Facilities

Debt and Credit Facilities	6 Months Ended
	Jun. 30, 2019
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). Six Months Ended June 30, 2019 Duke Duke Duke Maturity Interest Duke Energy Energy Energy Issuance Date Date Rate Energy (Parent) Progress Ohio Piedmont Unsecured Debt March 2019 (a) March 2022 3.251 % (b) $ 300 $ 300 $ — $ — $ — March 2019 (a) March 2022 3.227 % 300 300 — — — May 2019 (e) June 2029 3.500 % 600 — — — 600 June 2019 (a) June 2029 3.400 % 600 600 — — — June 2019 (a) June 2049 4.200 % 600 600 — — — First Mortgage Bonds January 2019 (c) February 2029 3.650 % 400 — — 400 — January 2019 (c) February 2049 4.300 % 400 — — 400 — March 2019 (d) March 2029 3.450 % 600 — 600 — — Total issuances $ 3,800 $ 1,800 $ 600 $ 800 $ 600 (a) Debt issued to pay down short-term debt 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 April 2019, pay down short-term debt and for general corporate purposes. (d) Debt issued to fund eligible green energy projects in the Carolinas. (e) Debt issued to repay in full the outstanding $350 million Piedmont unsecured term loan due September 2019, pay down short-term debt and for general corporate purposes. In June 2019, Duke Energy Kentucky priced $210 million of unsecured debentures of which $95 million carry a fixed interest rate of 3.23 percent and mature October 2025, $75 million carry a fixed interest rate of 3.56 percent and mature October 2029, and $40 million carry a fixed interest rate of 4.32 percent and mature July 2049. The $40 million tranche closed and funded in July 2019, and the remaining tranches are expected to close in September 2019 upon receipt of necessary regulatory approvals. The proceeds will be used to refinance Duke Energy Kentucky's $100 million , 4.65 percent debentures maturing October 2019, to pay down short-term intercompany debt and for general corporate purposes. CURRENT MATURITIES OF LONG-TERM DEBT The following table shows the significant components of Current Maturities of Long-Term Debt on the Condensed Consolidated Balance Sheets. The Duke Energy Registrants currently anticipate satisfying these obligations with cash on hand and proceeds from additional borrowings. (in millions) Maturity Date Interest Rate June 30, 2019 Unsecured Debt Duke Energy (Parent) September 2019 5.050 % $ 500 Duke Energy Kentucky October 2019 4.650 % 100 Progress Energy December 2019 4.875 % 350 Duke Energy (Parent) June 2020 2.100 % 330 First Mortgage Bonds Duke Energy Florida January 2020 1.850 % 250 Duke Energy Florida April 2020 4.550 % 250 Duke Energy Carolinas June 2020 4.300 % 450 Other (a) 468 Current maturities of long-term debt $ 2,698 (a) Includes finance lease obligations, amortizing debt and small bullet maturities. AVAILABLE CREDIT FACILITIES Master Credit Facility In March 2019, Duke Energy amended its existing $8 billion Master Credit Facility to extend the termination date to March 2024 . The Duke Energy Registrants, excluding Progress Energy (Parent), 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. The table below includes the current borrowing sublimits and available capacity under the Master Credit Facility. June 30, 2019 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 $ 1,750 $ 1,250 $ 800 $ 450 $ 600 $ 500 Reduction to backstop issuances Commercial paper (b) (3,420 ) (1,009 ) (1,099 ) (276 ) (474 ) (236 ) (326 ) — Outstanding letters of credit (53 ) (45 ) (4 ) (2 ) — — — (2 ) Tax-exempt bonds (81 ) — — — — — (81 ) — Coal ash set-aside (500 ) — (250 ) (250 ) — — — — Available capacity under the Master Credit Facility $ 3,946 $ 1,596 $ 397 $ 722 $ 326 $ 214 $ 193 $ 498 (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 June 30, 2019 (in millions) Facility size Amount drawn Duke Energy (Parent) Three-Year Revolving Credit Facility (a) $ 1,000 $ 500 Duke Energy Progress Term Loan Facility (b) 700 700 (a) In May 2019, Duke Energy (Parent) extended the termination date to May 2022. (b) $650 million was drawn under the term loan in January and February 2019. In May 2019, the $350 million Piedmont term loan was paid off in full with proceeds from the $600 million Piedmont debt offering.

Asset Retirement Obligations

Asset Retirement Obligations	6 Months Ended
	Jun. 30, 2019
Asset Retirement Obligation [Abstract]
Asset Retirement Obligations	ASSET RETIREMENT OBLIGATIONS The Duke Energy Registrants record AROs when there is a legal obligation to incur retirement costs associated with the retirement of a long-lived asset and the obligation can be reasonably estimated. Actual closure costs incurred could be materially different from current estimates that form the basis of the recorded AROs. The following table presents the AROs recorded on the Condensed Consolidated Balance Sheets. June 30, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Decommissioning of nuclear power facilities (a) $ 5,807 $ 2,401 $ 3,265 $ 2,739 $ 526 $ — $ — $ — Closure of ash impoundments 6,498 2,894 2,858 2,839 19 47 699 — Other 323 47 70 38 32 42 20 19 Total ARO $ 12,628 $ 5,342 $ 6,193 $ 5,616 $ 577 $ 89 $ 719 $ 19 Less: current portion 739 203 416 413 3 6 115 — Total noncurrent ARO $ 11,889 $ 5,139 $ 5,777 $ 5,203 $ 574 $ 83 $ 604 $ 19 (a) Duke Energy amount includes purchase accounting adjustments related to the merger with Progress Energy. ARO Liability Rollforward The following table presents the change in liability associated with AROs for the Duke Energy Registrants. 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, 2018 (a) $ 10,467 $ 3,949 $ 5,411 $ 4,820 $ 591 $ 93 $ 722 $ 19 Accretion expense (b) 245 111 124 111 13 2 14 — Liabilities settled (c) (404 ) (155 ) (225 ) (197 ) (28 ) (6 ) (17 ) — Revisions in estimates of cash flows (d) 2,320 1,437 883 882 1 — — — Balance at June 30, 2019 $ 12,628 $ 5,342 $ 6,193 $ 5,616 $ 577 $ 89 $ 719 $ 19 (a) Primarily relates to decommissioning nuclear power facilities, closure of ash impoundments, asbestos removal, closure of landfills at fossil generation facilities, retirement of natural gas mains and removal of renewable energy generation assets. (b) For the six months ended June 30, 2019 , substantially all accretion expense relates to Duke Energy's regulated operations and has been deferred in accordance with regulatory accounting treatment. (c) Primarily relates to ash impoundment closures. (d) Relates to increases in closure estimates for certain ash impoundments as a result of the NCDEQ's April 1 Order. See Note 4 for more information. The incremental amount recorded represents the discounted cash flows for estimated closure costs based upon the probability weightings of the potential closure methods as evaluated on a site-by-site basis. Asset retirement costs associated with the AROs for operating plants and retired plants are included in Net property, plant and equipment and Regulatory assets within Other Noncurrent Assets, respectively, on the Condensed Consolidated Balance Sheets. Nuclear Decommissioning Trust Funds Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida each maintain NDTFs that are intended to pay for the decommissioning costs of their respective nuclear power plants. The following table presents the fair value of NDTF assets legally restricted for purposes of settling AROs associated with nuclear decommissioning. Duke Energy Florida is actively decommissioning Crystal River Unit 3 and was granted an exemption from the NRC, which allows for use of the NDTF for all aspects of nuclear decommissioning. The entire balance of Duke Energy Florida's NDTF may be applied toward license termination, spent fuel and site restoration costs incurred to decommission Crystal River Unit 3 and is excluded from the table below. See Note 12 for additional information related to the fair value of the Duke Energy Registrants' NDTFs. (in millions) June 30, 2019 December 31, 2018 Duke Energy $ 6,327 $ 5,579 Duke Energy Carolinas 3,574 3,133 Duke Energy Progress 2,753 2,446

Goodwill

Goodwill	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 , and December 31, 2018 . 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 June 30, 2019 , and December 31, 2018 . 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	6 Months Ended
	Jun. 30, 2019
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 June 30, Six Months Ended June 30, (in millions) 2019 2018 2019 2018 Duke Energy Carolinas Corporate governance and shared service expenses (a) $ 197 $ 213 $ 409 $ 433 Indemnification coverages (b) 5 5 10 11 JDA revenue (c) 17 19 40 53 JDA expense (c) 20 19 113 73 Intercompany natural gas purchases (d) 3 4 7 8 Progress Energy Corporate governance and shared service expenses (a) $ 183 $ 206 $ 359 $ 397 Indemnification coverages (b) 10 9 19 17 JDA revenue (c) 20 19 113 73 JDA expense (c) 17 19 40 53 Intercompany natural gas purchases (d) 19 19 38 38 Duke Energy Progress Corporate governance and shared service expenses (a) $ 108 $ 126 $ 214 $ 244 Indemnification coverages (b) 4 3 8 6 JDA revenue (c) 20 19 113 73 JDA expense (c) 17 19 40 53 Intercompany natural gas purchases (d) 19 19 38 38 Duke Energy Florida Corporate governance and shared service expenses (a) $ 75 $ 80 $ 145 $ 153 Indemnification coverages (b) 6 6 11 11 Duke Energy Ohio Corporate governance and shared service expenses (a) $ 83 $ 90 $ 168 $ 179 Indemnification coverages (b) 1 1 2 2 Duke Energy Indiana Corporate governance and shared service expenses (a) $ 93 $ 96 $ 190 $ 197 Indemnification coverages (b) 1 2 3 4 Piedmont Corporate governance and shared service expenses (a) $ 37 $ 40 $ 69 $ 76 Indemnification coverages (b) — — 1 1 Intercompany natural gas sales (d) 22 23 45 46 Natural gas storage and transportation costs (e) 6 6 11 12 (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, Hardy Storage, and Cardinal 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 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 13 , 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 June 30, 2019 Intercompany income tax receivable $ — $ 25 $ — $ — $ 15 $ — $ 26 Intercompany income tax payable 76 — 41 19 — 1 — December 31, 2018 Intercompany income tax receivable $ 52 $ 47 $ 29 $ — $ — $ 8 $ — Intercompany income tax payable — — — 16 3 — 45

Derivatives and Hedging

Derivatives and Hedging	6 Months Ended
	Jun. 30, 2019
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 AOCI for the three and six months ended June 30, 2019 , and 2018 , 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. June 30, 2019 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Cash flow hedges $ 959 $ — $ — $ — $ — $ — Undesignated contracts 1,427 600 800 250 550 27 Total notional amount (a) $ 2,386 $ 600 $ 800 $ 250 $ 550 $ 27 December 31, 2018 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Cash flow hedges $ 923 $ — $ — $ — $ — $ — Undesignated contracts 1,721 300 1,200 650 550 27 Total notional amount (a) $ 2,644 $ 300 $ 1,200 $ 650 $ 550 $ 27 (a) Duke Energy includes amounts related to consolidated VIEs of $659 million in cash flow hedges as of June 30, 2019 , and $422 million in cash flow hedges and $194 million in undesignated contracts as of December 31, 2018 . 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. June 30, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Electricity (GWh) 33,135 — — — — 3,514 29,621 — Natural gas (millions of dekatherms) 740 133 173 173 — — 4 430 December 31, 2018 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Electricity (GWh) 15,286 — — — — 1,786 13,500 — Natural gas (millions of dekatherms) 739 121 169 166 3 — 1 448 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. The accelerated decommissioning of Crystal River Unit 3 is subject to the approval of the NRC and the FPSC. 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 June 30, 2019, the aggregate notional amount of both the put and call options was 305,000 units in U.S. equity security index funds. The derivative balances associated with these equity options are immaterial as of June 30, 2019. 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. 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 June 30, 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 $ 37 $ — $ — $ — $ — $ 7 $ 29 $ 2 Total Derivative Assets – Commodity Contracts $ 37 $ — $ — $ — $ — $ 7 $ 29 $ 2 Interest Rate Contracts Designated as Hedging Instruments Noncurrent 1 — — — — — — — Total Derivative Assets – Interest Rate Contracts $ 1 $ — $ — $ — $ — $ — $ — $ — Total Derivative Assets $ 38 $ — $ — $ — $ — $ 7 $ 29 $ 2 Derivative Liabilities June 30, 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 $ 64 $ 31 $ 24 $ 24 $ — $ — $ 2 $ 7 Noncurrent 140 8 24 9 — — — 107 Total Derivative Liabilities – Commodity Contracts $ 204 $ 39 $ 48 $ 33 $ — $ — $ 2 $ 114 Interest Rate Contracts Designated as Hedging Instruments Current $ 4 $ — $ — $ — $ — $ — $ — $ — Noncurrent 32 — — — — — — — Not Designated as Hedging Instruments Current 86 54 31 2 29 1 — — Noncurrent 16 — 11 — 10 5 — — Total Derivative Liabilities – Interest Rate Contracts $ 138 $ 54 $ 42 $ 2 $ 39 $ 6 $ — $ — Total Derivative Liabilities $ 342 $ 93 $ 90 $ 35 $ 39 $ 6 $ 2 $ 114 Derivative Assets December 31, 2018 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 $ 35 $ 2 $ 2 $ 2 $ — $ 6 $ 23 $ 3 Noncurrent 4 1 2 2 — — — — Total Derivative Assets – Commodity Contracts $ 39 $ 3 $ 4 $ 4 $ — $ 6 $ 23 $ 3 Interest Rate Contracts Designated as Hedging Instruments Current $ 1 $ — $ — $ — $ — $ — $ — $ — Noncurrent 3 — — — — — — — Not Designated as Hedging Instruments Current 2 — — — — — — — Noncurrent 12 — — — — — — — Total Derivative Assets – Interest Rate Contracts $ 18 $ — $ — $ — $ — $ — $ — $ — Total Derivative Assets $ 57 $ 3 $ 4 $ 4 $ — $ 6 $ 23 $ 3 Derivative Liabilities December 31, 2018 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 $ 33 $ 14 $ 10 $ 5 $ 6 $ — $ — $ 8 Noncurrent 158 10 15 6 — — — 133 Total Derivative Liabilities – Commodity Contracts $ 191 $ 24 $ 25 $ 11 $ 6 $ — $ — $ 141 Interest Rate Contracts Designated as Hedging Instruments Current $ 12 $ — $ — $ — $ — $ — $ — $ — Noncurrent 6 — — — — — — — Not Designated as Hedging Instruments Current 23 9 13 11 2 1 — — Noncurrent 10 — 6 5 1 4 — — Total Derivative Liabilities – Interest Rate Contracts $ 51 $ 9 $ 19 $ 16 $ 3 $ 5 $ — $ — Total Derivative Liabilities $ 242 $ 33 $ 44 $ 27 $ 9 $ 5 $ — $ 141 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 June 30, 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 $ 37 $ — $ — $ — $ — $ 7 $ 29 $ 2 Gross amounts offset — — — — — — — — Net amounts presented in Current Assets: Other $ 37 $ — $ — $ — $ — $ 7 $ 29 $ 2 Noncurrent Gross amounts recognized $ 1 $ — $ — $ — $ — $ — $ — $ — Gross amounts offset — — — — — — — — Net amounts presented in Other Noncurrent Assets: Other $ 1 $ — $ — $ — $ — $ — $ — $ — Derivative Liabilities June 30, 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 $ 154 $ 85 $ 55 $ 26 $ 29 $ 1 $ 2 $ 7 Gross amounts offset (1 ) — (1 ) (1 ) — — — — Net amounts presented in Current Liabilities: Other $ 153 $ 85 $ 54 $ 25 $ 29 $ 1 $ 2 $ 7 Noncurrent Gross amounts recognized $ 188 $ 8 $ 35 $ 9 $ 10 $ 5 $ — $ 107 Gross amounts offset — — — — — — — — Net amounts presented in Other Noncurrent Liabilities: Other $ 188 $ 8 $ 35 $ 9 $ 10 $ 5 $ — $ 107 Derivative Assets December 31, 2018 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 $ 38 $ 2 $ 2 $ 2 $ — $ 6 $ 23 $ 3 Gross amounts offset (3 ) (2 ) (2 ) (2 ) — — — — Net amounts presented in Current Assets: Other $ 35 $ — $ — $ — $ — $ 6 $ 23 $ 3 Noncurrent Gross amounts recognized $ 19 $ 1 $ 2 $ 2 $ — $ — $ — $ — Gross amounts offset (3 ) (1 ) (2 ) (2 ) — — — — Net amounts presented in Other Noncurrent Assets: Other $ 16 $ — $ — $ — $ — $ — $ — $ — Derivative Liabilities December 31, 2018 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 $ 68 $ 23 $ 23 $ 16 $ 8 $ 1 $ — $ 8 Gross amounts offset (4 ) (2 ) (2 ) (2 ) — — — — Net amounts presented in Current Liabilities: Other $ 64 $ 21 $ 21 $ 14 $ 8 $ 1 $ — $ 8 Noncurrent Gross amounts recognized $ 174 $ 10 $ 21 $ 11 $ 1 $ 4 $ — $ 133 Gross amounts offset (3 ) (1 ) (2 ) (2 ) — — — — Net amounts presented in Other Noncurrent Liabilities: Other $ 171 $ 9 $ 19 $ 9 $ 1 $ 4 $ — $ 133 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. June 30, 2019 Duke Duke Duke Energy Progress Energy (in millions) Energy Carolinas Energy Progress Aggregate fair value of derivatives in a net liability position $ 67 $ 34 $ 33 $ 33 Fair value of collateral already posted — — — — Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered 67 34 33 33 December 31, 2018 Duke Duke Duke Energy Progress Energy (in millions) Energy Carolinas Energy Progress Aggregate fair value of derivatives in a net liability position $ 44 $ 19 $ 25 $ 25 Fair value of collateral already posted — — — — Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered 44 19 25 25 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	6 Months Ended
	Jun. 30, 2019
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 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 considered OTTIs and 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 is other-than-temporarily impaired. The Duke Energy Registrants analyze all investment holdings each reporting period to determine whether a decline in fair value should be considered other-than-temporary. If an OTTI exists, the unrealized credit loss is included in earnings. There were no material credit losses as of June 30, 2019 , and December 31, 2018 . 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. June 30, 2019 December 31, 2018 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 $ — $ — $ 114 $ — $ — $ 88 Equity securities 3,076 36 5,178 2,402 95 4,475 Corporate debt securities 30 1 571 4 13 566 Municipal bonds 10 — 318 1 4 353 U.S. government bonds 34 1 1,270 14 12 1,076 Other debt securities 3 1 152 — 2 148 Total NDTF Investments $ 3,153 $ 39 $ 7,603 $ 2,421 $ 126 $ 6,706 Other Investments Cash and cash equivalents $ — $ — $ 49 $ — $ — $ 22 Equity securities 49 — 112 36 1 99 Corporate debt securities 2 — 60 — 2 60 Municipal bonds 3 1 90 — 1 85 U.S. government bonds 2 — 51 1 — 45 Other debt securities — — 65 — 1 58 Total Other Investments $ 56 $ 1 $ 427 $ 37 $ 5 $ 369 Total Investments $ 3,209 $ 40 $ 8,030 $ 2,458 $ 131 $ 7,075 Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three and six months ended June 30, 2019 , and 2018, were as follows. Three Months Ended Six Months Ended (in millions) June 30, 2019 June 30, 2018 June 30, 2019 June 30, 2018 FV-NI: Realized gains $ 66 $ 47 $ 101 $ 66 Realized losses 63 31 93 44 AFS: Realized gains 47 5 57 10 Realized losses 36 12 47 25 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. June 30, 2019 December 31, 2018 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 $ — $ — $ 41 $ — $ — $ 29 Equity securities 1,671 9 2,883 1,309 54 2,484 Corporate debt securities 18 1 360 2 9 341 Municipal bonds 2 — 63 — 1 81 U.S. government bonds 17 1 556 5 8 475 Other debt securities 3 1 141 — 2 143 Total NDTF Investments $ 1,711 $ 12 $ 4,044 $ 1,316 $ 74 $ 3,553 Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three and six months ended June 30, 2019 , and 2018, were as follows. Three Months Ended Six Months Ended (in millions) June 30, 2019 June 30, 2018 June 30, 2019 June 30, 2018 FV-NI: Realized gains $ 44 $ 26 $ 67 $ 36 Realized losses 48 17 69 22 AFS: Realized gains 16 4 25 9 Realized losses 11 8 21 18 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. June 30, 2019 December 31, 2018 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 $ — $ — $ 73 $ — $ — $ 59 Equity securities 1,405 27 2,295 1,093 41 1,991 Corporate debt securities 12 — 211 2 4 225 Municipal bonds 8 — 255 1 3 272 U.S. government bonds 17 — 714 9 4 601 Other debt securities — — 11 — — 5 Total NDTF Investments $ 1,442 $ 27 $ 3,559 $ 1,105 $ 52 $ 3,153 Other Investments Cash and cash equivalents $ — $ — $ 47 $ — $ — $ 17 Municipal bonds 3 — 50 — — 47 Total Other Investments $ 3 $ — $ 97 $ — $ — $ 64 Total Investments $ 1,445 $ 27 $ 3,656 $ 1,105 $ 52 $ 3,217 Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three and six months ended June 30, 2019 , and 2018, were as follows. Three Months Ended Six Months Ended (in millions) June 30, 2019 June 30, 2018 June 30, 2019 June 30, 2018 FV-NI: Realized gains $ 22 $ 21 $ 34 $ 30 Realized losses 15 14 24 22 AFS: Realized gains 30 1 31 1 Realized losses 25 4 26 7 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. June 30, 2019 December 31, 2018 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 $ — $ — $ 42 $ — $ — $ 46 Equity securities 1,092 24 1,886 833 30 1,588 Corporate debt securities 12 — 211 2 3 171 Municipal bonds 8 — 255 1 3 271 U.S. government bonds 16 — 429 6 3 415 Other debt securities — — 11 — — 3 Total NDTF Investments $ 1,128 $ 24 $ 2,834 $ 842 $ 39 $ 2,494 Other Investments Cash and cash equivalents $ — $ — $ 2 $ — $ — $ 6 Total Other Investments $ — $ — $ 2 $ — $ — $ 6 Total Investments $ 1,128 $ 24 $ 2,836 $ 842 $ 39 $ 2,500 Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three and six months ended June 30, 2019 , and 2018, were as follows. Three Months Ended Six Months Ended (in millions) June 30, 2019 June 30, 2018 June 30, 2019 June 30, 2018 FV-NI: Realized gains $ 7 $ 17 $ 17 $ 25 Realized losses 7 12 15 20 AFS: Realized gains 1 1 2 1 Realized losses 1 3 2 5 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. June 30, 2019 December 31, 2018 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 $ — $ — $ 31 $ — $ — $ 13 Equity securities 313 3 409 260 11 403 Corporate debt securities — — — — 1 54 Municipal bonds — — — — — 1 U.S. government bonds 1 — 285 3 1 186 Other debt securities — — — — — 2 Total NDTF Investments (a) $ 314 $ 3 $ 725 $ 263 $ 13 $ 659 Other Investments Cash and cash equivalents $ — $ — $ 2 $ — $ — $ 1 Municipal bonds 3 — 50 — — 47 Total Other Investments $ 3 $ — $ 52 $ — $ — $ 48 Total Investments $ 317 $ 3 $ 777 $ 263 $ 13 $ 707 (a) During the six months ended June 30, 2019 , 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 and six months ended June 30, 2019 , and 2018, were as follows. Three Months Ended Six Months Ended (in millions) June 30, 2019 June 30, 2018 June 30, 2019 June 30, 2018 FV-NI: Realized gains $ 15 $ 4 $ 17 $ 5 Realized losses 8 2 9 2 AFS: Realized gains 29 — 29 — Realized losses 24 1 24 2 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. June 30, 2019 December 31, 2018 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 $ 37 $ — $ 74 $ 29 $ — $ 67 Corporate debt securities — — 7 — — 8 Municipal bonds — 1 34 — 1 33 U.S. government bonds — — 1 — — — Total Investments $ 37 $ 1 $ 116 $ 29 $ 1 $ 108 Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three and six months ended June 30, 2019 , and 2018, were insignificant. DEBT SECURITY MATURITIES The table below summarizes the maturity date for debt securities. June 30, 2019 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Indiana Due in one year or less $ 365 $ 43 $ 315 $ 29 $ 286 $ 4 Due after one through five years 527 213 265 257 8 15 Due after five through 10 years 499 242 203 192 11 4 Due after 10 years 1,186 622 458 428 30 19 Total $ 2,577 $ 1,120 $ 1,241 $ 906 $ 335 $ 42

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2019
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 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. Transfers between levels represent assets or liabilities that were previously (i) categorized at a higher level for which the inputs to the estimate became less observable or (ii) classified at a lower level for which the inputs became more observable during the period. The Duke Energy Registrant’s policy is to recognize transfers between levels of the fair value hierarchy at the end of the period. There were no transfers between levels during the six months ended June 30, 2019 , and 2018 . 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. Other commodity derivatives, including Piedmont's natural gas supply contracts, are primarily valued using internally developed discounted cash flow models that incorporate forward price, adjustments for liquidity (bid-ask spread) and credit or non-performance risk (after reflecting credit enhancements such as collateral), and are discounted to present value. Pricing inputs are derived from published exchange transaction prices and other observable data sources. In the absence of an active market, the last available price may be used. If forward price curves are not observable for the full term of the contract and the unobservable period had more than an insignificant impact on the valuation, the commodity derivative is classified as Level 3. In isolation, increases (decreases) in natural gas forward prices result in favorable (unfavorable) fair value adjustments for natural gas purchase contracts; and increases (decreases) in electricity forward prices result in unfavorable (favorable) fair value adjustments for electricity sales contracts. Duke Energy regularly evaluates and validates pricing inputs used to estimate the fair value of natural gas commodity contracts by a market participant price verification procedure. This procedure provides a comparison of internal forward commodity curves to market participant generated curves. Interest rate derivatives Most over-the-counter interest rate contract derivatives are valued using financial models that utilize observable inputs for similar instruments and are classified as Level 2. Inputs include forward interest rate curves, notional amounts, interest rates and credit quality of the counterparties. Other fair value considerations See Note 11 in Duke Energy's Annual Report on Form 10-K for the year ended December 31, 2018, 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 10 . See Note 11 for additional information related to investments by major security type for the Duke Energy Registrants. June 30, 2019 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not Categorized NDTF equity securities $ 5,178 $ 5,119 $ — $ — $ 59 NDTF debt securities 2,425 870 1,555 — — Other equity securities 112 112 — — — Other debt securities 315 99 216 — — Derivative assets 38 3 — 35 — Total assets 8,068 6,203 1,771 35 59 Derivative liabilities (342 ) (12 ) (216 ) (114 ) — Net assets (liabilities) $ 7,726 $ 6,191 $ 1,555 $ (79 ) $ 59 December 31, 2018 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not Categorized NDTF equity securities $ 4,475 $ 4,410 $ — $ — $ 65 NDTF debt securities 2,231 576 1,655 — — Other equity securities 99 99 — — — Other debt securities 270 67 203 — — Derivative assets 57 4 25 28 — Total assets 7,132 5,156 1,883 28 65 Derivative liabilities (242 ) (11 ) (90 ) (141 ) — Net assets (liabilities) $ 6,890 $ 5,145 $ 1,793 $ (113 ) $ 65 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 June 30, Six Months Ended June 30, (in millions) 2019 2018 2019 2018 Balance at beginning of period $ (115 ) $ (124 ) $ (113 ) $ (114 ) Purchases, sales, issuances and settlements: Purchases 38 56 38 56 Settlements (11 ) (15 ) (23 ) (29 ) Total gains (losses) included on the Condensed Consolidated Balance Sheet 9 (14 ) 19 (10 ) Balance at end of period $ (79 ) $ (97 ) $ (79 ) $ (97 ) 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. June 30, 2019 (in millions) Total Fair Value Level 1 Level 2 Not Categorized NDTF equity securities $ 2,883 $ 2,824 $ — $ 59 NDTF debt securities 1,161 250 911 — Total assets 4,044 3,074 911 59 Derivative liabilities (93 ) — (93 ) — Net assets $ 3,951 $ 3,074 $ 818 $ 59 December 31, 2018 (in millions) Total Fair Value Level 1 Level 2 Not Categorized NDTF equity securities $ 2,484 $ 2,419 $ — $ 65 NDTF debt securities 1,069 149 920 — Derivative assets 3 — 3 — Total assets 3,556 2,568 923 65 Derivative liabilities (33 ) — (33 ) — Net assets $ 3,523 $ 2,568 $ 890 $ 65 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. June 30, 2019 December 31, 2018 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 NDTF equity securities $ 2,295 $ 2,295 $ — $ 1,991 $ 1,991 $ — NDTF debt securities 1,264 620 644 1,162 427 735 Other debt securities 97 47 50 64 17 47 Derivative assets — — — 4 — 4 Total assets 3,656 2,962 694 3,221 2,435 786 Derivative liabilities (90 ) — (90 ) (44 ) — (44 ) Net assets $ 3,566 $ 2,962 $ 604 $ 3,177 $ 2,435 $ 742 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. June 30, 2019 December 31, 2018 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 NDTF equity securities $ 1,886 $ 1,886 $ — $ 1,588 $ 1,588 $ — NDTF debt securities 948 304 644 906 294 612 Other debt securities 2 2 — 6 6 — Derivative assets — — — 4 — 4 Total assets 2,836 2,192 644 2,504 1,888 616 Derivative liabilities (35 ) — (35 ) (27 ) — (27 ) Net assets $ 2,801 $ 2,192 $ 609 $ 2,477 $ 1,888 $ 589 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. June 30, 2019 December 31, 2018 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 NDTF equity securities $ 409 $ 409 $ — $ 403 $ 403 $ — NDTF debt securities 316 316 — 256 133 123 Other debt securities 52 2 50 48 1 47 Total assets 777 727 50 707 537 170 Derivative liabilities (39 ) — (39 ) (9 ) — (9 ) Net assets $ 738 $ 727 $ 11 $ 698 $ 537 $ 161 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 June 30, 2019 , and December 31, 2018 . 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. June 30, 2019 December 31, 2018 (in millions) Total Fair Value Level 1 Level 2 Level 3 Total Fair Value Level 1 Level 2 Level 3 Other equity securities $ 74 $ 74 $ — $ — $ 67 $ 67 $ — $ — Other debt securities 42 — 42 — 41 — 41 — Derivative assets 29 1 — 28 23 1 — 22 Total assets $ 145 $ 75 $ 42 $ 28 $ 131 $ 68 $ 41 $ 22 Derivative liabilities (2 ) (2 ) — — — — — — Net assets $ 143 $ 73 $ 42 $ 28 $ 131 $ 68 $ 41 $ 22 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 June 30, Six Months Ended June 30, (in millions) 2019 2018 2019 2018 Balance at beginning of period $ 5 $ 7 $ 22 $ 27 Purchases, sales, issuances and settlements: Purchases 29 49 29 49 Settlements (9 ) (14 ) (19 ) (28 ) Total gains (losses) included on the Condensed Consolidated Balance Sheet 3 2 (4 ) (4 ) Balance at end of period $ 28 $ 44 $ 28 $ 44 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. June 30, 2019 December 31, 2018 (in millions) Total Fair Value Level 1 Level 3 Total Fair Value Level 1 Level 3 Derivative assets $ 2 $ 2 $ — $ 3 3 — Derivative liabilities (114 ) — (114 ) (141 ) — (141 ) Net (liabilities) assets $ (112 ) $ 2 $ (114 ) $ (138 ) $ 3 $ (141 ) 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 June 30, Six Months Ended June 30, (in millions) 2019 2018 2019 2018 Balance at beginning of period $ (121 ) $ (132 ) $ (141 ) $ (142 ) Total gains (losses) and settlements 7 (18 ) 27 (8 ) Balance at end of period $ (114 ) $ (150 ) $ (114 ) $ (150 ) QUANTITATIVE INFORMATION ABOUT UNOBSERVABLE INPUTS The following tables include quantitative information about the Duke Energy Registrants' derivatives classified as Level 3. June 30, 2019 Fair Value Investment Type (in millions) Valuation Technique Unobservable Input Range Duke Energy Ohio FTRs $ 7 RTO auction pricing FTR price – per MWh $ 0.36 - $ 3.13 Duke Energy Indiana FTRs 28 RTO auction pricing FTR price – per MWh (0.59 ) - 7.61 Piedmont Natural gas contracts (114 ) Discounted cash flow Forward natural gas curves – price per MMBtu 1.96 - 3.21 Duke Energy Total Level 3 derivatives $ (79 ) December 31, 2018 Fair Value Investment Type (in millions) Valuation Technique Unobservable Input Range Duke Energy Ohio FTRs $ 6 RTO auction pricing FTR price – per MWh $ 1.19 - $ 4.59 Duke Energy Indiana FTRs 22 RTO auction pricing FTR price – per MWh (2.07 ) - 8.27 Piedmont Natural gas contracts (141 ) Discounted cash flow Forward natural gas curves – price per MMBtu 1.87 - 2.95 Duke Energy Total Level 3 derivatives $ (113 ) 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. June 30, 2019 December 31, 2018 (in millions) Book Value Fair Value Book Value Fair Value Duke Energy (a) $ 57,040 $ 60,667 $ 54,529 $ 54,534 Duke Energy Carolinas 10,964 12,300 10,939 11,471 Progress Energy 19,199 21,408 18,911 19,885 Duke Energy Progress 9,049 9,707 8,204 8,300 Duke Energy Florida 7,213 8,173 7,321 7,742 Duke Energy Ohio 2,509 2,779 2,165 2,239 Duke Energy Indiana 3,723 4,363 3,782 4,158 Piedmont 2,384 2,576 2,138 2,180 (a) Book value of long-term debt includes $1.5 billion as of June 30, 2019 , and $1.6 billion as of December 31, 2018 , of unamortized debt discount and premium, net in purchase accounting adjustments related to the mergers with Progress Energy and Piedmont that are excluded from fair value of long-term debt. At both June 30, 2019 , and December 31, 2018 , 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	6 Months Ended
	Jun. 30, 2019
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 six months ended June 30, 2019 , and the year ended December 31, 2018 , 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 limited liability companies 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 primary beneficiaries and consolidate DERF, DEPR and DEFR, respectively, as they make those decisions. Receivables Financing – CRC CRC is a bankruptcy remote, special purpose entity indirectly owned by Duke Energy. On a revolving basis, CRC buys certain accounts receivable arising from the sale of electricity, natural gas and related services from Duke Energy Ohio and Duke Energy Indiana. CRC borrows amounts under a credit facility to buy the receivables from Duke Energy Ohio and Duke Energy Indiana. Borrowing availability from the credit facility is limited to the amount of qualified receivables sold to CRC. 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 percent cash and 25 percent 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 are not performed by the equity holder and (iii) deficiencies in net worth of CRC are funded by Duke Energy. The most significant activities that impact the economic performance of CRC are decisions made to manage delinquent receivables. Duke Energy is considered the primary beneficiary and consolidates CRC as it makes these decisions. Neither Duke Energy Ohio nor Duke Energy Indiana consolidate CRC. Receivables Financing – Credit Facilities The following table summarizes the amounts and expiration dates of the credit facilities and associated restricted receivables described above. Duke Energy Duke Energy Duke Energy Duke Energy Carolinas Progress Florida (in millions) CRC DERF DEPR DEFR Expiration date December 2020 December 2020 February 2021 April 2021 Credit facility amount $ 350 $ 475 $ 325 $ 250 Amounts borrowed at June 30, 2019 328 475 325 250 Amounts borrowed at December 31, 2018 325 450 300 225 Restricted Receivables at June 30, 2019 484 671 518 472 Restricted Receivables at December 31, 2018 564 699 547 357 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 June 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) June 30, 2019 December 31, 2018 Receivables of VIEs $ 8 $ 5 Regulatory Assets: Current 52 52 Current Assets: Other 31 39 Other Noncurrent Assets: Regulatory assets 1,019 1,041 Current Liabilities: Other 10 10 Current maturities of long-term debt 54 53 Long-Term Debt 1,082 1,111 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 solar energy systems 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 EPC 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 renewables VIEs. (in millions) June 30, 2019 December 31, 2018 Current Assets: Other $ 109 $ 123 Property, plant and equipment, cost 4,419 4,007 Accumulated depreciation and amortization (769 ) (698 ) Other Noncurrent Assets: Other 289 261 Current maturities of long-term debt 178 174 Long-Term Debt 1,610 1,587 Other Noncurrent Liabilities: Asset Retirement Obligations 108 106 Other Noncurrent Liabilities: Other 222 212 NON-CONSOLIDATED VIEs The following tables summarize the impact of non-consolidated VIEs on the Condensed Consolidated Balance Sheets. June 30, 2019 Duke Energy Duke Duke Pipeline Commercial Other Energy Energy (in millions) Investments Renewables VIEs Total Ohio Indiana Receivables from affiliated companies $ — $ — $ — $ — $ 45 $ 81 Investments in equity method unconsolidated affiliates 1,066 187 52 1,305 — — Total assets $ 1,066 $ 187 $ 52 $ 1,305 $ 45 $ 81 Taxes accrued (2 ) — — (2 ) — — Other current liabilities — — 4 4 — — Deferred income taxes 48 — — 48 — — Other noncurrent liabilities — — 11 11 — — Total liabilities $ 46 $ — $ 15 $ 61 $ — $ — Net assets $ 1,020 $ 187 $ 37 $ 1,244 $ 45 $ 81 December 31, 2018 Duke Energy Duke Duke Pipeline Commercial Other Energy Energy (in millions) Investments Renewables VIEs Total Ohio Indiana Receivables from affiliated companies $ — $ — $ — $ — $ 93 $ 118 Investments in equity method unconsolidated affiliates 822 190 48 1,060 — — Total assets $ 822 $ 190 $ 48 $ 1,060 $ 93 $ 118 Taxes accrued (1 ) — — (1 ) — — Other current liabilities — — 4 4 — — Deferred income taxes 21 — — 21 — — Other noncurrent liabilities — — 12 12 — — Total liabilities $ 20 $ — $ 16 $ 36 $ — $ — Net assets $ 802 $ 190 $ 32 $ 1,024 $ 93 $ 118 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 power purchase agreement 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 $790 million , which represents 47 percent of the outstanding borrowings under the credit facility as of June 30, 2019 . 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 June 30, December 31, Entity Name Interest 2019 2018 ACP (a) 47 % $ 1,041 $ 797 Constitution 24 % 25 25 Total $ 1,066 $ 822 (a) Duke Energy evaluated this investment for impairment as of June 30, 2019 , and December 31, 2018 , and determined that fair value approximated carrying value and therefore no impairment was necessary. 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. Pioneer Duke Energy holds a 50 percent equity interest in Pioneer. Pioneer is considered a VIE due to having insufficient equity to finance its own activities without subordinated financial support. The activities that most significantly impact Pioneer's economic performance are decisions related to the development of new transmission facilities. The power to direct these activities is jointly and equally shared by Duke Energy and the other joint venture partner, American Electric Power; therefore, Duke Energy does not consolidate Pioneer. OVEC Duke Energy Ohio’s 9 percent 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 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, FES, a subsidiary of FirstEnergy and an ICPA counterparty with a power participation ratio of 4.85 percent, 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. Duke Energy Ohio cannot predict the impact of the bankruptcy filing on its OVEC interests. In addition, certain proposed environmental rulemaking could result in future increased OVEC cost allocations. 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) June 30, 2019 December 31, 2018 June 30, 2019 December 31, 2018 Receivables sold $ 210 $ 269 $ 314 $ 336 Less: Retained interests 45 93 81 118 Net receivables sold $ 165 $ 176 $ 233 $ 218 The following table shows sales and cash flows related to receivables sold. Duke Energy Ohio Duke Energy Indiana Three Months Ended Six Months Ended Three Months Ended Six Months Ended June 30, June 30, June 30, June 30, (in millions) 2019 2018 2019 2018 2019 2018 2019 2018 Sales Receivables sold $ 429 $ 461 $ 1,004 $ 1,028 $ 676 $ 692 $ 1,410 $ 1,386 Loss recognized on sale 3 3 7 6 4 4 9 7 Cash flows Cash proceeds from receivables sold $ 448 $ 465 $ 1,045 $ 1,050 $ 680 $ 686 $ 1,438 $ 1,397 Collection fees received 1 1 1 1 1 1 1 1 Return received on retained interests 2 1 4 3 2 2 5 4 Cash flows from sales of receivables are reflected within Operating Activities on Duke Energy Ohio’s and Duke Energy Indiana’s Condensed Consolidated Statements of Cash Flows.

Revenue

Revenue	6 Months Ended
	Jun. 30, 2019
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) 2019 2020 2021 2022 2023 Thereafter Total Progress Energy $ 63 $ 121 $ 87 $ 82 $ 39 $ 42 $ 434 Duke Energy Progress 4 9 9 9 9 9 49 Duke Energy Florida 59 112 78 73 30 33 385 Duke Energy Indiana 5 10 5 — — — 20 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) 2019 2020 2021 2022 2023 Thereafter Total Piedmont $ 34 $ 69 $ 65 $ 64 $ 61 $ 432 $ 725 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 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 June 30, 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 $ 2,304 $ 679 $ 1,243 $ 496 $ 747 $ 159 $ 225 $ — General 1,584 531 750 339 411 105 197 — Industrial 759 289 231 164 67 36 201 — Wholesale 527 109 351 309 42 9 59 — Other revenues 187 68 99 44 55 25 27 — Total Electric Utilities and Infrastructure revenue from contracts with customers $ 5,361 $ 1,676 $ 2,674 $ 1,352 $ 1,322 $ 334 $ 709 $ — Gas Utilities and Infrastructure Residential $ 146 $ — $ — $ — $ — $ 64 $ — $ 82 Commercial 85 — — — — 26 — 59 Industrial 29 — — — — 3 — 24 Power Generation — — — — — — — 13 Other revenues 22 — — — — 2 — 19 Total Gas Utilities and Infrastructure revenue from contracts with customers $ 282 $ — $ — $ — $ — $ 95 $ — $ 197 Commercial Renewables Revenue from contracts with customers $ 46 $ — $ — $ — $ — $ — $ — $ — Other Revenue from contracts with customers $ 6 $ — $ — $ — $ — $ — $ — $ — Total revenue from contracts with customers $ 5,695 $ 1,676 $ 2,674 $ 1,352 $ 1,322 $ 429 $ 709 $ 197 Other revenue sources (a) $ 178 $ 37 $ 70 $ 35 $ 31 $ 4 $ 5 $ 12 Total revenues $ 5,873 $ 1,713 $ 2,744 $ 1,387 $ 1,353 $ 433 $ 714 $ 209 Three Months Ended June 30, 2018 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 $ 2,185 $ 659 $ 1,099 $ 452 $ 648 $ 181 $ 245 $ — General 1,481 501 678 300 377 110 188 — Industrial 736 286 224 159 66 33 192 — Wholesale 515 115 322 287 34 2 77 — Other revenues 194 85 96 47 50 23 20 — Total Electric Utilities and Infrastructure revenue from contracts with customers $ 5,111 $ 1,646 $ 2,419 $ 1,245 $ 1,175 $ 349 $ 722 $ — Gas Utilities and Infrastructure Residential $ 153 $ — $ — $ — $ — $ 66 $ — $ 87 Commercial 87 — — — — 28 — 59 Industrial 31 — — — — 3 — 28 Power Generation — — — — — — — 14 Other revenues 23 — — — — 6 — 17 Total Gas Utilities and Infrastructure revenue from contracts with customers $ 294 $ — $ — $ — $ — $ 103 $ — $ 205 Commercial Renewables Revenue from contracts with customers $ 47 $ — $ — $ — $ — $ — $ — $ — Other Revenue from contracts with customers $ 15 $ — $ — $ — $ — $ 10 $ — $ — Total revenue from contracts with customers $ 5,467 $ 1,646 $ 2,419 $ 1,245 $ 1,175 $ 462 $ 722 $ 205 Other revenue sources (a) $ 176 $ 26 $ 79 $ 46 $ 28 $ (3 ) $ 16 $ 10 Total revenues $ 5,643 $ 1,672 $ 2,498 $ 1,291 $ 1,203 $ 459 $ 738 $ 215 (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. Six Months Ended June 30, 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 $ 4,674 $ 1,439 $ 2,357 $ 1,032 $ 1,325 $ 348 $ 531 $ — General 3,011 1,027 1,382 645 737 208 394 — Industrial 1,470 555 453 325 128 69 391 — Wholesale 1,068 228 704 624 80 23 113 — Other revenues 359 146 271 169 102 41 44 — Total Electric Utilities and Infrastructure revenue from contracts with customers $ 10,582 $ 3,395 $ 5,167 $ 2,795 $ 2,372 $ 689 $ 1,473 $ — Gas Utilities and Infrastructure Residential $ 560 $ — $ — $ — $ — $ 176 $ — $ 384 Commercial 291 — — — — 75 — 216 Industrial 77 — — — — 10 — 66 Power Generation — — — — — — — 26 Other revenues 85 — — — — 10 — 75 Total Gas Utilities and Infrastructure revenue from contracts with customers $ 1,013 $ — $ — $ — $ — $ 271 $ — $ 767 Commercial Renewables Revenue from contracts with customers $ 88 $ — $ — $ — $ — $ — $ — $ — Other Revenue from contracts with customers $ 10 $ — $ — $ — $ — $ — $ — $ — Total Revenue from contracts with customers $ 11,693 $ 3,395 $ 5,167 $ 2,795 $ 2,372 $ 960 $ 1,473 $ 767 Other revenue sources (a) $ 343 $ 62 $ 149 $ 76 $ 67 $ 4 $ 9 $ 21 Total revenues $ 12,036 $ 3,457 $ 5,316 $ 2,871 $ 2,439 $ 964 $ 1,482 $ 788 Six Months Ended June 30, 2018 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 $ 4,535 $ 1,440 $ 2,211 $ 968 $ 1,243 $ 361 $ 523 $ — General 2,856 973 1,309 599 710 206 366 — Industrial 1,400 541 432 304 128 63 365 — Wholesale 1,148 234 768 684 84 2 145 — Other revenues 333 152 225 132 93 37 37 — Total Electric Utilities and Infrastructure revenue from contracts with customers $ 10,272 $ 3,340 $ 4,945 $ 2,687 $ 2,258 $ 669 $ 1,436 $ — Gas Utilities and Infrastructure Residential $ 566 $ — $ — $ — $ — $ 177 $ — $ 389 Commercial 288 — — — — 77 — 211 Industrial 79 — — — — 10 — 69 Power Generation — — — — — — — 27 Other revenues 78 — — — — 12 — 66 Total Gas Utilities and Infrastructure revenue from contracts with customers $ 1,011 $ — $ — $ — $ — $ 276 $ — $ 762 Commercial Renewables Revenue from contracts with customers $ 80 $ — $ — $ — $ — $ — $ — $ — Other Revenue from contracts with customers $ 31 $ — $ — $ — $ — $ 24 $ — $ — Total Revenue from contracts with customers $ 11,394 $ 3,340 $ 4,945 $ 2,687 $ 2,258 $ 969 $ 1,436 $ 762 Other revenue sources (a) $ 384 $ 95 $ 129 $ 64 $ 60 $ 14 $ 33 $ 6 Total revenues $ 11,778 $ 3,435 $ 5,074 $ 2,751 $ 2,318 $ 983 $ 1,469 $ 768 (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. 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) June 30, 2019 December 31, 2018 Duke Energy $ 790 $ 896 Duke Energy Carolinas 288 313 Progress Energy 270 244 Duke Energy Progress 148 148 Duke Energy Florida 122 96 Duke Energy Ohio 1 2 Duke Energy Indiana 14 23 Piedmont 4 73 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 13 for further information. These receivables for unbilled revenues are shown in the table below. (in millions) June 30, 2019 December 31, 2018 Duke Energy Ohio $ 65 $ 86 Duke Energy Indiana 116 128

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2019
Equity [Abstract]
Stockholders' Equity	STOCKHOLDERS' EQUITY Basic EPS is computed by dividing net income attributable 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 attributable 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. 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 June 30, Six Months Ended June 30, (in millions, except per-share amounts) 2019 2018 2019 2018 Income from continuing operations attributable to Duke Energy common stockholders excluding impact of participating securities $ 819 $ 504 $ 1,718 $ 1,123 Weighted average common shares outstanding – basic 728 703 728 702 Equity Forwards — 1 — — Weighted average common shares outstanding – diluted 728 704 728 702 EPS from continuing operations attributable to Duke Energy common stockholders Basic and Diluted $ 1.12 $ 0.72 $ 2.36 $ 1.60 Potentially dilutive items excluded from the calculation (a) 2 2 2 2 Dividends declared per common share $ 0.928 $ 0.89 $ 1.855 $ 1.78 Dividends declared on preferred stock per depositary share $ 0.307 $ — $ 0.307 $ — (a) Performance stock awards were not included in the dilutive securities calculation because the performance measures related to the awards had not been met. Common Stock On February 20, 2018, Duke Energy filed a prospectus supplement and executed an EDA under which it may sell up to $1 billion of its common stock through an ATM offering program, including an equity forward sales component. The EDA was entered into with the Agents. Under the terms of the EDA, Duke Energy may issue and sell, through any of the Agents, shares of common stock through September 23, 2019. In June 2018, Duke Energy marketed two separate tranches, each for 1.3 million shares, of common stock through equity forward transactions under the ATM program. In December 2018, Duke Energy physically settled these equity forwards by delivering 2.6 million shares of common stock in exchange for net proceeds of approximately $195 million . Separately, in March 2018, Duke Energy marketed an equity offering of 21.3 million shares of common stock through an Underwriting Agreement. In connection with the offering, Duke Energy entered into equity forward sale agreements. The equity forwards required Duke Energy to either physically settle the transactions by issuing 21.3 million shares in exchange for net proceeds at the then-applicable forward sale price specified by the agreements, or net settle in whole or in part through the delivery or receipt of cash or shares. In June 2018, Duke Energy physically settled one-half of the equity forwards by delivering approximately 10.6 million shares of common stock in exchange for net cash proceeds of approximately $781 million . In December 2018, Duke Energy physically settled the remaining equity forward by delivering 10.6 million shares of common stock in exchange for net cash proceeds of approximately $766 million . In 2018, Duke Energy also issued 2.2 million shares through its DRIP with an increase in additional paid-in capital of approximately $174 million . For the six months ended June 30, 2019 , Duke Energy issued 0.9 million shares through its DRIP with an increase in additional paid-in capital of approximately $80 million . In March and April 2019, Duke Energy marketed two separate tranches, each for 1.1 million shares, of common stock through equity forward transactions under the ATM program. The first tranche had an initial forward price of $89.83 per share and the second tranche had an initial forward price of $88.82 per share. In May and June 2019, a third tranche of 1.6 million shares of common stock was marketed and had an initial forward price of $86.23 . The equity forwards 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 agreements or net settle in whole or in part through the delivery or receipt of cash or shares. The settlement alternative is at Duke Energy's election. No amounts have or will be recorded in Duke Energy's Condensed Consolidated Financial Statements with respect to these ATM offerings until settlements of the equity forwards occur, which is expected by December 31, 2019. The initial forward sale price will be subject to adjustment based on a floating interest rate factor and other fixed amounts specified in the relevant forward sale agreements. Until settlement of the equity forwards, EPS dilution resulting from the agreements, if any, will be determined under the treasury stock method. Preferred Stock On March 29, 2019, Duke Energy completed the issuance of 40 million depositary shares, each representing 1/1,000th share of its Series A Cumulative Redeemable Perpetual Preferred Stock, at a price of $25 per depositary share. The transaction resulted in net proceeds of $973 million after issuance costs and the proceeds are being used for general corporate purposes and to reduce short-term debt. The preferred stock has a $25 liquidation preference per depositary share and earns dividends on a cumulative basis at a rate of 5.75 percent per annum. Dividends are payable quarterly in arrears on the 16th day of March, June, September and December, and began on June 16, 2019. Dividends issued on its preferred stock are subject to approval by the Duke Energy Board of Directors. However, the deferral of dividend payments on the preferred stock prohibits the declaration of common stock dividends. Dividends declared on preferred stock will be recorded on the income statement as a reduction of net income to arrive at net income attributable to Duke Energy common stockholders. Dividends accumulated on preferred stock will be a reduction to net income used in the calculation of basic and diluted EPS. The Series A Preferred Stock ranks, with respect to dividends and distributions upon liquidation or dissolution: • senior to Common Stock and to each other class or series of capital stock established after the original issue date of the Series A Preferred Stock that is expressly made subordinated to the Series A Preferred Stock; • on a parity with any class or series of capital stock established after the original issue date of the Series A Preferred Stock that is not expressly made senior or subordinated to the Series A Preferred Stock; • junior to any class or series of capital stock established after the original issue date of the Series A Preferred Stock that is expressly made senior to the Series A Preferred Stock; • junior to all of existing and future indebtedness (including indebtedness outstanding under Duke Energy's credit facilities, unsecured senior notes, junior subordinated debentures and commercial paper) and other liabilities with respect to assets available to satisfy claims against Duke Energy; and • structurally subordinated to existing and future indebtedness and other liabilities of Duke Energy's subsidiaries and future preferred stock of subsidiaries. The preferred stock has no maturity or mandatory redemption date, is not redeemable at the option of the holders and includes separate call options. The first call option allows Duke Energy to call the preferred stock at a redemption price of $25.50 per depositary share prior to June 15, 2024, in whole but not in part, at any time within 120 days after a ratings event where a rating agency amends, clarifies or changes the criteria it uses to assign equity credit for securities such as the preferred stock. The second call option allows Duke Energy to call the preferred stock, in whole or in part, at any time, on or after June 15, 2024, at a redemption price of $25 per depositary share. Duke Energy is also required to redeem all accumulated and unpaid dividends if either call option is exercised. Holders of the preferred stock have no voting rights with respect to matters that generally require the approval of voting stockholders. The limited voting rights of holders of preferred stock include the right to vote as a single class on certain matters that may affect the preference or special rights of the preferred stock, except in the instance that Duke Energy elects to defer the payment of dividends for a total of six quarterly full dividend periods. If dividends are deferred for a cumulative total of six quarterly full dividend periods, whether or not for consecutive dividend periods, holders of the preferred stock have the right to elect two additional Board members to the Duke Energy Board of Directors.

Employee Benefit Plans

Employee Benefit Plans	6 Months Ended
	Jun. 30, 2019
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. Duke Energy uses a December 31 measurement date for its qualified non-contributory defined benefit retirement plan assets and obligations. However, because Duke Energy believes it is probable in 2019 that total lump-sum benefit payments will exceed the settlement threshold, which is defined as the sum of the service cost and interest cost on projected benefit obligation components of net periodic pension costs, Duke Energy remeasured the plan assets and plan obligations associated with one of its qualified pension plans as of June 30, 2019. The discount rate used for the remeasurement was 3.5 percent . The cash balance interest crediting rate was 4.0 percent . All other assumptions used for the remeasurement were consistent with the measurement as of December 31, 2018. As a result, Duke Energy recognized a remeasurement gain of $18 million , which is recorded in Other within Other Noncurrent Assets on the Condensed Consolidated Balance Sheets as of June 30, 2019. The remeasurement gain, which represents an increase in funded status, reflects an increase of $275 million in the fair value of plan assets and an increase of $257 million in the projected benefit obligation. As the result of settlement accounting, Duke Energy recognized a settlement charge of $69 million , primarily as a regulatory asset within Other Noncurrent Assets on the Condensed Consolidated Balance Sheets as of June 30, 2019 (an immaterial amount was recorded in Other income and expenses, net within the Condensed Consolidated Statement of Operations). Settlement charges recognized by the Subsidiary Registrants were $43 million for Duke Energy Carolinas, $16 million for Duke Energy Progress, $3 million for Duke Energy Florida, $3 million for Duke Energy Indiana, $1 million for Duke Energy Ohio and $3 million for Piedmont. The settlement charge reflects the recognition of a pro - rata portion of previously unrecognized actuarial losses, equal to the percentage of reduction in the projected benefit obligation resulting from total lump-sum benefits payments as of June 30, 2019. QUALIFIED PENSION PLANS The following tables include the components of net periodic pension costs for qualified pension plans. Three Months Ended June 30, 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 $ 10 $ 6 $ 6 $ 1 $ 2 $ 2 Interest cost on projected benefit obligation 82 21 26 12 13 4 7 3 Expected return on plan assets (143 ) (37 ) (45 ) (21 ) (22 ) (6 ) (10 ) (6 ) Amortization of actuarial loss 25 5 9 3 6 — 1 1 Amortization of prior service credit (8 ) (2 ) — (1 ) (1 ) — (1 ) (2 ) Net periodic pension costs $ (7 ) $ (1 ) $ — $ (1 ) $ 2 $ (1 ) $ (1 ) $ (2 ) Three Months Ended June 30, 2018 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Service cost $ 45 $ 15 $ 13 $ 8 $ 6 $ 1 $ 3 $ 2 Interest cost on projected benefit obligation 75 18 22 10 12 4 6 3 Expected return on plan assets (140 ) (37 ) (43 ) (21 ) (23 ) (7 ) (11 ) (6 ) Amortization of actuarial loss 33 7 11 5 6 1 2 3 Amortization of prior service credit (8 ) (2 ) (1 ) (1 ) (1 ) — — (3 ) Net periodic pension costs $ 5 $ 1 $ 2 $ 1 $ — $ (1 ) $ — $ (1 ) Six Months Ended June 30, 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 $ 74 $ 24 $ 21 $ 12 $ 10 $ 2 $ 4 $ 3 Interest cost on projected benefit obligation 165 41 52 24 27 9 13 6 Expected return on plan assets (286 ) (75 ) (89 ) (44 ) (44 ) (14 ) (21 ) (11 ) Amortization of actuarial loss 49 11 18 6 12 1 3 3 Amortization of prior service credit (16 ) (4 ) (1 ) (1 ) (1 ) — (1 ) (5 ) Net periodic pension costs $ (14 ) $ (3 ) $ 1 $ (3 ) $ 4 $ (2 ) $ (2 ) $ (4 ) Six Months Ended June 30, 2018 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Service cost $ 90 $ 30 $ 26 $ 15 $ 11 $ 2 $ 5 $ 4 Interest cost on projected benefit obligation 150 36 46 21 25 9 12 6 Expected return on plan assets (280 ) (74 ) (88 ) (42 ) (46 ) (14 ) (21 ) (12 ) Amortization of actuarial loss 66 14 22 10 12 2 4 6 Amortization of prior service credit (16 ) (4 ) (2 ) (1 ) (1 ) — — (6 ) Net periodic pension costs $ 10 $ 2 $ 4 $ 3 $ 1 $ (1 ) $ — $ (2 ) NON-QUALIFIED PENSION PLANS Net periodic pension costs for non-qualified pension plans were not material for the three and six months ended June 30, 2019, and 2018. OTHER POST-RETIREMENT BENEFIT PLANS Net periodic costs for OPEB plans were not material for the three and six months ended June 30, 2019, and 2018.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2019
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 Six Months Ended June 30, June 30, 2019 2018 2019 2018 Duke Energy 15.9 % 16.5 % 12.6 % 19.9 % Duke Energy Carolinas 19.7 % 21.5 % 18.7 % 21.8 % Progress Energy 16.7 % 17.3 % 17.0 % 15.4 % Duke Energy Progress 16.3 % 20.1 % 17.1 % 16.8 % Duke Energy Florida 19.6 % 18.0 % 19.5 % 17.4 % Duke Energy Ohio 16.1 % 25.8 % 16.5 % 16.0 % Duke Energy Indiana 24.2 % 25.8 % 24.2 % 25.8 % Piedmont 22.2 % 27.3 % 21.8 % 23.9 % The decrease in the ETR for Duke Energy for the six months ended June 30, 2019, is primarily due to a one-time valuation allowance charge in the prior year, an adjustment related to the income tax recognition for equity method investments recorded in the first quarter of 2019 and 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 and six months ended June 30, 2019, is primarily due to an increase in the amortization of excess deferred taxes. The increase in the ETR for Progress Energy for the six months ended June 30, 2019, is primarily due to a decrease in AFUDC equity in the current year. The decrease in the ETR for Duke Energy Progress for the three months ended June 30, 2019, is primarily due to an increase in the amortization of excess deferred taxes. The increase in the ETR for Duke Energy Florida for the three and six months ended June 30, 2019, is primarily due to a decrease in AFUDC equity in the current year. The decrease in the ETR for Duke Energy Ohio for the three months ended June 30, 2019, is primarily due to an increase in the amortization of excess deferred taxes. The decrease in the ETR for Duke Energy Indiana for the three and six months ended June 30, 2019, is primarily due to an increase in the amortization of excess deferred taxes. The decrease in the ETR for Piedmont for the three months ended June 30, 2019, is primarily due to lower state tax rates. The decrease in the ETR for the six months ended June 30, 2019, is primarily due to an increase in the amortization of excess deferred taxes.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2019
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS For information on subsequent events related to the Commercial Renewables segment, regulatory matters, commitments and contingencies and debt, see Notes 2, 3, 4 and 6, respectively.

Organization and Basis of Pre_2

Organization and Basis of Presentation (Policy)	6 Months Ended
	Jun. 30, 2019
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, 2018 . 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 13 for additional information on VIEs. These Condensed Consolidated Financial Statements also reflect the Duke Energy Registrants’ proportionate share of certain jointly owned generation and transmission facilities. NONCONTROLLING INTEREST Duke Energy maintains a controlling financial interest in certain less-than wholly owned non-regulated 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 HLBV method in allocating book profit 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 profit or loss allocated to each owner for the reporting period. During the second quarter of 2019, Duke Energy’s North Rosamond solar farm commenced commercial operations resulting in the allocation of losses to the noncontrolling tax equity members of $74 million utilizing the HLBV method. 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 13
New Accounting Standards	NEW ACCOUNTING STANDARDS Except as noted below, the new accounting standards adopted for 2018 and 2019 had no material impact on the presentation or results of operations, cash flows or financial position of the Duke Energy Registrants. Leases. In February 2016, the FASB issued revised accounting guidance for leases. The core principle of this guidance is that a lessee should recognize the assets and liabilities that arise from leases on the balance sheet. This resulted in a material impact on the presentation for the statement of financial position of the Duke Energy Registrants for the period ended June 30, 2019 , and an immaterial impact to the Duke Energy Registrants' results of operations for the three and six months ended June 30, 2019 , and cash flows for the six months ended June 30, 2019 . Duke Energy elected the modified retrospective method of adoption effective January 1, 2019. Under the modified retrospective method of adoption, prior year reported results are not restated. For adoption, Duke Energy has elected to apply the following practical expedients: Practical Expedient Description Package of transition practical expedients (for leases commenced prior to adoption date and must be adopted as a package) Do not need to 1) reassess whether any expired or existing contracts are/or contain leases, 2) reassess the lease classification for any expired or existing leases and 3) reassess initial direct costs for any existing leases. Short-term lease expedient (elect by class of underlying asset) Elect as an accounting policy to not apply the recognition requirements to short-term leases by asset class. Lease and non-lease components (elect by class of underlying asset) Elect as an accounting policy to not separate non-lease components from lease components and instead account for each lease and associated non-lease component as a single lease component by asset class. Hindsight expedient (when determining lease term) Elect to use hindsight to determine the lease term. Existing and expired land easements not previously accounted for as leases Elect to not evaluate existing or expired easements under the new guidance and carry forward current accounting treatment. Comparative reporting requirements for initial adoption Elect to apply transition requirements at adoption date, recognize cumulative effect adjustment to retained earnings in period of adoption and not apply the new requirements to comparative periods, including disclosures. Lessor expedient (elect by class of underlying asset) Elect as an accounting policy to aggregate non-lease components with the related lease component when specified conditions are met by asset class. Account for the combined component based on its predominant characteristic (revenue or operating lease). Duke Energy evaluated the financial statement impact of adopting the standard and monitored industry implementation issues. Under agreements considered leases, where Duke Energy is the lessee, for the use of certain aircraft, space on communication towers, industrial equipment, fleet vehicles, fuel transportation (barges and railcars), land, office space and PPAs are now recognized on the balance sheet. The Duke Energy Registrants did not have a material change to the financial statements from the adoption of the new standard for contracts where it is the lessor. See Note 5 for further information. No new accounting standards, issued but not yet adopted, are expected to have a material impact on the Duke Energy Registrants as of June 30, 2019 .
Environmental Costs	Liabilities are recorded when losses become probable and are reasonably estimable.Costs are typically expensed as Operation, maintenance and other on the Condensed Consolidated Statements of Operations unless regulatory recovery of the costs is deemed probable.
Derivatives	Duke Energy’s interest rate swaps for its regulated operations employ regulatory accounting. With regulatory accounting, the mark-to-market gains or losses on the swaps are deferred as regulatory liabilities or regulatory assets, respectively. Regulatory assets and liabilities are amortized consistent with the treatment of the related costs in the ratemaking process. The accrual of interest on the swaps is recorded as Interest Expense on the Duke Energy Registrant's Condensed Consolidated Statements of Operations and Comprehensive Income.
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 is other-than-temporarily impaired. The Duke Energy Registrants analyze all investment holdings each reporting period to determine whether a decline in fair value should be considered other-than-temporary. If an OTTI 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 considered OTTIs and 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 attributable 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 attributable 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.

Organization and Basis of Pre_3

Organization and Basis of Presentation (Tables)	6 Months Ended
	Jun. 30, 2019
Organization And Basis Of Presentation [Line Items]
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. June 30, 2019 December 31, 2018 Duke Duke Duke Progress Energy Duke Progress Energy Energy Energy Florida Energy Energy Florida Current Assets Cash and cash equivalents $ 336 $ 51 $ 16 $ 442 $ 67 $ 36 Other 106 31 31 141 39 39 Other Noncurrent Assets Other 39 38 — 8 6 — Total cash, cash equivalents and restricted cash $ 481 $ 120 $ 47 $ 591 $ 112 $ 75
Schedule of Utility Inventory	The components of inventory are presented in the tables below. June 30, 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 $ 2,252 $ 749 $ 1,036 $ 709 $ 327 $ 76 $ 323 $ 3 Coal 624 235 234 160 74 17 139 — Natural gas, oil and other fuel 313 41 210 111 98 31 1 30 Total inventory $ 3,189 $ 1,025 $ 1,480 $ 980 $ 499 $ 124 $ 463 $ 33 December 31, 2018 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 $ 2,238 $ 731 $ 1,049 $ 734 $ 315 $ 84 $ 312 $ 2 Coal 491 175 192 106 86 14 109 — Natural gas, oil and other fuel 355 42 218 114 103 28 1 68 Total inventory $ 3,084 $ 948 $ 1,459 $ 954 $ 504 $ 126 $ 422 $ 70
Schedule of New Accounting Pronouncements	Leases. In February 2016, the FASB issued revised accounting guidance for leases. The core principle of this guidance is that a lessee should recognize the assets and liabilities that arise from leases on the balance sheet. This resulted in a material impact on the presentation for the statement of financial position of the Duke Energy Registrants for the period ended June 30, 2019 , and an immaterial impact to the Duke Energy Registrants' results of operations for the three and six months ended June 30, 2019 , and cash flows for the six months ended June 30, 2019 . Duke Energy elected the modified retrospective method of adoption effective January 1, 2019. Under the modified retrospective method of adoption, prior year reported results are not restated. For adoption, Duke Energy has elected to apply the following practical expedients: Practical Expedient Description Package of transition practical expedients (for leases commenced prior to adoption date and must be adopted as a package) Do not need to 1) reassess whether any expired or existing contracts are/or contain leases, 2) reassess the lease classification for any expired or existing leases and 3) reassess initial direct costs for any existing leases. Short-term lease expedient (elect by class of underlying asset) Elect as an accounting policy to not apply the recognition requirements to short-term leases by asset class. Lease and non-lease components (elect by class of underlying asset) Elect as an accounting policy to not separate non-lease components from lease components and instead account for each lease and associated non-lease component as a single lease component by asset class. Hindsight expedient (when determining lease term) Elect to use hindsight to determine the lease term. Existing and expired land easements not previously accounted for as leases Elect to not evaluate existing or expired easements under the new guidance and carry forward current accounting treatment. Comparative reporting requirements for initial adoption Elect to apply transition requirements at adoption date, recognize cumulative effect adjustment to retained earnings in period of adoption and not apply the new requirements to comparative periods, including disclosures. Lessor expedient (elect by class of underlying asset) Elect as an accounting policy to aggregate non-lease components with the related lease component when specified conditions are met by asset class. Account for the combined component based on its predominant characteristic (revenue or operating lease).

Business Segments (Tables)

Business Segments (Tables)	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 Electric Gas Total Utilities and Utilities and Commercial Reportable (in millions) Infrastructure Infrastructure Renewables Segments Other Eliminations Total Unaffiliated revenues $ 5,467 $ 282 $ 118 $ 5,867 $ 6 $ — $ 5,873 Intersegment revenues 8 24 — 32 19 (51 ) — Total revenues $ 5,475 $ 306 $ 118 $ 5,899 $ 25 $ (51 ) $ 5,873 Segment income (loss) $ 809 $ 40 $ 86 $ 935 $ (115 ) $ — $ 820 Add back noncontrolling interests (a) (84 ) Add back preferred stock dividend 12 Net income $ 748 Segment assets $ 131,640 $ 12,943 $ 4,870 $ 149,453 $ 3,815 $ 181 $ 153,449 Three Months Ended June 30, 2018 Electric Gas Total Utilities and Utilities and Commercial Reportable (in millions) Infrastructure Infrastructure Renewables Segments Other Eliminations Total Unaffiliated revenues $ 5,215 $ 294 $ 119 $ 5,628 $ 15 $ — $ 5,643 Intersegment revenues 8 24 — 32 17 (49 ) — Total revenues $ 5,223 $ 318 $ 119 $ 5,660 $ 32 $ (49 ) $ 5,643 Segment income (loss) (b)(c) $ 575 $ 28 $ 38 $ 641 $ (136 ) $ — $ 505 Add back noncontrolling interests 2 Loss from discontinued operations, net of tax (5 ) Net income $ 502 Six Months Ended June 30, 2019 Electric Gas Total Utilities and Utilities and Reportable (in millions) Infrastructure Infrastructure Segments Other Total Total revenues $ 691 $ 273 $ 964 $ — $ 964 Segment income/Net (loss) income $ 67 $ 52 $ 119 $ (3 ) $ 116 Six Months Ended June 30, 2018 Electric Gas Total Utilities and Utilities and Reportable (in millions) Infrastructure Infrastructure Segments Other Total Total revenues $ 682 $ 277 $ 959 $ 24 $ 983 Segment income/Net (loss) income (a) $ 72 $ 52 $ 124 $ (103 ) $ 21 (a) Other includes the loss on the sale of Beckjord described above.
Duke Energy Ohio [Member]
Segment Reporting Information [Line Items]
Business Segment Data	Three Months Ended June 30, 2019 Electric Gas Total Utilities and Utilities and Reportable (in millions) Infrastructure Infrastructure Segments Other Total Total revenues $ 336 $ 97 $ 433 $ — $ 433 Segment income/Net (loss) income $ 31 $ 17 $ 48 $ (1 ) $ 47 Segment assets $ 5,914 $ 2,948 $ 8,862 $ 27 $ 8,889 Three Months Ended June 30, 2018 Electric Gas Total Utilities and Utilities and Reportable (in millions) Infrastructure Infrastructure Segments Other Total Total revenues $ 346 $ 103 $ 449 $ 10 $ 459 Segment income/Net (loss) income $ 39 $ 18 $ 57 $ (11 ) $ 46

Regulatory Matters (Tables)

Regulatory Matters (Tables)	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 , 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) 585 156 Duke Energy Indiana Gallagher Units 2 and 4 (b) 280 118 Gibson Units 1-5 (c) 3,132 1,960 Cayuga Units 1-2 (c) 1,005 983 Total Duke Energy 5,002 $ 3,217 (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)	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
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 $ 51 Duke Energy Carolinas 12 Duke Energy Ohio 29 Piedmont 2
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) June 30, 2019 December 31, 2018 Reserves for Legal Matters Duke Energy $ 64 $ 65 Duke Energy Carolinas 7 9 Progress Energy 55 54 Duke Energy Progress 14 12 Duke Energy Florida 24 24 Piedmont 1 1 The following tables contain 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. Six Months Ended June 30, 2019 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 $ 77 $ 11 $ 11 $ 4 $ 6 $ 48 $ 5 $ 2 Provisions/adjustments 9 4 3 2 1 2 — — Cash reductions (22 ) (3 ) (1 ) (1 ) — (18 ) — — Balance at end of period $ 64 $ 12 $ 13 $ 5 $ 7 $ 32 $ 5 $ 2 Six Months Ended June 30, 2018 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 $ 81 $ 10 $ 15 $ 3 $ 12 $ 47 $ 5 $ 2 Provisions/adjustments 1 2 2 2 (1 ) (3 ) 1 — Cash reductions (14 ) (1 ) (2 ) (1 ) (1 ) (9 ) (1 ) — Balance at end of period $ 68 $ 11 $ 15 $ 4 $ 10 $ 35 $ 5 $ 2

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Balance Sheet Amounts Recorded for Operating and Finance Leases	Adoption of the new standard resulted in the recording of ROU assets and operating lease liabilities as follows: As of January 1, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont ROU assets $ 1,750 $ 153 $ 863 $ 407 $ 456 $ 23 $ 61 $ 26 Operating lease liabilities – current 205 28 96 35 61 1 4 4 Operating lease liabilities – noncurrent 1,504 127 766 371 395 22 58 25 The following tables contain additional information related to leases. June 30, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Classification Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Assets Operating Operating lease ROU assets, net $ 1,735 $ 141 $ 839 $ 407 $ 432 $ 22 $ 60 $ 26 Finance Net property, plant and equipment 1,013 122 423 309 114 — 10 — Total lease assets $ 2,748 $ 263 $ 1,262 $ 716 $ 546 $ 22 $ 70 $ 26 Liabilities Current Operating Other current liabilities $ 213 $ 27 $ 100 $ 36 $ 64 $ 1 $ 4 $ 4 Finance Current maturities of long-term debt 115 6 23 6 17 — — — Noncurrent Operating Operating lease liabilities 1,502 117 747 377 370 21 56 25 Finance Long-Term Debt 907 101 394 304 90 — 10 — Total lease liabilities $ 2,737 $ 251 $ 1,264 $ 723 $ 541 $ 22 $ 70 $ 29
Lease Costs and Cash Flows Information	The following table presents the components of lease expense. Three Months Ended June 30, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Operating lease expense (a) $ 73 $ 11 $ 40 $ 17 $ 23 $ 3 $ 5 $ 2 Short-term lease expense (a) 6 2 4 2 2 1 — — Variable lease expense (a) 10 4 5 2 3 — — — Finance lease expense Amortization of leased assets (b) 29 1 5 1 4 1 — — Interest on lease liabilities (c) 20 3 13 10 3 — 1 — Total finance lease expense 49 4 18 11 7 1 1 — Total lease expense $ 138 $ 21 $ 67 $ 32 $ 35 $ 5 $ 6 $ 2 Six Months Ended June 30, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Operating lease expense (a) $ 145 $ 23 $ 82 $ 36 $ 46 $ 6 $ 10 $ 3 Short-term lease expense (a) 13 4 7 3 4 1 1 — Variable lease expense (a) 21 12 7 3 4 — — — Finance lease expense Amortization of leased assets (b) 56 2 8 2 6 1 — — Interest on lease liabilities (c) 37 7 19 14 5 — 1 — Total finance lease expense 93 9 27 16 11 1 1 — Total lease expense $ 272 $ 48 $ 123 $ 58 $ 65 $ 8 $ 12 $ 3 (a) Included in Operations, maintenance and other or, for barges and railcars, Fuel used in electric generation and purchased power on the Condensed Consolidated Statements of Operations. (b) Included in Depreciation and amortization on the Condensed Consolidated Statements of Operations. (c) Included in Interest Expense on the Condensed Consolidated Statements of Operations. Six Months Ended June 30, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Cash paid for amounts included in the measurement of lease liabilities (a) Operating cash flows from operating leases $ 136 $ 15 $ 60 $ 23 $ 37 $ 1 $ 3 $ 5 Operating cash flows from finance leases 37 7 19 14 5 — 1 — Financing cash flows from finance leases 56 2 8 2 6 1 — — Lease assets obtained in exchange for new lease liabilities (non-cash) Operating (b) $ 78 $ 2 $ 30 $ 30 $ — $ — $ — $ 1 Finance 175 — 175 175 — — — — (a) No amounts were classified as investing cash flows from operating leases for the six months ended June 30, 2019 . (b) Does not include ROU assets recorded as a result of the adoption of the new lease standard.
Schedule of Rent Expense	The following table presents rental expense for operating leases, as reported under the old lease standard. These amounts are included in Operation, maintenance and other and Fuel used in electric generation and purchased power on the Condensed Consolidated Statements of Operations. (in millions) Year Ended December 31, 2018 Duke Energy $ 268 Duke Energy Carolinas 49 Progress Energy 143 Duke Energy Progress 75 Duke Energy Florida 68 Duke Energy Ohio 13 Duke Energy Indiana 21 Piedmont 11
Lessee, Operating Lease, Liability, Maturity	The following table presents operating lease maturities and a reconciliation of the undiscounted cash flows to operating lease liabilities. Twelve Months Ended June 30, Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont 2020 $ 279 $ 33 $ 129 $ 51 $ 78 $ 2 $ 6 $ 5 2021 239 28 112 52 60 2 5 5 2022 199 19 94 40 54 2 4 5 2023 190 18 95 40 55 2 4 5 2024 178 15 96 41 55 2 4 5 Thereafter 1,055 61 513 306 207 22 65 7 Total operating lease payments 2,140 174 1,039 530 509 32 88 32 Less: present value discount (425 ) (30 ) (192 ) (117 ) (75 ) (10 ) (28 ) (3 ) Total operating lease liabilities (a) $ 1,715 $ 144 $ 847 $ 413 $ 434 $ 22 $ 60 $ 29 (a) Certain operating lease payments include renewal options that are reasonably certain to be exercised.
Schedule of Future Minimum Rental Payments for Operating Leases	The following table presents future minimum lease payments under operating leases, which at inception had a non-cancelable term of more than one year, as reported under the old lease standard. December 31, 2018 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont 2019 $ 239 $ 33 $ 97 $ 49 $ 48 $ 2 $ 6 $ 5 2020 219 29 90 46 44 2 5 5 2021 186 19 79 37 42 2 4 5 2022 170 19 76 34 42 2 4 5 2023 160 17 77 35 42 2 5 6 Thereafter 1,017 68 455 314 141 23 66 11 Total $ 1,991 $ 185 $ 874 $ 515 $ 359 $ 33 $ 90 $ 37
Maturities of Finance Lease Liabilities	The following table presents finance lease maturities and a reconciliation of the undiscounted cash flows to finance lease liabilities. Twelve Months Ended June 30, Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Indiana 2020 $ 177 $ 19 $ 69 $ 44 $ 25 $ 1 2021 183 17 69 44 25 1 2022 180 14 69 44 25 1 2023 171 14 69 44 25 1 2024 172 14 64 44 20 1 Thereafter 847 191 560 547 13 28 Total finance lease payments 1,730 269 900 767 133 33 Less: amounts representing interest (708 ) (162 ) (483 ) (457 ) (26 ) (23 ) Total finance lease liabilities $ 1,022 $ 107 $ 417 $ 310 $ 107 $ 10
Schedule of Future Minimum Lease Payments for Capital Leases	The following table presents future minimum lease payments under finance leases, as reported under the old lease standard. December 31, 2018 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana 2019 $ 170 $ 20 $ 45 $ 20 $ 25 $ 2 $ 1 2020 174 20 46 21 25 — 1 2021 177 15 45 20 25 — 1 2022 165 15 45 21 24 — 1 2023 165 15 45 21 24 — 1 Thereafter 577 204 230 209 21 — 27 Minimum annual payments 1,428 289 456 312 144 2 32 Less: amount representing interest (487 ) (180 ) (205 ) (175 ) (30 ) — (22 ) Total $ 941 $ 109 $ 251 $ 137 $ 114 $ 2 $ 10
Lessee, Lease, Supplemental Information	June 30, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Weighted-average remaining lease term (years) Operating leases 11 9 10 12 9 18 19 6 Finance leases 16 19 17 18 12 — 27 — Weighted-average discount rate (a) Operating leases 3.9 % 3.7 % 3.8 % 3.8 % 3.7 % 4.2 % 4.1 % 3.6 % Finance leases 7.9 % 12.9 % 11.8 % 12.4 % 8.3 % — % 11.9 % — % (a) The discount rate is calculated using the rate implicit in a lease if it is readily determinable. Generally, the rate used by the lessor is not provided to Duke Energy and in these cases the incremental borrowing rate is used. Duke Energy will typically use its fully collateralized incremental borrowing rate as of the commencement date to calculate and record the lease. The incremental borrowing rate is influenced by the lessee’s credit rating and lease term and as such may differ for individual leases, embedded leases or portfolios of leased assets.

Debt and Credit Facilities (Tab

Debt and Credit Facilities (Tables)	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	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 June 30, 2019 Unsecured Debt Duke Energy (Parent) September 2019 5.050 % $ 500 Duke Energy Kentucky October 2019 4.650 % 100 Progress Energy December 2019 4.875 % 350 Duke Energy (Parent) June 2020 2.100 % 330 First Mortgage Bonds Duke Energy Florida January 2020 1.850 % 250 Duke Energy Florida April 2020 4.550 % 250 Duke Energy Carolinas June 2020 4.300 % 450 Other (a) 468 Current maturities of long-term debt $ 2,698 (a) Includes finance lease obligations, amortizing debt and small bullet maturities. The following table summarizes significant debt issuances (in millions). Six Months Ended June 30, 2019 Duke Duke Duke Maturity Interest Duke Energy Energy Energy Issuance Date Date Rate Energy (Parent) Progress Ohio Piedmont Unsecured Debt March 2019 (a) March 2022 3.251 % (b) $ 300 $ 300 $ — $ — $ — March 2019 (a) March 2022 3.227 % 300 300 — — — May 2019 (e) June 2029 3.500 % 600 — — — 600 June 2019 (a) June 2029 3.400 % 600 600 — — — June 2019 (a) June 2049 4.200 % 600 600 — — — First Mortgage Bonds January 2019 (c) February 2029 3.650 % 400 — — 400 — January 2019 (c) February 2049 4.300 % 400 — — 400 — March 2019 (d) March 2029 3.450 % 600 — 600 — — Total issuances $ 3,800 $ 1,800 $ 600 $ 800 $ 600 (a) Debt issued to pay down short-term debt 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 April 2019, pay down short-term debt and for general corporate purposes. (d) Debt issued to fund eligible green energy projects in the Carolinas. (e) Debt issued to repay in full the outstanding $350 million Piedmont unsecured term loan due September 2019, pay down short-term debt and for general corporate purposes.
Schedule Of Line Of Credit Facilities	Other Credit Facilities June 30, 2019 (in millions) Facility size Amount drawn Duke Energy (Parent) Three-Year Revolving Credit Facility (a) $ 1,000 $ 500 Duke Energy Progress Term Loan Facility (b) 700 700 (a) In May 2019, Duke Energy (Parent) extended the termination date to May 2022. (b) $650 million was drawn under the term loan in January and February 2019. June 30, 2019 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 $ 1,750 $ 1,250 $ 800 $ 450 $ 600 $ 500 Reduction to backstop issuances Commercial paper (b) (3,420 ) (1,009 ) (1,099 ) (276 ) (474 ) (236 ) (326 ) — Outstanding letters of credit (53 ) (45 ) (4 ) (2 ) — — — (2 ) Tax-exempt bonds (81 ) — — — — — (81 ) — Coal ash set-aside (500 ) — (250 ) (250 ) — — — — Available capacity under the Master Credit Facility $ 3,946 $ 1,596 $ 397 $ 722 $ 326 $ 214 $ 193 $ 498 (a) Represents the sublimit of each borrower. (b) Duke Energy issued $625 million

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	6 Months Ended
	Jun. 30, 2019
Asset Retirement Obligation [Abstract]
Schedule of Asset Retirement Obligations	The following table presents the AROs recorded on the Condensed Consolidated Balance Sheets. June 30, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Decommissioning of nuclear power facilities (a) $ 5,807 $ 2,401 $ 3,265 $ 2,739 $ 526 $ — $ — $ — Closure of ash impoundments 6,498 2,894 2,858 2,839 19 47 699 — Other 323 47 70 38 32 42 20 19 Total ARO $ 12,628 $ 5,342 $ 6,193 $ 5,616 $ 577 $ 89 $ 719 $ 19 Less: current portion 739 203 416 413 3 6 115 — Total noncurrent ARO $ 11,889 $ 5,139 $ 5,777 $ 5,203 $ 574 $ 83 $ 604 $ 19 (a) Duke Energy amount includes purchase accounting adjustments related to the merger with Progress Energy.
Schedule of Change in Asset Retirement Obligation	The following table presents the change in liability associated with AROs for the Duke Energy Registrants. 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, 2018 (a) $ 10,467 $ 3,949 $ 5,411 $ 4,820 $ 591 $ 93 $ 722 $ 19 Accretion expense (b) 245 111 124 111 13 2 14 — Liabilities settled (c) (404 ) (155 ) (225 ) (197 ) (28 ) (6 ) (17 ) — Revisions in estimates of cash flows (d) 2,320 1,437 883 882 1 — — — Balance at June 30, 2019 $ 12,628 $ 5,342 $ 6,193 $ 5,616 $ 577 $ 89 $ 719 $ 19 (a) Primarily relates to decommissioning nuclear power facilities, closure of ash impoundments, asbestos removal, closure of landfills at fossil generation facilities, retirement of natural gas mains and removal of renewable energy generation assets. (b) For the six months ended June 30, 2019 , substantially all accretion expense relates to Duke Energy's regulated operations and has been deferred in accordance with regulatory accounting treatment. (c) Primarily relates to ash impoundment closures. (d) Relates to increases in closure estimates for certain ash impoundments as a result of the NCDEQ's April 1 Order. See Note 4 for more information. The incremental amount recorded represents the discounted cash flows for estimated closure costs based upon the probability weightings of the potential closure methods as evaluated on a site-by-site basis.
Public Utilities General Disclosures	(in millions) June 30, 2019 December 31, 2018 Duke Energy $ 6,327 $ 5,579 Duke Energy Carolinas 3,574 3,133 Duke Energy Progress 2,753 2,446

Goodwill (Tables)

Goodwill (Tables)	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 , and December 31, 2018 . 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)	6 Months Ended
	Jun. 30, 2019
Related Party Transaction [Line Items]
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 June 30, 2019 Intercompany income tax receivable $ — $ 25 $ — $ — $ 15 $ — $ 26 Intercompany income tax payable 76 — 41 19 — 1 — December 31, 2018 Intercompany income tax receivable $ 52 $ 47 $ 29 $ — $ — $ 8 $ — Intercompany income tax payable — — — 16 3 — 45 Three Months Ended June 30, Six Months Ended June 30, (in millions) 2019 2018 2019 2018 Duke Energy Carolinas Corporate governance and shared service expenses (a) $ 197 $ 213 $ 409 $ 433 Indemnification coverages (b) 5 5 10 11 JDA revenue (c) 17 19 40 53 JDA expense (c) 20 19 113 73 Intercompany natural gas purchases (d) 3 4 7 8 Progress Energy Corporate governance and shared service expenses (a) $ 183 $ 206 $ 359 $ 397 Indemnification coverages (b) 10 9 19 17 JDA revenue (c) 20 19 113 73 JDA expense (c) 17 19 40 53 Intercompany natural gas purchases (d) 19 19 38 38 Duke Energy Progress Corporate governance and shared service expenses (a) $ 108 $ 126 $ 214 $ 244 Indemnification coverages (b) 4 3 8 6 JDA revenue (c) 20 19 113 73 JDA expense (c) 17 19 40 53 Intercompany natural gas purchases (d) 19 19 38 38 Duke Energy Florida Corporate governance and shared service expenses (a) $ 75 $ 80 $ 145 $ 153 Indemnification coverages (b) 6 6 11 11 Duke Energy Ohio Corporate governance and shared service expenses (a) $ 83 $ 90 $ 168 $ 179 Indemnification coverages (b) 1 1 2 2 Duke Energy Indiana Corporate governance and shared service expenses (a) $ 93 $ 96 $ 190 $ 197 Indemnification coverages (b) 1 2 3 4 Piedmont Corporate governance and shared service expenses (a) $ 37 $ 40 $ 69 $ 76 Indemnification coverages (b) — — 1 1 Intercompany natural gas sales (d) 22 23 45 46 Natural gas storage and transportation costs (e) 6 6 11 12 (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)	6 Months Ended
	Jun. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Notional Amounts of Outstanding Derivative Positions	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. June 30, 2019 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Electricity (GWh) 33,135 — — — — 3,514 29,621 — Natural gas (millions of dekatherms) 740 133 173 173 — — 4 430 December 31, 2018 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Electricity (GWh) 15,286 — — — — 1,786 13,500 — Natural gas (millions of dekatherms) 739 121 169 166 3 — 1 448 The following table shows notional amounts of outstanding derivatives related to interest rate risk. June 30, 2019 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Cash flow hedges $ 959 $ — $ — $ — $ — $ — Undesignated contracts 1,427 600 800 250 550 27 Total notional amount (a) $ 2,386 $ 600 $ 800 $ 250 $ 550 $ 27 December 31, 2018 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Cash flow hedges $ 923 $ — $ — $ — $ — $ — Undesignated contracts 1,721 300 1,200 650 550 27 Total notional amount (a) $ 2,644 $ 300 $ 1,200 $ 650 $ 550 $ 27 (a) Duke Energy includes amounts related to consolidated VIEs of $659 million in cash flow hedges as of June 30, 2019 , and $422 million in cash flow hedges and $194 million in undesignated contracts as of December 31, 2018 .
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 June 30, 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 $ 37 $ — $ — $ — $ — $ 7 $ 29 $ 2 Total Derivative Assets – Commodity Contracts $ 37 $ — $ — $ — $ — $ 7 $ 29 $ 2 Interest Rate Contracts Designated as Hedging Instruments Noncurrent 1 — — — — — — — Total Derivative Assets – Interest Rate Contracts $ 1 $ — $ — $ — $ — $ — $ — $ — Total Derivative Assets $ 38 $ — $ — $ — $ — $ 7 $ 29 $ 2 Derivative Liabilities June 30, 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 $ 64 $ 31 $ 24 $ 24 $ — $ — $ 2 $ 7 Noncurrent 140 8 24 9 — — — 107 Total Derivative Liabilities – Commodity Contracts $ 204 $ 39 $ 48 $ 33 $ — $ — $ 2 $ 114 Interest Rate Contracts Designated as Hedging Instruments Current $ 4 $ — $ — $ — $ — $ — $ — $ — Noncurrent 32 — — — — — — — Not Designated as Hedging Instruments Current 86 54 31 2 29 1 — — Noncurrent 16 — 11 — 10 5 — — Total Derivative Liabilities – Interest Rate Contracts $ 138 $ 54 $ 42 $ 2 $ 39 $ 6 $ — $ — Total Derivative Liabilities $ 342 $ 93 $ 90 $ 35 $ 39 $ 6 $ 2 $ 114 Derivative Assets December 31, 2018 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 $ 35 $ 2 $ 2 $ 2 $ — $ 6 $ 23 $ 3 Noncurrent 4 1 2 2 — — — — Total Derivative Assets – Commodity Contracts $ 39 $ 3 $ 4 $ 4 $ — $ 6 $ 23 $ 3 Interest Rate Contracts Designated as Hedging Instruments Current $ 1 $ — $ — $ — $ — $ — $ — $ — Noncurrent 3 — — — — — — — Not Designated as Hedging Instruments Current 2 — — — — — — — Noncurrent 12 — — — — — — — Total Derivative Assets – Interest Rate Contracts $ 18 $ — $ — $ — $ — $ — $ — $ — Total Derivative Assets $ 57 $ 3 $ 4 $ 4 $ — $ 6 $ 23 $ 3 Derivative Liabilities December 31, 2018 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 $ 33 $ 14 $ 10 $ 5 $ 6 $ — $ — $ 8 Noncurrent 158 10 15 6 — — — 133 Total Derivative Liabilities – Commodity Contracts $ 191 $ 24 $ 25 $ 11 $ 6 $ — $ — $ 141 Interest Rate Contracts Designated as Hedging Instruments Current $ 12 $ — $ — $ — $ — $ — $ — $ — Noncurrent 6 — — — — — — — Not Designated as Hedging Instruments Current 23 9 13 11 2 1 — — Noncurrent 10 — 6 5 1 4 — — Total Derivative Liabilities – Interest Rate Contracts $ 51 $ 9 $ 19 $ 16 $ 3 $ 5 $ — $ — Total Derivative Liabilities $ 242 $ 33 $ 44 $ 27 $ 9 $ 5 $ — $ 141
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 June 30, 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 $ 37 $ — $ — $ — $ — $ 7 $ 29 $ 2 Gross amounts offset — — — — — — — — Net amounts presented in Current Assets: Other $ 37 $ — $ — $ — $ — $ 7 $ 29 $ 2 Noncurrent Gross amounts recognized $ 1 $ — $ — $ — $ — $ — $ — $ — Gross amounts offset — — — — — — — — Net amounts presented in Other Noncurrent Assets: Other $ 1 $ — $ — $ — $ — $ — $ — $ — Derivative Liabilities June 30, 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 $ 154 $ 85 $ 55 $ 26 $ 29 $ 1 $ 2 $ 7 Gross amounts offset (1 ) — (1 ) (1 ) — — — — Net amounts presented in Current Liabilities: Other $ 153 $ 85 $ 54 $ 25 $ 29 $ 1 $ 2 $ 7 Noncurrent Gross amounts recognized $ 188 $ 8 $ 35 $ 9 $ 10 $ 5 $ — $ 107 Gross amounts offset — — — — — — — — Net amounts presented in Other Noncurrent Liabilities: Other $ 188 $ 8 $ 35 $ 9 $ 10 $ 5 $ — $ 107 Derivative Assets December 31, 2018 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 $ 38 $ 2 $ 2 $ 2 $ — $ 6 $ 23 $ 3 Gross amounts offset (3 ) (2 ) (2 ) (2 ) — — — — Net amounts presented in Current Assets: Other $ 35 $ — $ — $ — $ — $ 6 $ 23 $ 3 Noncurrent Gross amounts recognized $ 19 $ 1 $ 2 $ 2 $ — $ — $ — $ — Gross amounts offset (3 ) (1 ) (2 ) (2 ) — — — — Net amounts presented in Other Noncurrent Assets: Other $ 16 $ — $ — $ — $ — $ — $ — $ — Derivative Liabilities December 31, 2018 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 $ 68 $ 23 $ 23 $ 16 $ 8 $ 1 $ — $ 8 Gross amounts offset (4 ) (2 ) (2 ) (2 ) — — — — Net amounts presented in Current Liabilities: Other $ 64 $ 21 $ 21 $ 14 $ 8 $ 1 $ — $ 8 Noncurrent Gross amounts recognized $ 174 $ 10 $ 21 $ 11 $ 1 $ 4 $ — $ 133 Gross amounts offset (3 ) (1 ) (2 ) (2 ) — — — — Net amounts presented in Other Noncurrent Liabilities: Other $ 171 $ 9 $ 19 $ 9 $ 1 $ 4 $ — $ 133
Offsetting Liabilities	Derivative Assets June 30, 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 $ 37 $ — $ — $ — $ — $ 7 $ 29 $ 2 Gross amounts offset — — — — — — — — Net amounts presented in Current Assets: Other $ 37 $ — $ — $ — $ — $ 7 $ 29 $ 2 Noncurrent Gross amounts recognized $ 1 $ — $ — $ — $ — $ — $ — $ — Gross amounts offset — — — — — — — — Net amounts presented in Other Noncurrent Assets: Other $ 1 $ — $ — $ — $ — $ — $ — $ — Derivative Liabilities June 30, 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 $ 154 $ 85 $ 55 $ 26 $ 29 $ 1 $ 2 $ 7 Gross amounts offset (1 ) — (1 ) (1 ) — — — — Net amounts presented in Current Liabilities: Other $ 153 $ 85 $ 54 $ 25 $ 29 $ 1 $ 2 $ 7 Noncurrent Gross amounts recognized $ 188 $ 8 $ 35 $ 9 $ 10 $ 5 $ — $ 107 Gross amounts offset — — — — — — — — Net amounts presented in Other Noncurrent Liabilities: Other $ 188 $ 8 $ 35 $ 9 $ 10 $ 5 $ — $ 107 Derivative Assets December 31, 2018 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 $ 38 $ 2 $ 2 $ 2 $ — $ 6 $ 23 $ 3 Gross amounts offset (3 ) (2 ) (2 ) (2 ) — — — — Net amounts presented in Current Assets: Other $ 35 $ — $ — $ — $ — $ 6 $ 23 $ 3 Noncurrent Gross amounts recognized $ 19 $ 1 $ 2 $ 2 $ — $ — $ — $ — Gross amounts offset (3 ) (1 ) (2 ) (2 ) — — — — Net amounts presented in Other Noncurrent Assets: Other $ 16 $ — $ — $ — $ — $ — $ — $ — Derivative Liabilities December 31, 2018 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 $ 68 $ 23 $ 23 $ 16 $ 8 $ 1 $ — $ 8 Gross amounts offset (4 ) (2 ) (2 ) (2 ) — — — — Net amounts presented in Current Liabilities: Other $ 64 $ 21 $ 21 $ 14 $ 8 $ 1 $ — $ 8 Noncurrent Gross amounts recognized $ 174 $ 10 $ 21 $ 11 $ 1 $ 4 $ — $ 133 Gross amounts offset (3 ) (1 ) (2 ) (2 ) — — — — Net amounts presented in Other Noncurrent Liabilities: Other $ 171 $ 9 $ 19 $ 9 $ 1 $ 4 $ — $ 133
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. June 30, 2019 Duke Duke Duke Energy Progress Energy (in millions) Energy Carolinas Energy Progress Aggregate fair value of derivatives in a net liability position $ 67 $ 34 $ 33 $ 33 Fair value of collateral already posted — — — — Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered 67 34 33 33 December 31, 2018 Duke Duke Duke Energy Progress Energy (in millions) Energy Carolinas Energy Progress Aggregate fair value of derivatives in a net liability position $ 44 $ 19 $ 25 $ 25 Fair value of collateral already posted — — — — Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered 44 19 25 25

Investments in Debt and Equit_2

Investments in Debt and Equity Securities (Tables)	6 Months Ended
	Jun. 30, 2019
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. June 30, 2019 December 31, 2018 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 $ — $ — $ 114 $ — $ — $ 88 Equity securities 3,076 36 5,178 2,402 95 4,475 Corporate debt securities 30 1 571 4 13 566 Municipal bonds 10 — 318 1 4 353 U.S. government bonds 34 1 1,270 14 12 1,076 Other debt securities 3 1 152 — 2 148 Total NDTF Investments $ 3,153 $ 39 $ 7,603 $ 2,421 $ 126 $ 6,706 Other Investments Cash and cash equivalents $ — $ — $ 49 $ — $ — $ 22 Equity securities 49 — 112 36 1 99 Corporate debt securities 2 — 60 — 2 60 Municipal bonds 3 1 90 — 1 85 U.S. government bonds 2 — 51 1 — 45 Other debt securities — — 65 — 1 58 Total Other Investments $ 56 $ 1 $ 427 $ 37 $ 5 $ 369 Total Investments $ 3,209 $ 40 $ 8,030 $ 2,458 $ 131 $ 7,075
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. June 30, 2019 December 31, 2018 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 $ — $ — $ 114 $ — $ — $ 88 Equity securities 3,076 36 5,178 2,402 95 4,475 Corporate debt securities 30 1 571 4 13 566 Municipal bonds 10 — 318 1 4 353 U.S. government bonds 34 1 1,270 14 12 1,076 Other debt securities 3 1 152 — 2 148 Total NDTF Investments $ 3,153 $ 39 $ 7,603 $ 2,421 $ 126 $ 6,706 Other Investments Cash and cash equivalents $ — $ — $ 49 $ — $ — $ 22 Equity securities 49 — 112 36 1 99 Corporate debt securities 2 — 60 — 2 60 Municipal bonds 3 1 90 — 1 85 U.S. government bonds 2 — 51 1 — 45 Other debt securities — — 65 — 1 58 Total Other Investments $ 56 $ 1 $ 427 $ 37 $ 5 $ 369 Total Investments $ 3,209 $ 40 $ 8,030 $ 2,458 $ 131 $ 7,075
Investments Classified by Contractual Maturity Date	The table below summarizes the maturity date for debt securities. June 30, 2019 Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Indiana Due in one year or less $ 365 $ 43 $ 315 $ 29 $ 286 $ 4 Due after one through five years 527 213 265 257 8 15 Due after five through 10 years 499 242 203 192 11 4 Due after 10 years 1,186 622 458 428 30 19 Total $ 2,577 $ 1,120 $ 1,241 $ 906 $ 335 $ 42
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 and six months ended June 30, 2019 , and 2018, were as follows. Three Months Ended Six Months Ended (in millions) June 30, 2019 June 30, 2018 June 30, 2019 June 30, 2018 FV-NI: Realized gains $ 66 $ 47 $ 101 $ 66 Realized losses 63 31 93 44 AFS: Realized gains 47 5 57 10 Realized losses 36 12 47 25
Duke Energy Carolinas [Member]
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. June 30, 2019 December 31, 2018 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 $ — $ — $ 41 $ — $ — $ 29 Equity securities 1,671 9 2,883 1,309 54 2,484 Corporate debt securities 18 1 360 2 9 341 Municipal bonds 2 — 63 — 1 81 U.S. government bonds 17 1 556 5 8 475 Other debt securities 3 1 141 — 2 143 Total NDTF Investments $ 1,711 $ 12 $ 4,044 $ 1,316 $ 74 $ 3,553
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. June 30, 2019 December 31, 2018 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 $ — $ — $ 41 $ — $ — $ 29 Equity securities 1,671 9 2,883 1,309 54 2,484 Corporate debt securities 18 1 360 2 9 341 Municipal bonds 2 — 63 — 1 81 U.S. government bonds 17 1 556 5 8 475 Other debt securities 3 1 141 — 2 143 Total NDTF Investments $ 1,711 $ 12 $ 4,044 $ 1,316 $ 74 $ 3,553
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 and six months ended June 30, 2019 , and 2018, were as follows. Three Months Ended Six Months Ended (in millions) June 30, 2019 June 30, 2018 June 30, 2019 June 30, 2018 FV-NI: Realized gains $ 44 $ 26 $ 67 $ 36 Realized losses 48 17 69 22 AFS: Realized gains 16 4 25 9 Realized losses 11 8 21 18
Progress Energy [Member]
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. June 30, 2019 December 31, 2018 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 $ — $ — $ 73 $ — $ — $ 59 Equity securities 1,405 27 2,295 1,093 41 1,991 Corporate debt securities 12 — 211 2 4 225 Municipal bonds 8 — 255 1 3 272 U.S. government bonds 17 — 714 9 4 601 Other debt securities — — 11 — — 5 Total NDTF Investments $ 1,442 $ 27 $ 3,559 $ 1,105 $ 52 $ 3,153 Other Investments Cash and cash equivalents $ — $ — $ 47 $ — $ — $ 17 Municipal bonds 3 — 50 — — 47 Total Other Investments $ 3 $ — $ 97 $ — $ — $ 64 Total Investments $ 1,445 $ 27 $ 3,656 $ 1,105 $ 52 $ 3,217
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. June 30, 2019 December 31, 2018 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 $ — $ — $ 73 $ — $ — $ 59 Equity securities 1,405 27 2,295 1,093 41 1,991 Corporate debt securities 12 — 211 2 4 225 Municipal bonds 8 — 255 1 3 272 U.S. government bonds 17 — 714 9 4 601 Other debt securities — — 11 — — 5 Total NDTF Investments $ 1,442 $ 27 $ 3,559 $ 1,105 $ 52 $ 3,153 Other Investments Cash and cash equivalents $ — $ — $ 47 $ — $ — $ 17 Municipal bonds 3 — 50 — — 47 Total Other Investments $ 3 $ — $ 97 $ — $ — $ 64 Total Investments $ 1,445 $ 27 $ 3,656 $ 1,105 $ 52 $ 3,217
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 and six months ended June 30, 2019 , and 2018, were as follows. Three Months Ended Six Months Ended (in millions) June 30, 2019 June 30, 2018 June 30, 2019 June 30, 2018 FV-NI: Realized gains $ 22 $ 21 $ 34 $ 30 Realized losses 15 14 24 22 AFS: Realized gains 30 1 31 1 Realized losses 25 4 26 7
Duke Energy Progress [Member]
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. June 30, 2019 December 31, 2018 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 $ — $ — $ 42 $ — $ — $ 46 Equity securities 1,092 24 1,886 833 30 1,588 Corporate debt securities 12 — 211 2 3 171 Municipal bonds 8 — 255 1 3 271 U.S. government bonds 16 — 429 6 3 415 Other debt securities — — 11 — — 3 Total NDTF Investments $ 1,128 $ 24 $ 2,834 $ 842 $ 39 $ 2,494 Other Investments Cash and cash equivalents $ — $ — $ 2 $ — $ — $ 6 Total Other Investments $ — $ — $ 2 $ — $ — $ 6 Total Investments $ 1,128 $ 24 $ 2,836 $ 842 $ 39 $ 2,500
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. June 30, 2019 December 31, 2018 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 $ — $ — $ 42 $ — $ — $ 46 Equity securities 1,092 24 1,886 833 30 1,588 Corporate debt securities 12 — 211 2 3 171 Municipal bonds 8 — 255 1 3 271 U.S. government bonds 16 — 429 6 3 415 Other debt securities — — 11 — — 3 Total NDTF Investments $ 1,128 $ 24 $ 2,834 $ 842 $ 39 $ 2,494 Other Investments Cash and cash equivalents $ — $ — $ 2 $ — $ — $ 6 Total Other Investments $ — $ — $ 2 $ — $ — $ 6 Total Investments $ 1,128 $ 24 $ 2,836 $ 842 $ 39 $ 2,500
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 and six months ended June 30, 2019 , and 2018, were as follows. Three Months Ended Six Months Ended (in millions) June 30, 2019 June 30, 2018 June 30, 2019 June 30, 2018 FV-NI: Realized gains $ 7 $ 17 $ 17 $ 25 Realized losses 7 12 15 20 AFS: Realized gains 1 1 2 1 Realized losses 1 3 2 5
Duke Energy Florida [Member]
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. June 30, 2019 December 31, 2018 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 $ — $ — $ 31 $ — $ — $ 13 Equity securities 313 3 409 260 11 403 Corporate debt securities — — — — 1 54 Municipal bonds — — — — — 1 U.S. government bonds 1 — 285 3 1 186 Other debt securities — — — — — 2 Total NDTF Investments (a) $ 314 $ 3 $ 725 $ 263 $ 13 $ 659 Other Investments Cash and cash equivalents $ — $ — $ 2 $ — $ — $ 1 Municipal bonds 3 — 50 — — 47 Total Other Investments $ 3 $ — $ 52 $ — $ — $ 48 Total Investments $ 317 $ 3 $ 777 $ 263 $ 13 $ 707 (a) During the six months ended June 30, 2019 , 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. June 30, 2019 December 31, 2018 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 $ — $ — $ 31 $ — $ — $ 13 Equity securities 313 3 409 260 11 403 Corporate debt securities — — — — 1 54 Municipal bonds — — — — — 1 U.S. government bonds 1 — 285 3 1 186 Other debt securities — — — — — 2 Total NDTF Investments (a) $ 314 $ 3 $ 725 $ 263 $ 13 $ 659 Other Investments Cash and cash equivalents $ — $ — $ 2 $ — $ — $ 1 Municipal bonds 3 — 50 — — 47 Total Other Investments $ 3 $ — $ 52 $ — $ — $ 48 Total Investments $ 317 $ 3 $ 777 $ 263 $ 13 $ 707 (a) During the six months ended June 30, 2019 , Duke Energy Florida continued to receive reimbursements from the NDTF for costs related to ongoing decommissioning activity of Crystal River Unit 3.
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 and six months ended June 30, 2019 , and 2018, were as follows. Three Months Ended Six Months Ended (in millions) June 30, 2019 June 30, 2018 June 30, 2019 June 30, 2018 FV-NI: Realized gains $ 15 $ 4 $ 17 $ 5 Realized losses 8 2 9 2 AFS: Realized gains 29 — 29 — Realized losses 24 1 24 2
Duke Energy Indiana [Member]
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. June 30, 2019 December 31, 2018 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 $ 37 $ — $ 74 $ 29 $ — $ 67 Corporate debt securities — — 7 — — 8 Municipal bonds — 1 34 — 1 33 U.S. government bonds — — 1 — — — Total Investments $ 37 $ 1 $ 116 $ 29 $ 1 $ 108
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. June 30, 2019 December 31, 2018 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 $ 37 $ — $ 74 $ 29 $ — $ 67 Corporate debt securities — — 7 — — 8 Municipal bonds — 1 34 — 1 33 U.S. government bonds — — 1 — — — Total Investments $ 37 $ 1 $ 116 $ 29 $ 1 $ 108

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2019
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 10 . See Note 11 for additional information related to investments by major security type for the Duke Energy Registrants. June 30, 2019 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not Categorized NDTF equity securities $ 5,178 $ 5,119 $ — $ — $ 59 NDTF debt securities 2,425 870 1,555 — — Other equity securities 112 112 — — — Other debt securities 315 99 216 — — Derivative assets 38 3 — 35 — Total assets 8,068 6,203 1,771 35 59 Derivative liabilities (342 ) (12 ) (216 ) (114 ) — Net assets (liabilities) $ 7,726 $ 6,191 $ 1,555 $ (79 ) $ 59 December 31, 2018 (in millions) Total Fair Value Level 1 Level 2 Level 3 Not Categorized NDTF equity securities $ 4,475 $ 4,410 $ — $ — $ 65 NDTF debt securities 2,231 576 1,655 — — Other equity securities 99 99 — — — Other debt securities 270 67 203 — — Derivative assets 57 4 25 28 — Total assets 7,132 5,156 1,883 28 65 Derivative liabilities (242 ) (11 ) (90 ) (141 ) — Net assets (liabilities) $ 6,890 $ 5,145 $ 1,793 $ (113 ) $ 65
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 June 30, Six Months Ended June 30, (in millions) 2019 2018 2019 2018 Balance at beginning of period $ (115 ) $ (124 ) $ (113 ) $ (114 ) Purchases, sales, issuances and settlements: Purchases 38 56 38 56 Settlements (11 ) (15 ) (23 ) (29 ) Total gains (losses) included on the Condensed Consolidated Balance Sheet 9 (14 ) 19 (10 ) Balance at end of period $ (79 ) $ (97 ) $ (79 ) $ (97 )
Quantitative Information Table - Level 3	The following tables include quantitative information about the Duke Energy Registrants' derivatives classified as Level 3. June 30, 2019 Fair Value Investment Type (in millions) Valuation Technique Unobservable Input Range Duke Energy Ohio FTRs $ 7 RTO auction pricing FTR price – per MWh $ 0.36 - $ 3.13 Duke Energy Indiana FTRs 28 RTO auction pricing FTR price – per MWh (0.59 ) - 7.61 Piedmont Natural gas contracts (114 ) Discounted cash flow Forward natural gas curves – price per MMBtu 1.96 - 3.21 Duke Energy Total Level 3 derivatives $ (79 ) December 31, 2018 Fair Value Investment Type (in millions) Valuation Technique Unobservable Input Range Duke Energy Ohio FTRs $ 6 RTO auction pricing FTR price – per MWh $ 1.19 - $ 4.59 Duke Energy Indiana FTRs 22 RTO auction pricing FTR price – per MWh (2.07 ) - 8.27 Piedmont Natural gas contracts (141 ) Discounted cash flow Forward natural gas curves – price per MMBtu 1.87 - 2.95 Duke Energy Total Level 3 derivatives $ (113 )
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. June 30, 2019 December 31, 2018 (in millions) Book Value Fair Value Book Value Fair Value Duke Energy (a) $ 57,040 $ 60,667 $ 54,529 $ 54,534 Duke Energy Carolinas 10,964 12,300 10,939 11,471 Progress Energy 19,199 21,408 18,911 19,885 Duke Energy Progress 9,049 9,707 8,204 8,300 Duke Energy Florida 7,213 8,173 7,321 7,742 Duke Energy Ohio 2,509 2,779 2,165 2,239 Duke Energy Indiana 3,723 4,363 3,782 4,158 Piedmont 2,384 2,576 2,138 2,180 (a) Book value of long-term debt includes $1.5 billion as of June 30, 2019 , and $1.6 billion as of December 31, 2018 , of unamortized debt discount and premium, net in 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 [Member]
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. June 30, 2019 (in millions) Total Fair Value Level 1 Level 2 Not Categorized NDTF equity securities $ 2,883 $ 2,824 $ — $ 59 NDTF debt securities 1,161 250 911 — Total assets 4,044 3,074 911 59 Derivative liabilities (93 ) — (93 ) — Net assets $ 3,951 $ 3,074 $ 818 $ 59 December 31, 2018 (in millions) Total Fair Value Level 1 Level 2 Not Categorized NDTF equity securities $ 2,484 $ 2,419 $ — $ 65 NDTF debt securities 1,069 149 920 — Derivative assets 3 — 3 — Total assets 3,556 2,568 923 65 Derivative liabilities (33 ) — (33 ) — Net assets $ 3,523 $ 2,568 $ 890 $ 65
Progress Energy [Member]
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. June 30, 2019 December 31, 2018 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 NDTF equity securities $ 2,295 $ 2,295 $ — $ 1,991 $ 1,991 $ — NDTF debt securities 1,264 620 644 1,162 427 735 Other debt securities 97 47 50 64 17 47 Derivative assets — — — 4 — 4 Total assets 3,656 2,962 694 3,221 2,435 786 Derivative liabilities (90 ) — (90 ) (44 ) — (44 ) Net assets $ 3,566 $ 2,962 $ 604 $ 3,177 $ 2,435 $ 742
Duke Energy Progress [Member]
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. June 30, 2019 December 31, 2018 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 NDTF equity securities $ 1,886 $ 1,886 $ — $ 1,588 $ 1,588 $ — NDTF debt securities 948 304 644 906 294 612 Other debt securities 2 2 — 6 6 — Derivative assets — — — 4 — 4 Total assets 2,836 2,192 644 2,504 1,888 616 Derivative liabilities (35 ) — (35 ) (27 ) — (27 ) Net assets $ 2,801 $ 2,192 $ 609 $ 2,477 $ 1,888 $ 589
Duke Energy Florida [Member]
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. June 30, 2019 December 31, 2018 (in millions) Total Fair Value Level 1 Level 2 Total Fair Value Level 1 Level 2 NDTF equity securities $ 409 $ 409 $ — $ 403 $ 403 $ — NDTF debt securities 316 316 — 256 133 123 Other debt securities 52 2 50 48 1 47 Total assets 777 727 50 707 537 170 Derivative liabilities (39 ) — (39 ) (9 ) — (9 ) Net assets $ 738 $ 727 $ 11 $ 698 $ 537 $ 161
Duke Energy Ohio [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	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 June 30, 2019 , and December 31, 2018 .
Reconciliation Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs
Duke Energy Indiana [Member]
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. June 30, 2019 December 31, 2018 (in millions) Total Fair Value Level 1 Level 2 Level 3 Total Fair Value Level 1 Level 2 Level 3 Other equity securities $ 74 $ 74 $ — $ — $ 67 $ 67 $ — $ — Other debt securities 42 — 42 — 41 — 41 — Derivative assets 29 1 — 28 23 1 — 22 Total assets $ 145 $ 75 $ 42 $ 28 $ 131 $ 68 $ 41 $ 22 Derivative liabilities (2 ) (2 ) — — — — — — Net assets $ 143 $ 73 $ 42 $ 28 $ 131 $ 68 $ 41 $ 22
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 June 30, Six Months Ended June 30, (in millions) 2019 2018 2019 2018 Balance at beginning of period $ 5 $ 7 $ 22 $ 27 Purchases, sales, issuances and settlements: Purchases 29 49 29 49 Settlements (9 ) (14 ) (19 ) (28 ) Total gains (losses) included on the Condensed Consolidated Balance Sheet 3 2 (4 ) (4 ) Balance at end of period $ 28 $ 44 $ 28 $ 44
Piedmont Natural Gas [Member]
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. June 30, 2019 December 31, 2018 (in millions) Total Fair Value Level 1 Level 3 Total Fair Value Level 1 Level 3 Derivative assets $ 2 $ 2 $ — $ 3 3 — Derivative liabilities (114 ) — (114 ) (141 ) — (141 ) Net (liabilities) assets $ (112 ) $ 2 $ (114 ) $ (138 ) $ 3 $ (141 )
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 June 30, Six Months Ended June 30, (in millions) 2019 2018 2019 2018 Balance at beginning of period $ (121 ) $ (132 ) $ (141 ) $ (142 ) Total gains (losses) and settlements 7 (18 ) 27 (8 ) Balance at end of period $ (114 ) $ (150 ) $ (114 ) $ (150 )

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	6 Months Ended
	Jun. 30, 2019
Variable Interest Entity, Primary Beneficiary [Member]
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 December 2020 December 2020 February 2021 April 2021 Credit facility amount $ 350 $ 475 $ 325 $ 250 Amounts borrowed at June 30, 2019 328 475 325 250 Amounts borrowed at December 31, 2018 325 450 300 225 Restricted Receivables at June 30, 2019 484 671 518 472 Restricted Receivables at December 31, 2018 564 699 547 357
Variable Interest Entity, Not Primary Beneficiary [Member]
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. June 30, 2019 Duke Energy Duke Duke Pipeline Commercial Other Energy Energy (in millions) Investments Renewables VIEs Total Ohio Indiana Receivables from affiliated companies $ — $ — $ — $ — $ 45 $ 81 Investments in equity method unconsolidated affiliates 1,066 187 52 1,305 — — Total assets $ 1,066 $ 187 $ 52 $ 1,305 $ 45 $ 81 Taxes accrued (2 ) — — (2 ) — — Other current liabilities — — 4 4 — — Deferred income taxes 48 — — 48 — — Other noncurrent liabilities — — 11 11 — — Total liabilities $ 46 $ — $ 15 $ 61 $ — $ — Net assets $ 1,020 $ 187 $ 37 $ 1,244 $ 45 $ 81 December 31, 2018 Duke Energy Duke Duke Pipeline Commercial Other Energy Energy (in millions) Investments Renewables VIEs Total Ohio Indiana Receivables from affiliated companies $ — $ — $ — $ — $ 93 $ 118 Investments in equity method unconsolidated affiliates 822 190 48 1,060 — — Total assets $ 822 $ 190 $ 48 $ 1,060 $ 93 $ 118 Taxes accrued (1 ) — — (1 ) — — Other current liabilities — — 4 4 — — Deferred income taxes 21 — — 21 — — Other noncurrent liabilities — — 12 12 — — Total liabilities $ 20 $ — $ 16 $ 36 $ — $ — Net assets $ 802 $ 190 $ 32 $ 1,024 $ 93 $ 118
DEFPF [Member] | Variable Interest Entity, Primary Beneficiary [Member]
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) June 30, 2019 December 31, 2018 Receivables of VIEs $ 8 $ 5 Regulatory Assets: Current 52 52 Current Assets: Other 31 39 Other Noncurrent Assets: Regulatory assets 1,019 1,041 Current Liabilities: Other 10 10 Current maturities of long-term debt 54 53 Long-Term Debt 1,082 1,111
Commercial Renewables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
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 renewables VIEs. (in millions) June 30, 2019 December 31, 2018 Current Assets: Other $ 109 $ 123 Property, plant and equipment, cost 4,419 4,007 Accumulated depreciation and amortization (769 ) (698 ) Other Noncurrent Assets: Other 289 261 Current maturities of long-term debt 178 174 Long-Term Debt 1,610 1,587 Other Noncurrent Liabilities: Asset Retirement Obligations 108 106 Other Noncurrent Liabilities: Other 222 212
Pipeline Investments [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
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 June 30, December 31, Entity Name Interest 2019 2018 ACP (a) 47 % $ 1,041 $ 797 Constitution 24 % 25 25 Total $ 1,066 $ 822 (a) Duke Energy evaluated this investment for impairment as of June 30, 2019 , and December 31, 2018 , and determined that fair value approximated carrying value and therefore no impairment was necessary.
Cinergy Receivables [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
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) June 30, 2019 December 31, 2018 June 30, 2019 December 31, 2018 Receivables sold $ 210 $ 269 $ 314 $ 336 Less: Retained interests 45 93 81 118 Net receivables sold $ 165 $ 176 $ 233 $ 218 The following table shows sales and cash flows related to receivables sold. Duke Energy Ohio Duke Energy Indiana Three Months Ended Six Months Ended Three Months Ended Six Months Ended June 30, June 30, June 30, June 30, (in millions) 2019 2018 2019 2018 2019 2018 2019 2018 Sales Receivables sold $ 429 $ 461 $ 1,004 $ 1,028 $ 676 $ 692 $ 1,410 $ 1,386 Loss recognized on sale 3 3 7 6 4 4 9 7 Cash flows Cash proceeds from receivables sold $ 448 $ 465 $ 1,045 $ 1,050 $ 680 $ 686 $ 1,438 $ 1,397 Collection fees received 1 1 1 1 1 1 1 1 Return received on retained interests 2 1 4 3 2 2 5 4

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction	Supplemental requirements contracts that include contracted blocks of energy and capacity at contractually fixed prices have the following estimated remaining performance obligations: Remaining Performance Obligations (in millions) 2019 2020 2021 2022 2023 Thereafter Total Progress Energy $ 63 $ 121 $ 87 $ 82 $ 39 $ 42 $ 434 Duke Energy Progress 4 9 9 9 9 9 49 Duke Energy Florida 59 112 78 73 30 33 385 Duke Energy Indiana 5 10 5 — — — 20 Remaining Performance Obligations (in millions) 2019 2020 2021 2022 2023 Thereafter Total Piedmont $ 34 $ 69 $ 65 $ 64 $ 61 $ 432 $ 725
Disaggregation of Revenue	Disaggregated revenues are presented as follows: Three Months Ended June 30, 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 $ 2,304 $ 679 $ 1,243 $ 496 $ 747 $ 159 $ 225 $ — General 1,584 531 750 339 411 105 197 — Industrial 759 289 231 164 67 36 201 — Wholesale 527 109 351 309 42 9 59 — Other revenues 187 68 99 44 55 25 27 — Total Electric Utilities and Infrastructure revenue from contracts with customers $ 5,361 $ 1,676 $ 2,674 $ 1,352 $ 1,322 $ 334 $ 709 $ — Gas Utilities and Infrastructure Residential $ 146 $ — $ — $ — $ — $ 64 $ — $ 82 Commercial 85 — — — — 26 — 59 Industrial 29 — — — — 3 — 24 Power Generation — — — — — — — 13 Other revenues 22 — — — — 2 — 19 Total Gas Utilities and Infrastructure revenue from contracts with customers $ 282 $ — $ — $ — $ — $ 95 $ — $ 197 Commercial Renewables Revenue from contracts with customers $ 46 $ — $ — $ — $ — $ — $ — $ — Other Revenue from contracts with customers $ 6 $ — $ — $ — $ — $ — $ — $ — Total revenue from contracts with customers $ 5,695 $ 1,676 $ 2,674 $ 1,352 $ 1,322 $ 429 $ 709 $ 197 Other revenue sources (a) $ 178 $ 37 $ 70 $ 35 $ 31 $ 4 $ 5 $ 12 Total revenues $ 5,873 $ 1,713 $ 2,744 $ 1,387 $ 1,353 $ 433 $ 714 $ 209 Three Months Ended June 30, 2018 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 $ 2,185 $ 659 $ 1,099 $ 452 $ 648 $ 181 $ 245 $ — General 1,481 501 678 300 377 110 188 — Industrial 736 286 224 159 66 33 192 — Wholesale 515 115 322 287 34 2 77 — Other revenues 194 85 96 47 50 23 20 — Total Electric Utilities and Infrastructure revenue from contracts with customers $ 5,111 $ 1,646 $ 2,419 $ 1,245 $ 1,175 $ 349 $ 722 $ — Gas Utilities and Infrastructure Residential $ 153 $ — $ — $ — $ — $ 66 $ — $ 87 Commercial 87 — — — — 28 — 59 Industrial 31 — — — — 3 — 28 Power Generation — — — — — — — 14 Other revenues 23 — — — — 6 — 17 Total Gas Utilities and Infrastructure revenue from contracts with customers $ 294 $ — $ — $ — $ — $ 103 $ — $ 205 Commercial Renewables Revenue from contracts with customers $ 47 $ — $ — $ — $ — $ — $ — $ — Other Revenue from contracts with customers $ 15 $ — $ — $ — $ — $ 10 $ — $ — Total revenue from contracts with customers $ 5,467 $ 1,646 $ 2,419 $ 1,245 $ 1,175 $ 462 $ 722 $ 205 Other revenue sources (a) $ 176 $ 26 $ 79 $ 46 $ 28 $ (3 ) $ 16 $ 10 Total revenues $ 5,643 $ 1,672 $ 2,498 $ 1,291 $ 1,203 $ 459 $ 738 $ 215 (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. Six Months Ended June 30, 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 $ 4,674 $ 1,439 $ 2,357 $ 1,032 $ 1,325 $ 348 $ 531 $ — General 3,011 1,027 1,382 645 737 208 394 — Industrial 1,470 555 453 325 128 69 391 — Wholesale 1,068 228 704 624 80 23 113 — Other revenues 359 146 271 169 102 41 44 — Total Electric Utilities and Infrastructure revenue from contracts with customers $ 10,582 $ 3,395 $ 5,167 $ 2,795 $ 2,372 $ 689 $ 1,473 $ — Gas Utilities and Infrastructure Residential $ 560 $ — $ — $ — $ — $ 176 $ — $ 384 Commercial 291 — — — — 75 — 216 Industrial 77 — — — — 10 — 66 Power Generation — — — — — — — 26 Other revenues 85 — — — — 10 — 75 Total Gas Utilities and Infrastructure revenue from contracts with customers $ 1,013 $ — $ — $ — $ — $ 271 $ — $ 767 Commercial Renewables Revenue from contracts with customers $ 88 $ — $ — $ — $ — $ — $ — $ — Other Revenue from contracts with customers $ 10 $ — $ — $ — $ — $ — $ — $ — Total Revenue from contracts with customers $ 11,693 $ 3,395 $ 5,167 $ 2,795 $ 2,372 $ 960 $ 1,473 $ 767 Other revenue sources (a) $ 343 $ 62 $ 149 $ 76 $ 67 $ 4 $ 9 $ 21 Total revenues $ 12,036 $ 3,457 $ 5,316 $ 2,871 $ 2,439 $ 964 $ 1,482 $ 788 Six Months Ended June 30, 2018 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 $ 4,535 $ 1,440 $ 2,211 $ 968 $ 1,243 $ 361 $ 523 $ — General 2,856 973 1,309 599 710 206 366 — Industrial 1,400 541 432 304 128 63 365 — Wholesale 1,148 234 768 684 84 2 145 — Other revenues 333 152 225 132 93 37 37 — Total Electric Utilities and Infrastructure revenue from contracts with customers $ 10,272 $ 3,340 $ 4,945 $ 2,687 $ 2,258 $ 669 $ 1,436 $ — Gas Utilities and Infrastructure Residential $ 566 $ — $ — $ — $ — $ 177 $ — $ 389 Commercial 288 — — — — 77 — 211 Industrial 79 — — — — 10 — 69 Power Generation — — — — — — — 27 Other revenues 78 — — — — 12 — 66 Total Gas Utilities and Infrastructure revenue from contracts with customers $ 1,011 $ — $ — $ — $ — $ 276 $ — $ 762 Commercial Renewables Revenue from contracts with customers $ 80 $ — $ — $ — $ — $ — $ — $ — Other Revenue from contracts with customers $ 31 $ — $ — $ — $ — $ 24 $ — $ — Total Revenue from contracts with customers $ 11,394 $ 3,340 $ 4,945 $ 2,687 $ 2,258 $ 969 $ 1,436 $ 762 Other revenue sources (a) $ 384 $ 95 $ 129 $ 64 $ 60 $ 14 $ 33 $ 6 Total revenues $ 11,778 $ 3,435 $ 5,074 $ 2,751 $ 2,318 $ 983 $ 1,469 $ 768 (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.
Schedule Of Unbilled Revenues With Restricted Receivables	Unbilled revenues are included within Receivables and Receivables of VIEs on the Condensed Consolidated Balance Sheets as shown in the following table. (in millions) June 30, 2019 December 31, 2018 Duke Energy $ 790 $ 896 Duke Energy Carolinas 288 313 Progress Energy 270 244 Duke Energy Progress 148 148 Duke Energy Florida 122 96 Duke Energy Ohio 1 2 Duke Energy Indiana 14 23 Piedmont 4 73 (in millions) June 30, 2019 December 31, 2018 Duke Energy Ohio $ 65 $ 86 Duke Energy Indiana 116 128

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2019
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 June 30, Six Months Ended June 30, (in millions, except per-share amounts) 2019 2018 2019 2018 Income from continuing operations attributable to Duke Energy common stockholders excluding impact of participating securities $ 819 $ 504 $ 1,718 $ 1,123 Weighted average common shares outstanding – basic 728 703 728 702 Equity Forwards — 1 — — Weighted average common shares outstanding – diluted 728 704 728 702 EPS from continuing operations attributable to Duke Energy common stockholders Basic and Diluted $ 1.12 $ 0.72 $ 2.36 $ 1.60 Potentially dilutive items excluded from the calculation (a) 2 2 2 2 Dividends declared per common share $ 0.928 $ 0.89 $ 1.855 $ 1.78 Dividends declared on preferred stock per depositary share $ 0.307 $ — $ 0.307 $ — (a) Performance stock awards were not included in the dilutive securities calculation because the performance measures related to the awards had not been met.

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	6 Months Ended
	Jun. 30, 2019
Qualified Pension Plan [Member]
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 June 30, 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 $ 10 $ 6 $ 6 $ 1 $ 2 $ 2 Interest cost on projected benefit obligation 82 21 26 12 13 4 7 3 Expected return on plan assets (143 ) (37 ) (45 ) (21 ) (22 ) (6 ) (10 ) (6 ) Amortization of actuarial loss 25 5 9 3 6 — 1 1 Amortization of prior service credit (8 ) (2 ) — (1 ) (1 ) — (1 ) (2 ) Net periodic pension costs $ (7 ) $ (1 ) $ — $ (1 ) $ 2 $ (1 ) $ (1 ) $ (2 ) Three Months Ended June 30, 2018 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Service cost $ 45 $ 15 $ 13 $ 8 $ 6 $ 1 $ 3 $ 2 Interest cost on projected benefit obligation 75 18 22 10 12 4 6 3 Expected return on plan assets (140 ) (37 ) (43 ) (21 ) (23 ) (7 ) (11 ) (6 ) Amortization of actuarial loss 33 7 11 5 6 1 2 3 Amortization of prior service credit (8 ) (2 ) (1 ) (1 ) (1 ) — — (3 ) Net periodic pension costs $ 5 $ 1 $ 2 $ 1 $ — $ (1 ) $ — $ (1 ) Six Months Ended June 30, 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 $ 74 $ 24 $ 21 $ 12 $ 10 $ 2 $ 4 $ 3 Interest cost on projected benefit obligation 165 41 52 24 27 9 13 6 Expected return on plan assets (286 ) (75 ) (89 ) (44 ) (44 ) (14 ) (21 ) (11 ) Amortization of actuarial loss 49 11 18 6 12 1 3 3 Amortization of prior service credit (16 ) (4 ) (1 ) (1 ) (1 ) — (1 ) (5 ) Net periodic pension costs $ (14 ) $ (3 ) $ 1 $ (3 ) $ 4 $ (2 ) $ (2 ) $ (4 ) Six Months Ended June 30, 2018 Duke Duke Duke Duke Duke Duke Energy Progress Energy Energy Energy Energy (in millions) Energy Carolinas Energy Progress Florida Ohio Indiana Piedmont Service cost $ 90 $ 30 $ 26 $ 15 $ 11 $ 2 $ 5 $ 4 Interest cost on projected benefit obligation 150 36 46 21 25 9 12 6 Expected return on plan assets (280 ) (74 ) (88 ) (42 ) (46 ) (14 ) (21 ) (12 ) Amortization of actuarial loss 66 14 22 10 12 2 4 6 Amortization of prior service credit (16 ) (4 ) (2 ) (1 ) (1 ) — — (6 ) Net periodic pension costs $ 10 $ 2 $ 4 $ 3 $ 1 $ (1 ) $ — $ (2 )

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Jun. 30, 2019
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 Six Months Ended June 30, June 30, 2019 2018 2019 2018 Duke Energy 15.9 % 16.5 % 12.6 % 19.9 % Duke Energy Carolinas 19.7 % 21.5 % 18.7 % 21.8 % Progress Energy 16.7 % 17.3 % 17.0 % 15.4 % Duke Energy Progress 16.3 % 20.1 % 17.1 % 16.8 % Duke Energy Florida 19.6 % 18.0 % 19.5 % 17.4 % Duke Energy Ohio 16.1 % 25.8 % 16.5 % 16.0 % Duke Energy Indiana 24.2 % 25.8 % 24.2 % 25.8 % Piedmont 22.2 % 27.3 % 21.8 % 23.9 %

Organization and Basis of Pre_4

Organization and Basis of Presentation (Schedule of Cash and Cash Equivalents) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Current Assets
Cash and cash equivalents	$ 336	$ 442
Other	106	141
Other Noncurrent Assets
Other	39	8
Total cash, cash equivalents and restricted cash	481	591	$ 427	$ 505
Progress Energy [Member]
Current Assets
Cash and cash equivalents	51	67
Other	31	39
Other Noncurrent Assets
Other	38	6
Total cash, cash equivalents and restricted cash	120	112	74	87
Duke Energy Florida [Member]
Current Assets
Cash and cash equivalents	16	36
Other	31	39
Other Noncurrent Assets
Total cash, cash equivalents and restricted cash	$ 47	$ 75	$ 45	$ 53

Organization and Basis of Pre_5

Organization and Basis of Presentation (Schedule of Inventory) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Public Utilities, Inventory [Line Items]
Inventory	$ 3,189	$ 3,084
Materials and supplies [Member]
Public Utilities, Inventory [Line Items]
Inventory	2,252	2,238
Coal [Member]
Public Utilities, Inventory [Line Items]
Inventory	624	491
Natural gas, oil and other fuel [Member]
Public Utilities, Inventory [Line Items]
Inventory	313	355
Duke Energy Carolinas [Member]
Public Utilities, Inventory [Line Items]
Inventory	1,025	948
Duke Energy Carolinas [Member] | Materials and supplies [Member]
Public Utilities, Inventory [Line Items]
Inventory	749	731
Duke Energy Carolinas [Member] | Coal [Member]
Public Utilities, Inventory [Line Items]
Inventory	235	175
Duke Energy Carolinas [Member] | Natural gas, oil and other fuel [Member]
Public Utilities, Inventory [Line Items]
Inventory	41	42
Progress Energy [Member]
Public Utilities, Inventory [Line Items]
Inventory	1,480	1,459
Progress Energy [Member] | Materials and supplies [Member]
Public Utilities, Inventory [Line Items]
Inventory	1,036	1,049
Progress Energy [Member] | Coal [Member]
Public Utilities, Inventory [Line Items]
Inventory	234	192
Progress Energy [Member] | Natural gas, oil and other fuel [Member]
Public Utilities, Inventory [Line Items]
Inventory	210	218
Duke Energy Progress [Member]
Public Utilities, Inventory [Line Items]
Inventory	980	954
Duke Energy Progress [Member] | Materials and supplies [Member]
Public Utilities, Inventory [Line Items]
Inventory	709	734
Duke Energy Progress [Member] | Coal [Member]
Public Utilities, Inventory [Line Items]
Inventory	160	106
Duke Energy Progress [Member] | Natural gas, oil and other fuel [Member]
Public Utilities, Inventory [Line Items]
Inventory	111	114
Duke Energy Florida [Member]
Public Utilities, Inventory [Line Items]
Inventory	499	504
Duke Energy Florida [Member] | Materials and supplies [Member]
Public Utilities, Inventory [Line Items]
Inventory	327	315
Duke Energy Florida [Member] | Coal [Member]
Public Utilities, Inventory [Line Items]
Inventory	74	86
Duke Energy Florida [Member] | Natural gas, oil and other fuel [Member]
Public Utilities, Inventory [Line Items]
Inventory	98	103
Duke Energy Ohio [Member]
Public Utilities, Inventory [Line Items]
Inventory	124	126
Duke Energy Ohio [Member] | Materials and supplies [Member]
Public Utilities, Inventory [Line Items]
Inventory	76	84
Duke Energy Ohio [Member] | Coal [Member]
Public Utilities, Inventory [Line Items]
Inventory	17	14
Duke Energy Ohio [Member] | Natural gas, oil and other fuel [Member]
Public Utilities, Inventory [Line Items]
Inventory	31	28
Duke Energy Indiana [Member]
Public Utilities, Inventory [Line Items]
Inventory	463	422
Duke Energy Indiana [Member] | Materials and supplies [Member]
Public Utilities, Inventory [Line Items]
Inventory	323	312
Duke Energy Indiana [Member] | Coal [Member]
Public Utilities, Inventory [Line Items]
Inventory	139	109
Duke Energy Indiana [Member] | Natural gas, oil and other fuel [Member]
Public Utilities, Inventory [Line Items]
Inventory	1	1
Piedmont Natural Gas [Member]
Public Utilities, Inventory [Line Items]
Inventory	33	70
Piedmont Natural Gas [Member] | Materials and supplies [Member]
Public Utilities, Inventory [Line Items]
Inventory	3	2
Piedmont Natural Gas [Member] | Natural gas, oil and other fuel [Member]
Public Utilities, Inventory [Line Items]
Inventory	$ 30	$ 68

Organization and Basis of Pre_6

Organization and Basis of Presentation (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Noncontrolling Interest [Line Items]
Allocation of losses to noncontrolling interest	$ (84)	$ 2	$ (91)	$ 4
North Rosamond Solar Farm [Member]
Noncontrolling Interest [Line Items]
Allocation of losses to noncontrolling interest	$ 74

Business Segments (Narrative) (

Business Segments (Narrative) (Details) $ in Millions	Apr. 24, 2019USD ($)asset	Jun. 30, 2019USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2019USD ($)segment	Jun. 30, 2018USD ($)
Segment Reporting Information [Line Items]
Pretax (gain) loss on disposal		$ (3)	$ (3)		$ 97
Operation, maintenance and other		1,434	1,544	$ 2,853	3,008
Duke Energy Ohio [Member]
Segment Reporting Information [Line Items]
Pretax (gain) loss on disposal					106
Operation, maintenance and other		123	$ 130	$ 255	$ 261
Number of reportable segments | segment				2
Beckjord [Member]
Segment Reporting Information [Line Items]
Pretax (gain) loss on disposal				$ (106)
Operation, maintenance and other				1
Certain Renewable Assets [Member] | Commercial Renewables [Member]
Segment Reporting Information [Line Items]
Pretax proceeds from sale	$ 415
Operating Wind, Solar and Battery Storage Assets [Member] | Commercial Renewables [Member]
Segment Reporting Information [Line Items]
Ownership percent divested	49.00%
Assets divested | asset	37
Operating Solar assets [Member] | Commercial Renewables [Member]
Segment Reporting Information [Line Items]
Ownership percent divested	33.00%
Assets divested | asset	11
Renewable Merchant Plants [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net		$ 160		$ 160

Business Segments (Business Seg

Business Segments (Business Segment Data) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Loss From Discontinued Operations, net of tax		$ (5)	$ 0	$ (5)
Operating revenues	$ 5,873	5,643	12,036	11,778
Segment income (loss)	820	505	1,720	1,125
Add back noncontrolling interests(a)	(84)	2	(91)	4
Add back preferred stock dividend	12		12
Net Income	748	502	1,641	1,124
Net income (attributable to parent)	820	500	1,720	1,120
Segment assets	153,449		153,449		$ 145,392
Electric Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	5,467	5,215	10,788	10,530
Gas Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	282	294	1,014	997
Commercial Renewables [Member]
Segment Reporting Information [Line Items]
Operating revenues	118	119	224	220
Total Reportable Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	5,867	5,628	12,026	11,747
Other [Member]
Segment Reporting Information [Line Items]
Operating revenues	6	15	10	31
Operating Segments [Member]
Segment Reporting Information [Line Items]
Segment income (loss)	935	641	1,924	1,527
Segment assets	149,453		149,453
Operating Segments [Member] | Electric Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	5,475	5,223	10,804	10,546
Segment income (loss)	809	575	1,559	1,325
Segment assets	131,640		131,640
Operating Segments [Member] | Gas Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	306	318	1,062	1,045
Segment income (loss)	40	28	266	144
Segment assets	12,943		12,943
Operating Segments [Member] | Commercial Renewables [Member]
Segment Reporting Information [Line Items]
Operating revenues	118	119	224	220
Segment income (loss)	86	38	99	58
Segment assets	4,870		4,870
Operating Segments [Member] | Total Reportable Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	5,899	5,660	12,090	11,811
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenues	(51)	(49)	(100)	(100)
Segment assets	181		181
Intersegment Eliminations [Member] | Electric Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	8	8	16	16
Intersegment Eliminations [Member] | Gas Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	24	24	48	48
Intersegment Eliminations [Member] | Total Reportable Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	32	32	64	64
Intersegment Eliminations [Member] | Other [Member]
Segment Reporting Information [Line Items]
Operating revenues	19	17	36	36
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Segment income (loss)	(115)	(136)	(204)	(402)
Segment assets	3,815		3,815
Corporate, Non-Segment [Member] | Other [Member]
Segment Reporting Information [Line Items]
Operating revenues	25	32	46	67
Duke Energy Ohio [Member]
Segment Reporting Information [Line Items]
Operating revenues	433	459	964	983
Segment income (loss)	47	46	116	21
Net income (attributable to parent)	47	46	116	21
Segment assets	8,889		8,889		$ 8,555
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	336	346	691	682
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	97	103	273	277
Duke Energy Ohio [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	433	449	964	959
Segment income (loss)	48	57	119	124
Segment assets	8,862		8,862
Duke Energy Ohio [Member] | Operating Segments [Member] | Electric Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Segment income (loss)	31	39	67	72
Segment assets	5,914		5,914
Duke Energy Ohio [Member] | Operating Segments [Member] | Gas Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Segment income (loss)	17	18	52	52
Segment assets	2,948		2,948
Duke Energy Ohio [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating revenues		10		24
Segment income (loss)	(1)	$ (11)	(3)	$ (103)
Segment assets	$ 27		$ 27

Regulatory Matters (Narrative)

Regulatory Matters (Narrative) (Details) $ in Millions	Jul. 02, 2019USD ($)	Jun. 13, 2019USD ($)	May 29, 2019USD ($)	May 21, 2019USD ($)	Apr. 02, 2019USD ($)	Apr. 01, 2019USD ($)	Mar. 25, 2019USD ($)	Jan. 30, 2019USD ($)	Dec. 27, 2018USD ($)	Nov. 08, 2018USD ($)	Oct. 30, 2018USD ($)	Aug. 31, 2018USD ($)	Jul. 31, 2018USD ($)	Jun. 22, 2018USD ($)	May 31, 2018USD ($)	Apr. 13, 2018USD ($)	Feb. 28, 2018	Feb. 15, 2018USD ($)	Nov. 22, 2017	Sep. 27, 2017USD ($)	Sep. 26, 2017USD ($)	Aug. 25, 2017USD ($)	Jun. 01, 2017USD ($)	Jun. 30, 2016	Dec. 22, 2015	Jan. 05, 2015	Sep. 02, 2014	Nov. 30, 2018USD ($)	May 31, 2018USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2015USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Jun. 30, 2019USD ($)MW	Jun. 30, 2018USD ($)	Dec. 31, 2017USD ($)	Jul. 12, 2019USD ($)	Apr. 30, 2019USD ($)	Jan. 28, 2019USD ($)	Dec. 31, 2018USD ($)	Oct. 31, 2018customer	Sep. 28, 2018USD ($)	Mar. 28, 2018USD ($)	Sep. 30, 2017customer
Public Utilities, General Disclosures [Line Items]
Operation, maintenance and other																																$ 1,434	$ 1,544		$ 2,853	$ 3,008
Loss before income taxes																																(889)	(607)		(1,877)	(1,410)
Public utilities, property, plant and equipment, net																																97,198			97,198						$ 91,694
Regulated operating revenue, electric, non-nuclear																																5,423	5,178		$ 10,708	10,462
Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW																																			5,002
Public utilities, property, plant and equipment, net																																$ 3,217			$ 3,217
Atlantic Coast Pipeline (ACP) [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage																											47.00%
Long-term purchase commitment, period																											20 years
Constitution Pipeline [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage																																24.00%			24.00%
Estimated contributions																																$ 229			$ 229
Equity method investment, OTTI																																				55
Dominion Resources [Member] | Atlantic Coast Pipeline (ACP) [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage																											48.00%
Southern Company Gas [Member] | Atlantic Coast Pipeline (ACP) [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage																											5.00%
Williams Partners L.P. [Member] | Constitution Pipeline [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage																																41.00%			41.00%
Minimum [Member] | Atlantic Coast Pipeline (ACP) [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost																																$ 7,000			$ 7,000
Maximum [Member] | Atlantic Coast Pipeline (ACP) [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost																																7,800			7,800
Hurricane Florence, Hurricane Michael And Winter Storm Diego Damages [Member]
Public Utilities, General Disclosures [Line Items]
Operation, maintenance and other					$ 553
Estimated capital cost					96
Duke Energy Carolinas [Member]
Public Utilities, General Disclosures [Line Items]
Operation, maintenance and other																																441	499		881	950
Loss before income taxes																																(375)	(149)		(731)	(563)
Public utilities, property, plant and equipment, net																																31,202			31,202						29,245
Duke Energy Carolinas [Member] | Hurricane Florence, Hurricane Michael And Winter Storm Diego Damages [Member]
Public Utilities, General Disclosures [Line Items]
Operation, maintenance and other					171
Estimated capital cost					20
Duke Energy Carolinas [Member] | 2017 North Carolina Rate Case [Member] | NCUC [Member]
Public Utilities, General Disclosures [Line Items]
Operation, maintenance and other																																		$ 4
Utilities operating expense														$ 150
Penalty assessed														70
Reduction of annual recovery of deferred coal ash costs														$ 14
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%
Regulatory asset, amortization period														5 years
Loss before income taxes																																		14
Duke Energy Carolinas [Member] | South Carolina Rate Case 2018 [Member] | PSCSC [Member]
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount										$ 168
Requested rate increase, percentage										10.00%
Public utilities, approved equity capital structure, percentage				53.00%
Public utilities, approved debt capital structure, percentage				47.00%
Approved return on equity percentage				9.50%
Change in tax rate, deferred tax liability, income tax benefit				$ 66						$ 66
Measurement period adjustment, income tax expense (benefit)				45						46
Duke Energy Carolinas [Member] | South Carolina Rate Case 2018 [Member] | PSCSC [Member] | Asset retirement obligations - coal ash [Member]
Public Utilities, General Disclosures [Line Items]
Recovery costs denied				115
Regulatory assets				$ 96						$ 242
Regulatory asset, amortization period				5 years						5 years
Duke Energy Carolinas [Member] | South Carolina Rate Case 2018 [Member] | PSCSC [Member] | Deferred Project Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets				$ 125
Regulatory asset, amortization period				12 years
Duke Energy Carolinas [Member] | FERC Formula Rate Matter [Member] | FERC [Member]
Public Utilities, General Disclosures [Line Items]
Customer refundable fees, refund payments																		$ 25
Duke Energy Carolinas [Member] | 2018 Sale of Hydro Plants [Member] | NCUC [Member]
Public Utilities, General Disclosures [Line Items]
Estimated loss on asset sale																													$ 40
Duke Energy Progress [Member]
Public Utilities, General Disclosures [Line Items]
Operation, maintenance and other																																357	375		692	756
Loss before income taxes																																(202)	(174)		(449)	(380)
Public utilities, property, plant and equipment, net																																21,877			$ 21,877						20,398
Duke Energy Progress [Member] | Asheville Plant [Member] | Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW																																			376
Public utilities, property, plant and equipment, net																																284			$ 284						327
Duke Energy Progress [Member] | Hurricane Florence, Hurricane Michael And Winter Storm Diego Damages [Member]
Public Utilities, General Disclosures [Line Items]
Operation, maintenance and other					382
Estimated capital cost					$ 76
Duke Energy Progress [Member] | 2017 North Carolina Rate Case [Member] | NCUC [Member]
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount																							$ 477
Requested rate increase, percentage																							14.90%
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%
Requested rate increase (decrease), amended amount																							$ 420
Requested rate increase (decrease) amended, percentage																							13.00%
Loss before income taxes																																		$ 68
Duke Energy Progress [Member] | South Carolina Rate Case 2018 [Member] | PSCSC [Member]
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount										$ 59
Requested rate increase, percentage										10.30%
Public utilities, approved equity capital structure, percentage				53.00%
Public utilities, approved debt capital structure, percentage				47.00%
Approved return on equity percentage				9.50%
Change in tax rate, deferred tax liability, income tax benefit				$ 17						$ 17
Measurement period adjustment, income tax expense (benefit)				12						10
Duke Energy Progress [Member] | South Carolina Rate Case 2018 [Member] | PSCSC [Member] | Asset retirement obligations - coal ash [Member]
Public Utilities, General Disclosures [Line Items]
Recovery costs denied				65
Regulatory assets				$ 4						$ 51
Regulatory asset, amortization period				5 years						5 years
Duke Energy Progress [Member] | Western Carolinas Modernization Plan [Member] | NCUC [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost																																												$ 893
Regulatory asset, amortization period																																			10 years
Duke Energy Florida [Member]
Public Utilities, General Disclosures [Line Items]
Operation, maintenance and other																																244	237		$ 474	474
Loss before income taxes																																(250)	(205)		(369)	(328)
Public utilities, property, plant and equipment, net																																14,388			14,388						13,824
Duke Energy Florida [Member] | Storm Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets																																118			118						217
Duke Energy Florida [Member] | Storm Restoration Cost Recovery [Member]
Public Utilities, General Disclosures [Line Items]
Customers experiencing outages | customer																																													1,000,000
Operation, maintenance and other		$ 6
Decrease in storm reserve		24
Allowed storm reserve															$ 132														132
Property, plant and equipment, net		$ 18
Duke Energy Florida [Member] | Storm Restoration Cost Recovery [Member] | FPSC [Member]
Public Utilities, General Disclosures [Line Items]
Estimated storm costs - capital and operation maintenance															510														510											$ 508
Duke Energy Florida [Member] | Hurricane Michael Storm Damage [Member]
Public Utilities, General Disclosures [Line Items]
Customers experiencing outages | customer																																										72,000
Estimated storm costs - capital and operation maintenance																																360			360				$ 221
Property, plant and equipment, net																																82			82						35
Duke Energy Florida [Member] | Federal Tax Act Impacts [Member] | FPSC [Member]
Public Utilities, General Disclosures [Line Items]
Tax act annual savings									$ 4						134
Tax act excess deferred tax amortization requested rate decrease, amount									71						67
Duke Energy Florida [Member] | Federal Tax Act Impacts Revenue Requirement [Member] | FPSC [Member]
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount															201
Duke Energy Florida [Member] | Federal Tax Act Impacts Revenue Requirement [Member] | FPSC [Member] | Storm Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets									$ 155						151														151
Duke Energy Florida [Member] | Federal Tax Act Impacts Revenue Requirement [Member] | Crystal River Units 3 and 4 [Member] | FPSC [Member]
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net															$ 50														$ 50
Duke Energy Florida [Member] | 2017 Second Revised and Restated Stipulation and Settlement Agreement [Member] | Hamilton Project [Member] | FPSC [Member]
Public Utilities, General Disclosures [Line Items]
Approved rate increase (decrease), amount											$ 15
Duke Energy Florida [Member] | 2017 Second Revised and Restated Stipulation and Settlement Agreement [Member] | Columbia Project [Member] | FPSC [Member]
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount													$ 14
Duke Energy Florida [Member] | 2017 Second Revised and Restated Stipulation and Settlement Agreement [Member] | Trenton Generation Project [Member] | FPSC [Member]
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount							$ 13
Duke Energy Florida [Member] | 2017 Second Revised and Restated Stipulation and Settlement Agreement [Member] | Lake Placid Generation Project [Member] | FPSC [Member]
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount							8
Duke Energy Florida [Member] | 2017 Second Revised and Restated Stipulation and Settlement Agreement [Member] | DeBary Solar Project [Member] | FPSC [Member]
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount							$ 11
Duke Energy Ohio [Member]
Public Utilities, General Disclosures [Line Items]
Operation, maintenance and other																																123	130		255	261
Loss before income taxes																																(56)	(62)		(139)	(25)
Public utilities, property, plant and equipment, net																																7,015			7,015						6,643
Regulated operating revenue, electric, non-nuclear																																336	346		691	682
Duke Energy Ohio [Member] | Ohio Base Rate Case 2017 [Member] | PUCO [Member]
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount																														$ 15
Requested return on equity, percent																														10.40%
Public utilities, requested equity capital structure, percentage																50.75%
Public utilities, requested debt capital structure, percentage																49.25%
Approved rate increase (decrease), amount																$ (20)
Requested rate increase (decrease), amended amount																$ (19)
Requested rate increase (decrease) amended, percentage																9.84%
Duke Energy Ohio [Member] | Ohio Base Rate Case 2017 [Member] | PUCO [Member] | Minimum [Member]
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount																					$ (18)
Requested return on equity, percent																					9.22%
Duke Energy Ohio [Member] | Ohio Base Rate Case 2017 [Member] | PUCO [Member] | Maximum [Member]
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount																					$ (29)
Requested return on equity, percent																					10.24%
Requested Rider Revenue Increase																$ 10
Duke Energy Ohio [Member] | Energy Efficiency Cost Recovery [Member] | PUCO [Member]
Public Utilities, General Disclosures [Line Items]
Regulated operating revenue, electric, non-nuclear																															$ 20
Duke Energy Ohio [Member] | Energy Efficiency Cost Recovery [Member] | PUCO [Member] | Maximum [Member]
Public Utilities, General Disclosures [Line Items]
Approved rate increase (decrease), amount																				$ 38
Approved rate increase (decrease), one-time waiver amount																																					$ 56
Duke Energy Ohio [Member] | Natural Gas Pipeline Extension [Member] | OPSB [Member] | Minimum [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost excluding AFUDC																																163			163
Duke Energy Ohio [Member] | Natural Gas Pipeline Extension [Member] | OPSB [Member] | Maximum [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost excluding AFUDC																																245			245
Duke Energy Ohio [Member] | MGP Cost Recovery - 2009 Through 2012 [Member] | PUCO [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets																																55			55
Duke Energy Ohio [Member] | MGP Cost Recovery - 2013 Through 2017 [Member] | PUCO [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets																																											$ 26
Duke Energy Ohio [Member] | MGP Cost Recovery - 2013 Through 2017 [Member] | PUCO [Member] | MGP Costs - Regulatory Disallowance [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets																																											$ 12
Duke Energy Ohio [Member] | MGP Cost Recovery - 2018 [Member] | PUCO [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets																																20			20
Duke Energy Kentucky [Member] | Duke Energy Kentucky Gas Base Rate Case [Member] | KPSC [Member]
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount												$ 11
Requested rate increase, percentage												11.10%
Approved rate increase (decrease), amount								$ 7
Requested rate increase (decrease), amended amount												$ (5)
Approved return on equity percentage								9.70%
Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Operation, maintenance and other																																188	197		377	378
Loss before income taxes																																(128)	(132)		(273)	(267)
Public utilities, property, plant and equipment, net																																10,727			$ 10,727						10,529
Duke Energy Indiana [Member] | 2019 Indiana Rate Case [Member] | IURC [Member]
Public Utilities, General Disclosures [Line Items]
Rate base																																									10,200
Duke Energy Indiana [Member] | FERC Transmission Rates [Member] | FERC [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage																																			12.38%
Approved return on equity percentage adder																										0.50%
Duke Energy Indiana [Member] | FERC Complaint [Member] | FERC [Member]
Public Utilities, General Disclosures [Line Items]
Requested return on equity, percent																																			8.67%
Duke Energy Indiana [Member] | FERC Complaint 1 [Member] | FERC [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage																									10.32%
Duke Energy Indiana [Member] | FERC Complaint 2 [Member] | FERC [Member]
Public Utilities, General Disclosures [Line Items]
Requested return on equity, percent																								9.70%
Piedmont Natural Gas [Member]
Public Utilities, General Disclosures [Line Items]
Operation, maintenance and other																																83	85		$ 163	167
Loss before income taxes																																9	$ 11		(147)	$ (134)
Public utilities, property, plant and equipment, net																																6,346			6,346						5,911
Piedmont Natural Gas [Member] | North Carolina Integrity Management Rider Filing [Member] | NCUC [Member]
Public Utilities, General Disclosures [Line Items]
Approved rate increase (decrease), amount			$ 9
Piedmont Natural Gas [Member] | Tennessee Integrity Management Rider Filing November 2018 [Member] | TPUC [Member]
Public Utilities, General Disclosures [Line Items]
Approved rate increase (decrease), amount																												$ 3
Piedmont Natural Gas [Member] | North Carolina Rate Case 2019 [Member] | NCUC [Member]
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount						$ 83
Requested rate increase, percentage						9.00%
State and Local Jurisdiction [Member] | North Carolina Department of Revenue [Member] | Duke Energy Carolinas [Member] | South Carolina Rate Case 2018 [Member] | PSCSC [Member]
Public Utilities, General Disclosures [Line Items]
State and local taxes, increase (reduction), amount				$ (17)						$ (17)
State and Local Jurisdiction [Member] | North Carolina Department of Revenue [Member] | Duke Energy Progress [Member] | South Carolina Rate Case 2018 [Member] | PSCSC [Member]
Public Utilities, General Disclosures [Line Items]
State and local taxes, increase (reduction), amount				$ 12						$ 12
Subsequent Event [Member] | Duke Energy Ohio [Member] | MGP Cost Recovery - 2018 [Member] | PUCO [Member] | MGP Costs - Regulatory Disallowance [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets																																						$ 11
Subsequent Event [Member] | Duke Energy Indiana [Member] | 2019 Indiana Rate Case [Member] | IURC [Member]
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount	$ 395
Requested rate increase, percentage	15.00%
Noncurrent Assets, Other [Member] | Duke Energy Florida [Member] | Hurricane Michael Storm Damage [Member]
Public Utilities, General Disclosures [Line Items]
Estimated storm costs - capital and operation maintenance																																$ 225			$ 225						$ 165

Regulatory Matters (Schedule of

Regulatory Matters (Schedule of Net Carrying Value Of Facilities and Megawatt Capacity) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2019USD ($)MW	Dec. 31, 2018USD ($)
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	$ 97,198	$ 91,694
Duke Energy Carolinas [Member]
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	31,202	29,245
Duke Energy Florida [Member]
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	14,388	13,824
Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Public utilities, property, plant and equipment, net	$ 10,727	$ 10,529
Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	5,002
Public utilities, property, plant and equipment, net	$ 3,217
Allen Steam Station Units 1-3 [Member] | Generation Facilities To Be Retired [Member] | Duke Energy Carolinas [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	585
Public utilities, property, plant and equipment, net	$ 156
Gallagher Units 2 and 4 [Member] | Generation Facilities To Be Retired [Member] | Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	280
Public utilities, property, plant and equipment, net	$ 118
Gibson Units 1-5 [Member] | Generation Facilities To Be Retired [Member] | Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	3,132
Public utilities, property, plant and equipment, net	$ 1,960
Cayuga Units 1-2 [Member] | Generation Facilities To Be Retired [Member] | Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	1,005
Public utilities, property, plant and equipment, net	$ 983

Commitments and Contingencies_2

Commitments and Contingencies (Narrative) (Details) $ in Millions	Jun. 18, 2018USD ($)	Jun. 30, 2019USD ($)plantclaim	Dec. 31, 2018USD ($)	Dec. 31, 2016plant
Valuation and Qualifying Accounts [Abstract]
Loss contingency accrual		$ 64	$ 65
Coal Ash Insurance Coverage Litigation [Member]
Valuation and Qualifying Accounts [Abstract]
Number of NC and SC plants with ash basins | plant		15
NCDEQ State Enforcement Actions [Member]
Valuation and Qualifying Accounts [Abstract]
Number of plants with no disputed facts | plant				7
Number of NC plants with ash basins | plant				14
Number of plants with disputed facts | plant				7
Duke Energy Carolinas [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency accrual		$ 7	9
Duke Energy Carolinas [Member] | Asbestos-related Injuries and Damages Claims [Member]
Valuation and Qualifying Accounts [Abstract]
Asbestos-related injuries and damages reserves		607	630
Reinsurance retention policy, excess retention, amount reinsured		764
Probable insurance recoveries		$ 739	739
Duke Energy Carolinas [Member] | Asbestos-related Injuries and Damages Claims [Member] | Non-Malignant Asbestos Claim [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, pending claims, number | claim		145
Asbestos-related injuries and damages reserves		$ 38
Duke Energy Carolinas [Member] | Asbestos-related Injuries and Damages Claims [Member] | Malignant Asbestos Claim [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, pending claims, number | claim		50
Asbestos-related injuries and damages reserves		$ 16
Progress Energy [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency accrual		55	54
Duke Energy Progress [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency accrual		14	12
Duke Energy Progress [Member] | Spent Nuclear Fuel Matters [Member]
Valuation and Qualifying Accounts [Abstract]
Pending litigation, damages sought	$ 100
Duke Energy Florida [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency accrual		24	$ 24
Duke Energy Florida [Member] | Spent Nuclear Fuel Matters [Member]
Valuation and Qualifying Accounts [Abstract]
Pending litigation, damages sought	$ 203
Duke Energy Florida [Member] | Fluor Contract Litigation [Member]
Valuation and Qualifying Accounts [Abstract]
Pending litigation, damages sought		110
Fluor Letter Of Credit [Member] | Duke Energy Florida [Member]
Valuation and Qualifying Accounts [Abstract]
Drawings on credit facility		$ 67

Commitments and Contingencies_3

Commitments and Contingencies (Schedule of Environmental Loss Contingencies) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at beginning of period	$ 77	$ 81
Provisions/adjustments	9	1
Cash reductions	(22)	(14)
Balance at end of period	64	68
Environmental exit costs, reasonably possible additional loss	51
Duke Energy Carolinas [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at beginning of period	11	10
Provisions/adjustments	4	2
Cash reductions	(3)	(1)
Balance at end of period	12	11
Environmental exit costs, reasonably possible additional loss	12
Progress Energy [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at beginning of period	11	15
Provisions/adjustments	3	2
Cash reductions	(1)	(2)
Balance at end of period	13	15
Duke Energy Progress [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at beginning of period	4	3
Provisions/adjustments	2	2
Cash reductions	(1)	(1)
Balance at end of period	5	4
Duke Energy Florida [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at beginning of period	6	12
Provisions/adjustments	1	(1)
Cash reductions	0	(1)
Balance at end of period	7	10
Duke Energy Ohio [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at beginning of period	48	47
Provisions/adjustments	2	(3)
Cash reductions	(18)	(9)
Balance at end of period	32	35
Environmental exit costs, reasonably possible additional loss	29
Duke Energy Indiana [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at beginning of period	5	5
Provisions/adjustments		1
Cash reductions	0	(1)
Balance at end of period	5	5
Piedmont Natural Gas [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at beginning of period	2	2
Cash reductions	0
Balance at end of period	2	$ 2
Environmental exit costs, reasonably possible additional loss	$ 2

Commitments and Contingencies_4

Commitments and Contingencies (Schedule of Legal Reserves) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Loss Contingencies [Line Items]
Reserves for legal matters	$ 64	$ 65
Duke Energy Carolinas [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	7	9
Progress Energy [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	55	54
Duke Energy Progress [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	14	12
Duke Energy Florida [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	24	24
Piedmont Natural Gas [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	$ 1	$ 1

Leases (Operating Lease Right-o

Leases (Operating Lease Right-of-use Assets and Liabilities) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Jan. 01, 2019
Lessee, Lease, Description [Line Items]
ROU assets	$ 1,735	$ 1,750
Operating lease liabilities – current	213	205
Operating lease liabilities – noncurrent	1,502	1,504
Duke Energy Carolinas [Member]
Lessee, Lease, Description [Line Items]
ROU assets	141	153
Operating lease liabilities – current	27	28
Operating lease liabilities – noncurrent	117	127
Progress Energy [Member]
Lessee, Lease, Description [Line Items]
ROU assets	839	863
Operating lease liabilities – current	100	96
Operating lease liabilities – noncurrent	747	766
Duke Energy Progress [Member]
Lessee, Lease, Description [Line Items]
ROU assets	407	407
Operating lease liabilities – current	36	35
Operating lease liabilities – noncurrent	377	371
Duke Energy Florida [Member]
Lessee, Lease, Description [Line Items]
ROU assets	432	456
Operating lease liabilities – current	64	61
Operating lease liabilities – noncurrent	370	395
Duke Energy Ohio [Member]
Lessee, Lease, Description [Line Items]
ROU assets	22	23
Operating lease liabilities – current	1	1
Operating lease liabilities – noncurrent	21	22
Duke Energy Indiana [Member]
Lessee, Lease, Description [Line Items]
ROU assets	60	61
Operating lease liabilities – current	4	4
Operating lease liabilities – noncurrent	56	58
Piedmont Natural Gas [Member]
Lessee, Lease, Description [Line Items]
ROU assets	26	26
Operating lease liabilities – current	4	4
Operating lease liabilities – noncurrent	$ 25	$ 25

Leases (Lease Costs) (Details)

Leases (Lease Costs) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Lessee, Lease, Description [Line Items]
Operating cash flows from operating leases		$ 136
Operating lease expense	$ 73	145
Short-term lease expense	6	13
Variable lease expense	10	21
Finance lease expense
Amortization of leased assets	29	56
Interest on lease liabilities	20	37
Total finance lease expense	49	93
Total lease expense	138	272
Operating cash flows from finance leases		37
Financing cash flows from finance leases		56
Finance		175
Operating		78
Duke Energy Carolinas [Member]
Lessee, Lease, Description [Line Items]
Operating cash flows from operating leases		15
Operating lease expense	11	23
Short-term lease expense	2	4
Variable lease expense	4	12
Finance lease expense
Amortization of leased assets	1	2
Interest on lease liabilities	3	7
Total finance lease expense	4	9
Total lease expense	21	48
Operating cash flows from finance leases		7
Financing cash flows from finance leases		2
Operating		2
Progress Energy [Member]
Lessee, Lease, Description [Line Items]
Operating cash flows from operating leases		60
Operating lease expense	40	82
Short-term lease expense	4	7
Variable lease expense	5	7
Finance lease expense
Amortization of leased assets	5	8
Interest on lease liabilities	13	19
Total finance lease expense	18	27
Total lease expense	67	123
Operating cash flows from finance leases		19
Financing cash flows from finance leases		8
Finance		175
Operating		30
Duke Energy Progress [Member]
Lessee, Lease, Description [Line Items]
Operating cash flows from operating leases		23
Operating lease expense	17	36
Short-term lease expense	2	3
Variable lease expense	2	3
Finance lease expense
Amortization of leased assets	1	2
Interest on lease liabilities	10	14
Total finance lease expense	11	16
Total lease expense	32	58
Operating cash flows from finance leases		14
Financing cash flows from finance leases		2
Finance		175
Operating		30
Duke Energy Florida [Member]
Lessee, Lease, Description [Line Items]
Operating cash flows from operating leases		37
Operating lease expense	23	46
Short-term lease expense	2	4
Variable lease expense	3	4
Finance lease expense
Amortization of leased assets	4	6
Interest on lease liabilities	3	5
Total finance lease expense	7	11
Total lease expense	35	65
Operating cash flows from finance leases		5
Financing cash flows from finance leases		6
Duke Energy Ohio [Member]
Lessee, Lease, Description [Line Items]
Operating cash flows from operating leases		1
Operating lease expense	3	6
Short-term lease expense	1	1
Finance lease expense
Amortization of leased assets	1	1
Total finance lease expense	1	1
Total lease expense	5	8
Financing cash flows from finance leases		1
Duke Energy Indiana [Member]
Lessee, Lease, Description [Line Items]
Operating cash flows from operating leases		3
Operating lease expense	5	10
Short-term lease expense		1
Finance lease expense
Interest on lease liabilities	1	1
Total finance lease expense	1	1
Total lease expense	6	12
Operating cash flows from finance leases		1
Piedmont Natural Gas [Member]
Lessee, Lease, Description [Line Items]
Operating cash flows from operating leases		5
Operating lease expense	2	3
Finance lease expense
Total lease expense	$ 2	3
Operating		$ 1

Leases (Rent Expense) (Details)

Leases (Rent Expense) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Operating Leased Assets [Line Items]
Rent expense	$ 268
Duke Energy Carolinas [Member]
Operating Leased Assets [Line Items]
Rent expense	49
Progress Energy [Member]
Operating Leased Assets [Line Items]
Rent expense	143
Duke Energy Progress [Member]
Operating Leased Assets [Line Items]
Rent expense	75
Duke Energy Florida [Member]
Operating Leased Assets [Line Items]
Rent expense	68
Duke Energy Ohio [Member]
Operating Leased Assets [Line Items]
Rent expense	13
Duke Energy Indiana [Member]
Operating Leased Assets [Line Items]
Rent expense	21
Piedmont Natural Gas [Member]
Operating Leased Assets [Line Items]
Rent expense	$ 11

Leases (Operating Lease Maturit

Leases (Operating Lease Maturities) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Operating Lease Liabilities, Payments Due (Topic 842)
2020	$ 279
2021	239
2022	199
2023	190
2024	178
Thereafter	1,055
Total operating lease payments	2,140
Less: present value discount	(425)
Total operating lease liabilities	1,715
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity (Topic 840)
2019		$ 239
2020		219
2021		186
2022		170
2023		160
Thereafter		1,017
Total		1,991
Duke Energy Carolinas [Member]
Operating Lease Liabilities, Payments Due (Topic 842)
2020	33
2021	28
2022	19
2023	18
2024	15
Thereafter	61
Total operating lease payments	174
Less: present value discount	(30)
Total operating lease liabilities	144
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity (Topic 840)
2019		33
2020		29
2021		19
2022		19
2023		17
Thereafter		68
Total		185
Progress Energy [Member]
Operating Lease Liabilities, Payments Due (Topic 842)
2020	129
2021	112
2022	94
2023	95
2024	96
Thereafter	513
Total operating lease payments	1,039
Less: present value discount	(192)
Total operating lease liabilities	847
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity (Topic 840)
2019		97
2020		90
2021		79
2022		76
2023		77
Thereafter		455
Total		874
Duke Energy Progress [Member]
Operating Lease Liabilities, Payments Due (Topic 842)
2020	51
2021	52
2022	40
2023	40
2024	41
Thereafter	306
Total operating lease payments	530
Less: present value discount	(117)
Total operating lease liabilities	413
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity (Topic 840)
2019		49
2020		46
2021		37
2022		34
2023		35
Thereafter		314
Total		515
Duke Energy Florida [Member]
Operating Lease Liabilities, Payments Due (Topic 842)
2020	78
2021	60
2022	54
2023	55
2024	55
Thereafter	207
Total operating lease payments	509
Less: present value discount	(75)
Total operating lease liabilities	434
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity (Topic 840)
2019		48
2020		44
2021		42
2022		42
2023		42
Thereafter		141
Total		359
Duke Energy Ohio [Member]
Operating Lease Liabilities, Payments Due (Topic 842)
2020	2
2021	2
2022	2
2023	2
2024	2
Thereafter	22
Total operating lease payments	32
Less: present value discount	(10)
Total operating lease liabilities	22
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity (Topic 840)
2019		2
2020		2
2021		2
2022		2
2023		2
Thereafter		23
Total		33
Duke Energy Indiana [Member]
Operating Lease Liabilities, Payments Due (Topic 842)
2020	6
2021	5
2022	4
2023	4
2024	4
Thereafter	65
Total operating lease payments	88
Less: present value discount	(28)
Total operating lease liabilities	60
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity (Topic 840)
2019		6
2020		5
2021		4
2022		4
2023		5
Thereafter		66
Total		90
Piedmont Natural Gas [Member]
Operating Lease Liabilities, Payments Due (Topic 842)
2020	5
2021	5
2022	5
2023	5
2024	5
Thereafter	7
Total operating lease payments	32
Less: present value discount	(3)
Total operating lease liabilities	$ 29
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity (Topic 840)
2019		5
2020		5
2021		5
2022		5
2023		6
Thereafter		11
Total		$ 37

Leases (Finance Lease Maturitie

Leases (Finance Lease Maturities) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Finance Lease Liabilities, Payments, Due (Topic 842)
2020	$ 177
2021	183
2022	180
2023	171
2024	172
Thereafter	847
Total finance lease payments	1,730
Less: amounts representing interest	(708)
Total finance lease liabilities	1,022
Finance Lease Liabilities, Payments Due (Topic 840)
2019		$ 170
2020		174
2021		177
2022		165
2023		165
Thereafter		577
Minimum annual payments		1,428
Less: amount representing interest		(487)
Total		941
Duke Energy Carolinas [Member]
Finance Lease Liabilities, Payments, Due (Topic 842)
2020	19
2021	17
2022	14
2023	14
2024	14
Thereafter	191
Total finance lease payments	269
Less: amounts representing interest	(162)
Total finance lease liabilities	107
Finance Lease Liabilities, Payments Due (Topic 840)
2019		20
2020		20
2021		15
2022		15
2023		15
Thereafter		204
Minimum annual payments		289
Less: amount representing interest		(180)
Total		109
Progress Energy [Member]
Finance Lease Liabilities, Payments, Due (Topic 842)
2020	69
2021	69
2022	69
2023	69
2024	64
Thereafter	560
Total finance lease payments	900
Less: amounts representing interest	(483)
Total finance lease liabilities	417
Finance Lease Liabilities, Payments Due (Topic 840)
2019		45
2020		46
2021		45
2022		45
2023		45
Thereafter		230
Minimum annual payments		456
Less: amount representing interest		(205)
Total		251
Duke Energy Progress [Member]
Finance Lease Liabilities, Payments, Due (Topic 842)
2020	44
2021	44
2022	44
2023	44
2024	44
Thereafter	547
Total finance lease payments	767
Less: amounts representing interest	(457)
Total finance lease liabilities	310
Finance Lease Liabilities, Payments Due (Topic 840)
2019		20
2020		21
2021		20
2022		21
2023		21
Thereafter		209
Minimum annual payments		312
Less: amount representing interest		(175)
Total		137
Duke Energy Florida [Member]
Finance Lease Liabilities, Payments, Due (Topic 842)
2020	25
2021	25
2022	25
2023	25
2024	20
Thereafter	13
Total finance lease payments	133
Less: amounts representing interest	(26)
Total finance lease liabilities	107
Finance Lease Liabilities, Payments Due (Topic 840)
2019		25
2020		25
2021		25
2022		24
2023		24
Thereafter		21
Minimum annual payments		144
Less: amount representing interest		(30)
Total		114
Duke Energy Ohio [Member]
Finance Lease Liabilities, Payments Due (Topic 840)
2019		2
Minimum annual payments		2
Total		2
Duke Energy Indiana [Member]
Finance Lease Liabilities, Payments, Due (Topic 842)
2020	1
2021	1
2022	1
2023	1
2024	1
Thereafter	28
Total finance lease payments	33
Less: amounts representing interest	(23)
Total finance lease liabilities	$ 10
Finance Lease Liabilities, Payments Due (Topic 840)
2019		1
2020		1
2021		1
2022		1
2023		1
Thereafter		27
Minimum annual payments		32
Less: amount representing interest		(22)
Total		$ 10

Leases (Supplemental Financial

Leases (Supplemental Financial Information) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jan. 01, 2019
Assets
Operating	$ 1,735	$ 1,750
Finance	1,013
Total lease assets	2,748
Current
Operating	213	205
Finance	115
Noncurrent
Operating	1,502	1,504
Finance	907
Total lease liabilities	2,737
Cash paid for amounts included in the measurement of lease liabilities(a)
Operating cash flows from operating leases	136
Operating cash flows from finance leases	37
Financing cash flows from finance leases	56
Lease assets obtained in exchange for new lease liabilities (non-cash)
Operating	78
Finance	$ 175
Weighted-average remaining lease term (years)
Operating leases	11 years
Finance leases	16 years
Weighted-average discount rate
Operating leases	3.90%
Finance leases	7.90%
Duke Energy Carolinas [Member]
Assets
Operating	$ 141	153
Finance	122
Total lease assets	263
Current
Operating	27	28
Finance	6
Noncurrent
Operating	117	127
Finance	101
Total lease liabilities	251
Cash paid for amounts included in the measurement of lease liabilities(a)
Operating cash flows from operating leases	15
Operating cash flows from finance leases	7
Financing cash flows from finance leases	2
Lease assets obtained in exchange for new lease liabilities (non-cash)
Operating	$ 2
Weighted-average remaining lease term (years)
Operating leases	9 years
Finance leases	19 years
Weighted-average discount rate
Operating leases	3.70%
Finance leases	12.90%
Progress Energy [Member]
Assets
Operating	$ 839	863
Finance	423
Total lease assets	1,262
Current
Operating	100	96
Finance	23
Noncurrent
Operating	747	766
Finance	394
Total lease liabilities	1,264
Cash paid for amounts included in the measurement of lease liabilities(a)
Operating cash flows from operating leases	60
Operating cash flows from finance leases	19
Financing cash flows from finance leases	8
Lease assets obtained in exchange for new lease liabilities (non-cash)
Operating	30
Finance	$ 175
Weighted-average remaining lease term (years)
Operating leases	10 years
Finance leases	17 years
Weighted-average discount rate
Operating leases	3.80%
Finance leases	11.80%
Duke Energy Progress [Member]
Assets
Operating	$ 407	407
Finance	309
Total lease assets	716
Current
Operating	36	35
Finance	6
Noncurrent
Operating	377	371
Finance	304
Total lease liabilities	723
Cash paid for amounts included in the measurement of lease liabilities(a)
Operating cash flows from operating leases	23
Operating cash flows from finance leases	14
Financing cash flows from finance leases	2
Lease assets obtained in exchange for new lease liabilities (non-cash)
Operating	30
Finance	$ 175
Weighted-average remaining lease term (years)
Operating leases	12 years
Finance leases	18 years
Weighted-average discount rate
Operating leases	3.80%
Finance leases	12.40%
Duke Energy Florida [Member]
Assets
Operating	$ 432	456
Finance	114
Total lease assets	546
Current
Operating	64	61
Finance	17
Noncurrent
Operating	370	395
Finance	90
Total lease liabilities	541
Cash paid for amounts included in the measurement of lease liabilities(a)
Operating cash flows from operating leases	37
Operating cash flows from finance leases	5
Financing cash flows from finance leases	$ 6
Weighted-average remaining lease term (years)
Operating leases	9 years
Finance leases	12 years
Weighted-average discount rate
Operating leases	3.70%
Finance leases	8.30%
Duke Energy Ohio [Member]
Assets
Operating	$ 22	23
Total lease assets	22
Current
Operating	1	1
Finance	0
Noncurrent
Operating	21	22
Total lease liabilities	22
Cash paid for amounts included in the measurement of lease liabilities(a)
Operating cash flows from operating leases	1
Financing cash flows from finance leases	$ 1
Weighted-average remaining lease term (years)
Operating leases	18 years
Finance leases	0 years
Weighted-average discount rate
Operating leases	4.20%
Finance leases	0.00%
Duke Energy Indiana [Member]
Assets
Operating	$ 60	61
Finance	10
Total lease assets	70
Current
Operating	4	4
Noncurrent
Operating	56	58
Finance	10
Total lease liabilities	70
Cash paid for amounts included in the measurement of lease liabilities(a)
Operating cash flows from operating leases	3
Operating cash flows from finance leases	$ 1
Weighted-average remaining lease term (years)
Operating leases	19 years
Finance leases	27 years
Weighted-average discount rate
Operating leases	4.10%
Finance leases	11.90%
Piedmont Natural Gas [Member]
Assets
Operating	$ 26	26
Total lease assets	26
Current
Operating	4	4
Noncurrent
Operating	25	$ 25
Total lease liabilities	29
Cash paid for amounts included in the measurement of lease liabilities(a)
Operating cash flows from operating leases	5
Lease assets obtained in exchange for new lease liabilities (non-cash)
Operating	$ 1
Weighted-average remaining lease term (years)
Operating leases	6 years
Finance leases	0 years
Weighted-average discount rate
Operating leases	3.60%

Leases (Narrative) (Details)

Leases (Narrative) (Details) - Renewable Energy Projects [Member] $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019USD ($)	Jun. 30, 2019USD ($)
Lessee, Lease, Description [Line Items]
Contingent lease payments	$ 72	$ 136
Operating lease assets, cost basis	3,344	3,344
Operating lease assets, accumulated depreciation	$ 661	$ 661

Debt and Credit Facilities (Nar

Debt and Credit Facilities (Narrative) (Details) - USD ($)	1 Months Ended
	May 31, 2019	Jun. 30, 2019
Debt Instrument [Line Items]
Debt issuances		$ 3,800,000,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility size		8,000,000,000
Duke Energy Carolinas [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility size		1,750,000,000
Duke Energy Carolinas [Member] | USDOJ [Member] | North Carolina Ash Basins [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Minimum master credit facility balance required		250,000,000
Duke Energy Progress [Member]
Debt Instrument [Line Items]
Debt issuances		600,000,000
Duke Energy Progress [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility size		1,250,000,000
Piedmont Natural Gas [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	$ 600,000,000
Debt issuances		600,000,000
Piedmont Natural Gas [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility size		500,000,000
Unsecured Debentures, June 2019 Issuance [Member] | Duke Energy Kentucky [Member]
Debt Instrument [Line Items]
Debt issuances		210,000,000
Unsecured Debentures, 3.23% Issuance [Member] | Duke Energy Kentucky [Member]
Debt Instrument [Line Items]
Debt issuances		$ 95,000,000
Interest rate		3.23%
Unsecured Debentures, 3.56% Issuance [Member] | Duke Energy Kentucky [Member]
Debt Instrument [Line Items]
Debt issuances		$ 75,000,000
Interest rate		3.56%
Unsecured Debentures, 4.32% Issuance [Member] | Duke Energy Kentucky [Member]
Debt Instrument [Line Items]
Debt issuances		$ 40,000,000
Interest rate		4.32%
Debt Maturing October 2019, 4.650% Coupon [Member] | Duke Energy Kentucky [Member]
Debt Instrument [Line Items]
Debt issuances		$ 100,000,000
Interest rate		4.65%
Term Loan [Member] | Piedmont Natural Gas [Member]
Debt Instrument [Line Items]
Repayments of Debt	$ 350,000,000

Debt and Credit Facilities (Sum

Debt and Credit Facilities (Summary of Debt Issuances) (Details) - USD ($)	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Debt Instrument [Line Items]
Debt issuances	$ 3,800,000,000
Repayments of long-term debt	2,155,000,000	$ 2,190,000,000
Parent Company [Member]
Debt Instrument [Line Items]
Debt issuances	1,800,000,000
Duke Energy Carolinas [Member]
Debt Instrument [Line Items]
Repayments of long-term debt	3,000,000	702,000,000
Duke Energy Progress [Member]
Debt Instrument [Line Items]
Debt issuances	600,000,000
Repayments of long-term debt	602,000,000
Duke Energy Florida [Member]
Debt Instrument [Line Items]
Repayments of long-term debt	136,000,000	635,000,000
Duke Energy Ohio [Member]
Debt Instrument [Line Items]
Debt issuances	800,000,000
Repayments of long-term debt	451,000,000	$ 3,000,000
Duke Energy Ohio [Member] | April 2019 First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Repayments of long-term debt	450,000,000
Piedmont Natural Gas [Member]
Debt Instrument [Line Items]
Debt issuances	600,000,000
Repayments of long-term debt	350,000,000
Piedmont Natural Gas [Member] | Senior Unsecured Term Loan Facility Due September 2019 [Member]
Debt Instrument [Line Items]
Repayments of long-term debt	350,000,000
Unsecured Debt [Member] | March 2019 Debt Issuance 3.250% Coupon Due 2022 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 300,000,000
Interest rate	3.251%
Unsecured Debt [Member] | March 2019 Debt Issuance 3.227% Coupon Due 2022 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 300,000,000
Interest rate	3.227%
Unsecured Debt [Member] | May 2019 Debt Issuance 3.500% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 600,000,000
Interest rate	3.50%
Unsecured Debt [Member] | June 2019 Debt Issuance 3.400% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 600,000,000
Interest rate	3.40%
Unsecured Debt [Member] | June 2019 Debt Issuance 4.200% Coupon Due 2049 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 600,000,000
Interest rate	4.20%
Unsecured Debt [Member] | Parent Company [Member] | March 2019 Debt Issuance 3.250% Coupon Due 2022 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 300,000,000
Unsecured Debt [Member] | Parent Company [Member] | March 2019 Debt Issuance 3.227% Coupon Due 2022 [Member]
Debt Instrument [Line Items]
Debt issuances	300,000,000
Unsecured Debt [Member] | Parent Company [Member] | May 2019 Debt Issuance 3.500% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	0
Unsecured Debt [Member] | Piedmont Natural Gas [Member] | May 2019 Debt Issuance 3.500% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	600,000,000
First Mortgage [Member] | January 2019 Debt Issuance 3.650% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 400,000,000
Interest rate	3.65%
First Mortgage [Member] | January 2019 Debt Issuance 4.300% Coupon Due 2049 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 400,000,000
Interest rate	4.30%
First Mortgage [Member] | March 2019 Debt Issuance 3.450% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 600,000,000
Interest rate	3.45%
First Mortgage [Member] | Duke Energy Progress [Member] | March 2019 Debt Issuance 3.450% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 600,000,000
First Mortgage [Member] | Duke Energy Ohio [Member] | January 2019 Debt Issuance 3.650% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	400,000,000
First Mortgage [Member] | Duke Energy Ohio [Member] | January 2019 Debt Issuance 4.300% Coupon Due 2049 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 400,000,000

Debt and Credit Facilities (S_2

Debt and Credit Facilities (Summary of Current Maturities of Long-term Debt) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 2,698	$ 3,406
Other debt obligations [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 468
Parent Company [Member] | Unsecured Debt [Member] | Debt Maturing September 2019, 5.050% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	5.05%
Current maturities of long-term debt	$ 500
Parent Company [Member] | Unsecured Debt [Member] | Debt Maturing June 2020, 2.100% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	2.10%
Current maturities of long-term debt	$ 330
Piedmont Natural Gas [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt		350
Duke Energy Kentucky [Member] | Debt Maturing October 2019, 4.650% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	4.65%
Duke Energy Kentucky [Member] | Secured Debt [Member] | Debt Maturing October 2019, 4.650% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	4.65%
Current maturities of long-term debt	$ 100
Progress Energy [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 1,026	1,672
Progress Energy [Member] | Secured Debt [Member] | Debt Maturing December 2019, 4.875% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	4.875%
Current maturities of long-term debt	$ 350
Duke Energy Florida [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 671	270
Duke Energy Florida [Member] | First Mortgage Bonds [Member] | Bonds Maturing January 2020, 1.850% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	1.85%
Current maturities of long-term debt	$ 250
Duke Energy Florida [Member] | First Mortgage Bonds [Member] | Bonds Maturing April 2020, 4.550% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	4.55%
Current maturities of long-term debt	$ 250
Duke Energy Carolinas [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 456	$ 6
Duke Energy Carolinas [Member] | First Mortgage Bonds [Member] | Bonds Maturing June 2020, 4.300% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	4.30%
Current maturities of long-term debt	$ 450

Debt and Credit Facilities (Sch

Debt and Credit Facilities (Schedule of Line of Credit Facilities) (Details) - Revolving Credit Facility [Member]	Jun. 30, 2019USD ($)
Line of Credit Facility [Line Items]
Facility size	$ 8,000,000,000
Commercial paper	(3,420,000,000)
Outstanding letters of credit	(53,000,000)
Tax exempt bonds	(81,000,000)
Coal ash set-aside	(500,000,000)
Available capacity	3,946,000,000
Parent Company [Member]
Line of Credit Facility [Line Items]
Facility size	2,650,000,000
Commercial paper	(1,009,000,000)
Outstanding letters of credit	(45,000,000)
Available capacity	1,596,000,000
Duke Energy Carolinas [Member]
Line of Credit Facility [Line Items]
Facility size	1,750,000,000
Commercial paper	(1,099,000,000)
Outstanding letters of credit	(4,000,000)
Coal ash set-aside	(250,000,000)
Available capacity	397,000,000
Duke Energy Progress [Member]
Line of Credit Facility [Line Items]
Facility size	1,250,000,000
Commercial paper	(276,000,000)
Outstanding letters of credit	(2,000,000)
Coal ash set-aside	(250,000,000)
Available capacity	722,000,000
Duke Energy Florida [Member]
Line of Credit Facility [Line Items]
Facility size	800,000,000
Commercial paper	(474,000,000)
Available capacity	326,000,000
Duke Energy Ohio [Member]
Line of Credit Facility [Line Items]
Facility size	450,000,000
Commercial paper	(236,000,000)
Available capacity	214,000,000
Duke Energy Indiana [Member]
Line of Credit Facility [Line Items]
Facility size	600,000,000
Commercial paper	(326,000,000)
Tax exempt bonds	(81,000,000)
Available capacity	193,000,000
Piedmont Natural Gas [Member]
Line of Credit Facility [Line Items]
Facility size	500,000,000
Outstanding letters of credit	(2,000,000)
Available capacity	498,000,000
Proceeds Loaned To Subsidiary Registrants [Member] | Parent Company [Member]
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) - USD ($)	2 Months Ended	6 Months Ended
	Feb. 28, 2019	Jun. 30, 2019
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility size		$ 8,000,000,000
Duke Energy Progress [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility size		1,250,000,000
Duke Energy Progress [Member] | Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Facility size		700,000,000
Amount drawn		700,000,000
Drawings on credit facility	$ 650,000,000
Piedmont Natural Gas [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility size		$ 500,000,000
Duke Energy (Parent) Three-Year Revolving Credit Facility [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility Term		3 years
Facility size		$ 1,000,000,000
Amount drawn		$ 500,000,000

Asset Retirement Obligations (A

Asset Retirement Obligations (ARO by Category) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Asset Retirement Obligations [Line Items]
Total ARO	$ 12,628	$ 10,467
Less: current portion	739	919
Total noncurrent ARO	11,889	9,548
Duke Energy Carolinas [Member]
Asset Retirement Obligations [Line Items]
Total ARO	5,342	3,949
Less: current portion	203	290
Total noncurrent ARO	5,139	3,659
Progress Energy [Member]
Asset Retirement Obligations [Line Items]
Total ARO	6,193	5,411
Less: current portion	416	514
Total noncurrent ARO	5,777	4,897
Duke Energy Progress [Member]
Asset Retirement Obligations [Line Items]
Total ARO	5,616	4,820
Less: current portion	413	509
Total noncurrent ARO	5,203	4,311
Duke Energy Florida [Member]
Asset Retirement Obligations [Line Items]
Total ARO	577	591
Less: current portion	3	5
Total noncurrent ARO	574	586
Duke Energy Ohio [Member]
Asset Retirement Obligations [Line Items]
Total ARO	89	93
Less: current portion	6	6
Total noncurrent ARO	83	87
Duke Energy Indiana [Member]
Asset Retirement Obligations [Line Items]
Total ARO	719	722
Less: current portion	115	109
Total noncurrent ARO	604	613
Piedmont Natural Gas [Member]
Asset Retirement Obligations [Line Items]
Total ARO	19	19
Total noncurrent ARO	19	$ 19
Decommissioning of Nuclear Power Facilities [Member]
Asset Retirement Obligations [Line Items]
Total ARO	5,807
Decommissioning of Nuclear Power Facilities [Member] | Duke Energy Carolinas [Member]
Asset Retirement Obligations [Line Items]
Total ARO	2,401
Decommissioning of Nuclear Power Facilities [Member] | Progress Energy [Member]
Asset Retirement Obligations [Line Items]
Total ARO	3,265
Decommissioning of Nuclear Power Facilities [Member] | Duke Energy Progress [Member]
Asset Retirement Obligations [Line Items]
Total ARO	2,739
Decommissioning of Nuclear Power Facilities [Member] | Duke Energy Florida [Member]
Asset Retirement Obligations [Line Items]
Total ARO	526
Closure of Ash Impoundments [Member]
Asset Retirement Obligations [Line Items]
Total ARO	6,498
Closure of Ash Impoundments [Member] | Duke Energy Carolinas [Member]
Asset Retirement Obligations [Line Items]
Total ARO	2,894
Closure of Ash Impoundments [Member] | Progress Energy [Member]
Asset Retirement Obligations [Line Items]
Total ARO	2,858
Closure of Ash Impoundments [Member] | Duke Energy Progress [Member]
Asset Retirement Obligations [Line Items]
Total ARO	2,839
Closure of Ash Impoundments [Member] | Duke Energy Florida [Member]
Asset Retirement Obligations [Line Items]
Total ARO	19
Closure of Ash Impoundments [Member] | Duke Energy Ohio [Member]
Asset Retirement Obligations [Line Items]
Total ARO	47
Closure of Ash Impoundments [Member] | Duke Energy Indiana [Member]
Asset Retirement Obligations [Line Items]
Total ARO	699
Other [Member]
Asset Retirement Obligations [Line Items]
Total ARO	323
Other [Member] | Duke Energy Carolinas [Member]
Asset Retirement Obligations [Line Items]
Total ARO	47
Other [Member] | Progress Energy [Member]
Asset Retirement Obligations [Line Items]
Total ARO	70
Other [Member] | Duke Energy Progress [Member]
Asset Retirement Obligations [Line Items]
Total ARO	38
Other [Member] | Duke Energy Florida [Member]
Asset Retirement Obligations [Line Items]
Total ARO	32
Other [Member] | Duke Energy Ohio [Member]
Asset Retirement Obligations [Line Items]
Total ARO	42
Other [Member] | Duke Energy Indiana [Member]
Asset Retirement Obligations [Line Items]
Total ARO	20
Other [Member] | Piedmont Natural Gas [Member]
Asset Retirement Obligations [Line Items]
Total ARO	$ 19

Asset Retirement Obligations _2

Asset Retirement Obligations (ARO Rollforward) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2019USD ($)
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of period	$ 10,467
Accretion expense	245
Liabilities settled	(404)
Revision in estimates of cash flows	2,320
Balance at end of period	12,628
Duke Energy Carolinas [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of period	3,949
Accretion expense	111
Liabilities settled	(155)
Revision in estimates of cash flows	1,437
Balance at end of period	5,342
Progress Energy [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of period	5,411
Accretion expense	124
Liabilities settled	(225)
Revision in estimates of cash flows	883
Balance at end of period	6,193
Duke Energy Progress [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of period	4,820
Accretion expense	111
Liabilities settled	(197)
Revision in estimates of cash flows	882
Balance at end of period	5,616
Duke Energy Florida [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of period	591
Accretion expense	13
Liabilities settled	(28)
Revision in estimates of cash flows	1
Balance at end of period	577
Duke Energy Ohio [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of period	93
Accretion expense	2
Liabilities settled	(6)
Balance at end of period	89
Duke Energy Indiana [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of period	722
Accretion expense	14
Liabilities settled	(17)
Balance at end of period	719
Piedmont Natural Gas [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of period	19
Balance at end of period	$ 19

Asset Retirement Obligations (N

Asset Retirement Obligations (NDTF Information) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Asset Retirement Obligations [Line Items]
Legally restricted NDTF investments, fair value	$ 6,327	$ 5,579
Duke Energy Carolinas [Member]
Asset Retirement Obligations [Line Items]
Legally restricted NDTF investments, fair value	3,574	3,133
Duke Energy Progress [Member]
Asset Retirement Obligations [Line Items]
Legally restricted NDTF investments, fair value	2,753	2,446
Progress Energy [Member]
Asset Retirement Obligations [Line Items]
Legally restricted NDTF investments, fair value	$ 2,753	$ 2,446

Goodwill (Rollforward of Goodwi

Goodwill (Rollforward of Goodwill) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Goodwill [Line Items]
Goodwill balance	$ 19,425	$ 19,425
Accumulated impairment charges	(122)	(122)
Goodwill balance, adjusted for accumulated impairment charges	19,303	19,303
Electric Utilities and Infrastructure [Member]
Goodwill [Line Items]
Goodwill balance	17,379	17,379
Goodwill balance, adjusted for accumulated impairment charges	17,379	17,379
Gas Utilities and Infrastructure [Member]
Goodwill [Line Items]
Goodwill balance	1,924	1,924
Goodwill balance, adjusted for accumulated impairment charges	1,924	1,924
Commercial Renewables [Member]
Goodwill [Line Items]
Goodwill balance	122	122
Accumulated impairment charges	$ (122)	$ (122)

Goodwill (Narrative) (Details)

Goodwill (Narrative) (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
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 [Member]
Goodwill [Line Items]
Goodwill	17,379,000,000	17,379,000,000
Gas Utilities and Infrastructure [Member]
Goodwill [Line Items]
Goodwill	1,924,000,000	1,924,000,000
Duke Energy Ohio [Member]
Goodwill [Line Items]
Goodwill	920,000,000	920,000,000
Accumulated impairment charges	216,000,000	216,000,000
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member]
Goodwill [Line Items]
Goodwill	596,000,000	596,000,000
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member]
Goodwill [Line Items]
Goodwill	324,000,000	324,000,000
Progress Energy [Member]
Goodwill [Line Items]
Goodwill	3,655,000,000	3,655,000,000
Accumulated impairment charges	0	0
Piedmont Natural Gas [Member]
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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Duke Energy Carolinas [Member] | Corporate governance and shared service expenses [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$ 197	$ 213	$ 409	$ 433
Duke Energy Carolinas [Member] | Indemnification coverages [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	5	5	10	11
Duke Energy Carolinas [Member] | JDA [Member] | Duke Energy Progress [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	17	19	40	53
Related party transaction, expenses from transactions with related party	20	19	113	73
Duke Energy Carolinas [Member] | Intercompany natural gas transactions [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	3	4	7	8
Progress Energy [Member] | Corporate governance and shared service expenses [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	183	206	359	397
Progress Energy [Member] | Indemnification coverages [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	10	9	19	17
Progress Energy [Member] | JDA [Member] | Duke Energy Carolinas [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	20	19	113	73
Related party transaction, expenses from transactions with related party	17	19	40	53
Progress Energy [Member] | Intercompany natural gas transactions [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	19	19	38	38
Duke Energy Progress [Member] | Corporate governance and shared service expenses [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	108	126	214	244
Duke Energy Progress [Member] | Indemnification coverages [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	4	3	8	6
Duke Energy Progress [Member] | JDA [Member] | Duke Energy Carolinas [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	20	19	113	73
Related party transaction, expenses from transactions with related party	17	19	40	53
Duke Energy Progress [Member] | Intercompany natural gas transactions [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	19	19	38	38
Duke Energy Florida [Member] | Corporate governance and shared service expenses [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	75	80	145	153
Duke Energy Florida [Member] | Indemnification coverages [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	6	6	11	11
Duke Energy Ohio [Member] | Corporate governance and shared service expenses [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	83	90	168	179
Duke Energy Ohio [Member] | Indemnification coverages [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	1	1	2	2
Duke Energy Indiana [Member] | Corporate governance and shared service expenses [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	93	96	190	197
Duke Energy Indiana [Member] | Indemnification coverages [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	1	2	3	4
Piedmont Natural Gas [Member] | Corporate governance and shared service expenses [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	37	40	69	76
Piedmont Natural Gas [Member] | Indemnification coverages [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party			1	1
Piedmont Natural Gas [Member] | Intercompany natural gas transactions [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	22	23	45	46
Piedmont Natural Gas [Member] | Natural gas storage and transportation costs [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$ 6	$ 6	$ 11	$ 12

Related Party Transactions (Int

Related Party Transactions (Intercompany Income Taxes) (Details) - Affiliated Entity [Member] - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Duke Energy Carolinas [Member]
Related Party Transaction [Line Items]
Income taxes receivable		$ 52
Income tax payable	$ 76
Progress Energy [Member]
Related Party Transaction [Line Items]
Income taxes receivable	25	47
Duke Energy Progress [Member]
Related Party Transaction [Line Items]
Income taxes receivable		29
Income tax payable	41
Duke Energy Florida [Member]
Related Party Transaction [Line Items]
Income tax payable	19	16
Duke Energy Ohio [Member]
Related Party Transaction [Line Items]
Income taxes receivable	15
Income tax payable		3
Duke Energy Indiana [Member]
Related Party Transaction [Line Items]
Income taxes receivable		8
Income tax payable	1
Piedmont Natural Gas [Member]
Related Party Transaction [Line Items]
Income taxes receivable	$ 26
Income tax payable		$ 45

Derivatives and Hedging (Notion

Derivatives and Hedging (Notional Amounts of Derivative Instruments) (Details) Mcf in Millions, $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2019USD ($)GWhMcf	Dec. 31, 2018USD ($)GWhMcf
Commodity Contracts [Member] | Electricity [Member]
Derivative [Line Items]
Notional amount, energy measure (in gigawatt-hours) | GWh	33,135	15,286
Commodity Contracts [Member] | Natural Gas [Member]
Derivative [Line Items]
Notional amount, volume (in millions of decatherms) | Mcf	740	739
Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 2,386	$ 2,644
Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	959	923
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	1,427	1,721
Variable Interest Entity, Primary Beneficiary [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	659	422
Variable Interest Entity, Primary Beneficiary [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 194	$ 194
Duke Energy Carolinas [Member] | Commodity Contracts [Member] | Natural Gas [Member]
Derivative [Line Items]
Notional amount, volume (in millions of decatherms) | Mcf	133	121
Duke Energy Carolinas [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 600	$ 300
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 600	$ 300
Progress Energy [Member] | Commodity Contracts [Member] | Natural Gas [Member]
Derivative [Line Items]
Notional amount, volume (in millions of decatherms) | Mcf	173	169
Progress Energy [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 800	$ 1,200
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 800	$ 1,200
Duke Energy Progress [Member] | Commodity Contracts [Member] | Natural Gas [Member]
Derivative [Line Items]
Notional amount, volume (in millions of decatherms) | Mcf	173	166
Duke Energy Progress [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 250	$ 650
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	250	$ 650
Duke Energy Florida [Member] | Commodity Contracts [Member] | Natural Gas [Member]
Derivative [Line Items]
Notional amount, volume (in millions of decatherms) | Mcf		3
Duke Energy Florida [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	550	$ 550
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 550	$ 550
Duke Energy Ohio [Member] | Commodity Contracts [Member] | Electricity [Member]
Derivative [Line Items]
Notional amount, energy measure (in gigawatt-hours) | GWh	3,514	1,786
Duke Energy Ohio [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 27	$ 27
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 27	$ 27
Duke Energy Indiana [Member] | Commodity Contracts [Member] | Electricity [Member]
Derivative [Line Items]
Notional amount, energy measure (in gigawatt-hours) | GWh	29,621	13,500
Duke Energy Indiana [Member] | Commodity Contracts [Member] | Natural Gas [Member]
Derivative [Line Items]
Notional amount, volume (in millions of decatherms) | Mcf	4	1
Piedmont Natural Gas [Member] | Commodity Contracts [Member] | Natural Gas [Member]
Derivative [Line Items]
Notional amount, volume (in millions of decatherms) | Mcf	430	448

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	Jun. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	$ 38	$ 57
Location and fair value amounts of derivatives (Liability)	342	242
Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	37	38
Noncurrent Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	19
Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	154	68
Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	188	174
Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	37	39
Location and fair value amounts of derivatives (Liability)	204	191
Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	18
Location and fair value amounts of derivatives (Liability)	138	51
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		1
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Noncurrent Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	3
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	4	12
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	32	6
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	37	35
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Noncurrent Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		4
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	64	33
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	140	158
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Noncurrent Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		12
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	86	23
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	16	10
Duke Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		3
Location and fair value amounts of derivatives (Liability)	93	33
Duke Energy Carolinas [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Duke Energy Carolinas [Member] | Noncurrent Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		1
Duke Energy Carolinas [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	85	23
Duke Energy Carolinas [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	8	10
Duke Energy Carolinas [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		3
Location and fair value amounts of derivatives (Liability)	39	24
Duke Energy Carolinas [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	54	9
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Noncurrent Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		1
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	31	14
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	8	10
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	54	9
Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		4
Location and fair value amounts of derivatives (Liability)	90	44
Progress Energy [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Progress Energy [Member] | Noncurrent Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Progress Energy [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	55	23
Progress Energy [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	35	21
Progress Energy [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		4
Location and fair value amounts of derivatives (Liability)	48	25
Progress Energy [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	42	19
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Noncurrent Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	24	10
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	24	15
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	31	13
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	11	6
Duke Energy Progress [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		4
Location and fair value amounts of derivatives (Liability)	35	27
Duke Energy Progress [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Duke Energy Progress [Member] | Noncurrent Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Duke Energy Progress [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	26	16
Duke Energy Progress [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	9	11
Duke Energy Progress [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		4
Location and fair value amounts of derivatives (Liability)	33	11
Duke Energy Progress [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	2	16
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Noncurrent Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	24	5
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	9	6
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	2	11
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		5
Duke Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	39	9
Duke Energy Florida [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	29	8
Duke Energy Florida [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	10	1
Duke Energy Florida [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		6
Duke Energy Florida [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	39	3
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		6
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	29	2
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	10	1
Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	6
Location and fair value amounts of derivatives (Liability)	6	5
Duke Energy Ohio [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	6
Duke Energy Ohio [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	1
Duke Energy Ohio [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	5	4
Duke Energy Ohio [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	6
Duke Energy Ohio [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	6	5
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	6
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	1
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	5	4
Duke Energy Indiana [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	29	23
Location and fair value amounts of derivatives (Liability)	2
Duke Energy Indiana [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	29	23
Duke Energy Indiana [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	2
Duke Energy Indiana [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	29	23
Location and fair value amounts of derivatives (Liability)	2
Duke Energy Indiana [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	29	23
Duke Energy Indiana [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	2
Piedmont Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	3
Location and fair value amounts of derivatives (Liability)	114	141
Piedmont Natural Gas [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	3
Piedmont Natural Gas [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	7	8
Piedmont Natural Gas [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	107	133
Piedmont Natural Gas [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	3
Location and fair value amounts of derivatives (Liability)	114	141
Piedmont Natural Gas [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	3
Piedmont Natural Gas [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	7	8
Piedmont Natural Gas [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	$ 107	$ 133

Derivatives and Hedging (Schedu

Derivatives and Hedging (Schedule of Offsetting Assets) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	$ 38	$ 57
Net amounts recognized on the Condensed Consolidated Balance Sheet	38	57
Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	37	38
Gross amounts offset		(3)
Net amounts recognized on the Condensed Consolidated Balance Sheet	37	35
Noncurrent Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	1	19
Gross amounts offset		(3)
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	16
Duke Energy Carolinas [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized		3
Net amounts recognized on the Condensed Consolidated Balance Sheet		3
Duke Energy Carolinas [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized		2
Gross amounts offset		(2)
Duke Energy Carolinas [Member] | Noncurrent Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized		1
Gross amounts offset		(1)
Progress Energy [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized		4
Net amounts recognized on the Condensed Consolidated Balance Sheet		4
Progress Energy [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized		2
Gross amounts offset		(2)
Progress Energy [Member] | Noncurrent Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized		2
Gross amounts offset		(2)
Duke Energy Progress [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized		4
Net amounts recognized on the Condensed Consolidated Balance Sheet		4
Duke Energy Progress [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized		2
Gross amounts offset		(2)
Duke Energy Progress [Member] | Noncurrent Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized		2
Gross amounts offset		(2)
Duke Energy Ohio [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	7	6
Duke Energy Ohio [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	7	6
Net amounts recognized on the Condensed Consolidated Balance Sheet	7	6
Duke Energy Indiana [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	29	23
Net amounts recognized on the Condensed Consolidated Balance Sheet	29	23
Duke Energy Indiana [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	29	23
Net amounts recognized on the Condensed Consolidated Balance Sheet	29	23
Piedmont Natural Gas [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	2	3
Net amounts recognized on the Condensed Consolidated Balance Sheet	2	3
Piedmont Natural Gas [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	2	3
Net amounts recognized on the Condensed Consolidated Balance Sheet	$ 2	$ 3

Derivatives and Hedging (Sche_2

Derivatives and Hedging (Schedule of Offsetting Liabilities) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	$ 342	$ 242
Net amounts recognized on the Condensed Consolidated Balance Sheet	342	242
Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	154	68
Gross amounts offset	(1)	(4)
Net amounts recognized on the Condensed Consolidated Balance Sheet	153	64
Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	188	174
Gross amounts offset		(3)
Net amounts recognized on the Condensed Consolidated Balance Sheet	188	171
Duke Energy Carolinas [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	93	33
Net amounts recognized on the Condensed Consolidated Balance Sheet	93	33
Duke Energy Carolinas [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	85	23
Gross amounts offset		(2)
Net amounts recognized on the Condensed Consolidated Balance Sheet	85	21
Duke Energy Carolinas [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	8	10
Gross amounts offset		(1)
Net amounts recognized on the Condensed Consolidated Balance Sheet	8	9
Progress Energy [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	90	44
Net amounts recognized on the Condensed Consolidated Balance Sheet	90	44
Progress Energy [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	55	23
Gross amounts offset	(1)	(2)
Net amounts recognized on the Condensed Consolidated Balance Sheet	54	21
Progress Energy [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	35	21
Gross amounts offset		(2)
Net amounts recognized on the Condensed Consolidated Balance Sheet	35	19
Duke Energy Progress [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	35	27
Net amounts recognized on the Condensed Consolidated Balance Sheet	35	27
Duke Energy Progress [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	26	16
Gross amounts offset	(1)	(2)
Net amounts recognized on the Condensed Consolidated Balance Sheet	25	14
Duke Energy Progress [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	9	11
Gross amounts offset		(2)
Net amounts recognized on the Condensed Consolidated Balance Sheet	9	9
Duke Energy Florida [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	39	9
Net amounts recognized on the Condensed Consolidated Balance Sheet	39	9
Duke Energy Florida [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	29	8
Net amounts recognized on the Condensed Consolidated Balance Sheet	29	8
Duke Energy Florida [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	10	1
Net amounts recognized on the Condensed Consolidated Balance Sheet	10	1
Duke Energy Ohio [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	6	5
Duke Energy Ohio [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	1	1
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	1
Duke Energy Ohio [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	5	4
Net amounts recognized on the Condensed Consolidated Balance Sheet	5	4
Duke Energy Indiana [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	2
Net amounts recognized on the Condensed Consolidated Balance Sheet	2
Duke Energy Indiana [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	2
Net amounts recognized on the Condensed Consolidated Balance Sheet	2
Piedmont Natural Gas [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	114	141
Net amounts recognized on the Condensed Consolidated Balance Sheet	114	141
Piedmont Natural Gas [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	7	8
Net amounts recognized on the Condensed Consolidated Balance Sheet	7	8
Piedmont Natural Gas [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	107	133
Net amounts recognized on the Condensed Consolidated Balance Sheet	$ 107	$ 133

Derivatives and Hedging (Deriva

Derivatives and Hedging (Derivative Instruments with Credit-Risk Related Contingent Features and Cash Collateral) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Schedule of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	$ 67	$ 44
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	67	44
Duke Energy Carolinas [Member]
Schedule of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	34	19
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	34	19
Progress Energy [Member]
Schedule of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	33	25
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	33	25
Duke Energy Progress [Member]
Schedule of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	33	25
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	$ 33	$ 25

Derivatives and Hedging (Narrat

Derivatives and Hedging (Narrative) (Details)	Jun. 30, 2019shares
Call Option [Member]
Derivative [Line Items]
Aggregate notional amount	305,000
Put Option [Member]
Derivative [Line Items]
Aggregate notional amount	305,000

Investments in Debt and Equit_3

Investments in Debt and Equity Securities (All Debt and Equity Securities Through OCI and FV-NI - ASU 2016-01) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	$ 3,209	$ 2,458
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	40	131
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	8,030	7,075
Debt securities, available-for-sale	2,577
Ndtf [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Equity Securities, FV-NI, Accumulated Unrealized Gain	3,076	2,402
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	3,153	2,421
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	39	126
Cash and cash equivalents	114	88
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	7,603	6,706
Equity Securities, FV-NI, Accumulated Unrealized Loss	36	95
Equity securities, FV-NI	5,178	4,475
Debt securities, available-for-sale	2,425	2,231
Other Classification [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Equity Securities, FV-NI, Accumulated Unrealized Gain	49	36
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	56	37
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	1	5
Cash and cash equivalents	49	22
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	427	369
Equity Securities, FV-NI, Accumulated Unrealized Loss		1
Equity securities, FV-NI	112	99
Debt securities, available-for-sale	315	270
Duke Energy Carolinas [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt securities, available-for-sale	1,120
Duke Energy Carolinas [Member] | Ndtf [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Equity Securities, FV-NI, Accumulated Unrealized Gain	1,671	1,309
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	1,711	1,316
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	12	74
Cash and cash equivalents	41	29
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	4,044	3,553
Equity Securities, FV-NI, Accumulated Unrealized Loss	9	54
Equity securities, FV-NI	2,883	2,484
Debt securities, available-for-sale	1,161	1,069
Progress Energy [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	1,445	1,105
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	27	52
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	3,656	3,217
Debt securities, available-for-sale	1,241
Progress Energy [Member] | Ndtf [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Equity Securities, FV-NI, Accumulated Unrealized Gain	1,405	1,093
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	1,442	1,105
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	27	52
Cash and cash equivalents	73	59
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	3,559	3,153
Equity Securities, FV-NI, Accumulated Unrealized Loss	27	41
Equity securities, FV-NI	2,295	1,991
Debt securities, available-for-sale	1,264	1,162
Progress Energy [Member] | Other Classification [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	3
Cash and cash equivalents	47	17
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	97	64
Debt securities, available-for-sale	97	64
Duke Energy Progress [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	1,128	842
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	24	39
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	2,836	2,500
Debt securities, available-for-sale	906
Duke Energy Progress [Member] | Ndtf [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Equity Securities, FV-NI, Accumulated Unrealized Gain	1,092	833
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	1,128	842
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	24	39
Cash and cash equivalents	42	46
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	2,834	2,494
Equity Securities, FV-NI, Accumulated Unrealized Loss	24	30
Equity securities, FV-NI	1,886	1,588
Debt securities, available-for-sale	948	906
Duke Energy Progress [Member] | Other Classification [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Cash and cash equivalents	2	6
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	2	6
Debt securities, available-for-sale	2	6
Duke Energy Florida [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	317	263
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	3	13
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	777	707
Debt securities, available-for-sale	335
Duke Energy Florida [Member] | Ndtf [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Equity Securities, FV-NI, Accumulated Unrealized Gain	313	260
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	314	263
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	3	13
Cash and cash equivalents	31	13
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	725	659
Equity Securities, FV-NI, Accumulated Unrealized Loss	3	11
Equity securities, FV-NI	409	403
Debt securities, available-for-sale	316	256
Duke Energy Florida [Member] | Other Classification [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	3
Cash and cash equivalents	2	1
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	52	48
Debt securities, available-for-sale	52	48
Duke Energy Indiana [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Equity Securities, FV-NI, Accumulated Unrealized Gain	37	29
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	37	29
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	1	1
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	116	108
Equity securities, FV-NI	74	67
Debt securities, available-for-sale	42
Duke Energy Indiana [Member] | Other Classification [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Equity securities, FV-NI	$ 74	$ 67

Investments in Debt and Equit_4

Investments in Debt and Equity Securities (Equity Securities, FV-NI - ASU 2016-01) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Equity Securities, FV-NI, Realized Gain (Loss) [Abstract]
Equity securities, FV-NI, realized gain	$ 66	$ 47	$ 101	$ 66
Equity securities, FV-NI, realized loss	63	31	93	44
Ndtf [Member]
Equity Securities, FV-NI, Accumulated Unrealized Gain (Loss) [Abstract]
Equity Securities, FV-NI, Accumulated Unrealized Gain	3,076		3,076		$ 2,402
Equity Securities, FV-NI, Accumulated Unrealized Loss	36		36		95
Equity securities, FV-NI	5,178		5,178		4,475
Other Classification [Member]
Equity Securities, FV-NI, Accumulated Unrealized Gain (Loss) [Abstract]
Equity Securities, FV-NI, Accumulated Unrealized Gain	49		49		36
Equity Securities, FV-NI, Accumulated Unrealized Loss					1
Equity securities, FV-NI	112		112		99
Duke Energy Carolinas [Member]
Equity Securities, FV-NI, Realized Gain (Loss) [Abstract]
Equity securities, FV-NI, realized gain	44	26	67	36
Equity securities, FV-NI, realized loss	48	17	69	22
Duke Energy Carolinas [Member] | Ndtf [Member]
Equity Securities, FV-NI, Accumulated Unrealized Gain (Loss) [Abstract]
Equity Securities, FV-NI, Accumulated Unrealized Gain	1,671		1,671		1,309
Equity Securities, FV-NI, Accumulated Unrealized Loss	9		9		54
Equity securities, FV-NI	2,883		2,883		2,484
Progress Energy [Member]
Equity Securities, FV-NI, Realized Gain (Loss) [Abstract]
Equity securities, FV-NI, realized gain	22	21	34	30
Equity securities, FV-NI, realized loss	15	14	24	22
Progress Energy [Member] | Ndtf [Member]
Equity Securities, FV-NI, Accumulated Unrealized Gain (Loss) [Abstract]
Equity Securities, FV-NI, Accumulated Unrealized Gain	1,405		1,405		1,093
Equity Securities, FV-NI, Accumulated Unrealized Loss	27		27		41
Equity securities, FV-NI	2,295		2,295		1,991
Duke Energy Progress [Member]
Equity Securities, FV-NI, Realized Gain (Loss) [Abstract]
Equity securities, FV-NI, realized gain	7	17	17	25
Equity securities, FV-NI, realized loss	7	12	15	20
Duke Energy Progress [Member] | Ndtf [Member]
Equity Securities, FV-NI, Accumulated Unrealized Gain (Loss) [Abstract]
Equity Securities, FV-NI, Accumulated Unrealized Gain	1,092		1,092		833
Equity Securities, FV-NI, Accumulated Unrealized Loss	24		24		30
Equity securities, FV-NI	1,886		1,886		1,588
Duke Energy Florida [Member]
Equity Securities, FV-NI, Realized Gain (Loss) [Abstract]
Equity securities, FV-NI, realized gain	15	4	17	5
Equity securities, FV-NI, realized loss	8	$ 2	9	$ 2
Duke Energy Florida [Member] | Ndtf [Member]
Equity Securities, FV-NI, Accumulated Unrealized Gain (Loss) [Abstract]
Equity Securities, FV-NI, Accumulated Unrealized Gain	313		313		260
Equity Securities, FV-NI, Accumulated Unrealized Loss	3		3		11
Equity securities, FV-NI	409		409		403
Duke Energy Indiana [Member]
Equity Securities, FV-NI, Accumulated Unrealized Gain (Loss) [Abstract]
Equity Securities, FV-NI, Accumulated Unrealized Gain	37		37		29
Equity securities, FV-NI	74		74		67
Duke Energy Indiana [Member] | Other Classification [Member]
Equity Securities, FV-NI, Accumulated Unrealized Gain (Loss) [Abstract]
Equity securities, FV-NI	$ 74		$ 74		$ 67

Investments in Debt Securities

Investments in Debt Securities and Equity Securities (Available-for-sale, OCI - ASU 2016-01) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale	$ 2,577		$ 2,577
Debt Securities, Available-for-sale, Realized Gain (Loss) [Abstract]
Debt securities, available-for-sale, realized gain	47	$ 5	57	$ 10
Debt securities, available-for-sale, realized loss	36	12	47	25
Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale	2,425		2,425		$ 2,231
Other Classification [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale	315		315		270
Corporate debt securities [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	30		30		4
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	1		1		13
Debt securities, available-for-sale	571		571		566
Corporate debt securities [Member] | Other Classification [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	2		2
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					2
Debt securities, available-for-sale	60		60		60
Municipal bonds [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	10		10		1
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					4
Debt securities, available-for-sale	318		318		353
Municipal bonds [Member] | Other Classification [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	3		3		0
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	1		1		1
Debt securities, available-for-sale	90		90		85
US treasury and government [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	34		34		14
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	1		1		12
Debt securities, available-for-sale	1,270		1,270		1,076
US treasury and government [Member] | Other Classification [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	2		2		1
Debt securities, available-for-sale	51		51		45
Other debt obligations [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	3		3
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	1		1		2
Debt securities, available-for-sale	152		152		148
Other debt obligations [Member] | Other Classification [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					1
Debt securities, available-for-sale	65		65		58
Duke Energy Carolinas [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale	1,120		1,120
Debt Securities, Available-for-sale, Realized Gain (Loss) [Abstract]
Debt securities, available-for-sale, realized gain	16	4	25	9
Debt securities, available-for-sale, realized loss	11	8	21	18
Duke Energy Carolinas [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale	1,161		1,161		1,069
Duke Energy Carolinas [Member] | Corporate debt securities [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	18		18		2
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	1		1		9
Debt securities, available-for-sale	360		360		341
Duke Energy Carolinas [Member] | Municipal bonds [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	2		2
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					1
Debt securities, available-for-sale	63		63		81
Duke Energy Carolinas [Member] | US treasury and government [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	17		17		5
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	1		1		8
Debt securities, available-for-sale	556		556		475
Duke Energy Carolinas [Member] | Other debt obligations [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	3		3
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	1		1		2
Debt securities, available-for-sale	141		141		143
Progress Energy [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale	1,241		1,241
Debt Securities, Available-for-sale, Realized Gain (Loss) [Abstract]
Debt securities, available-for-sale, realized gain	30	1	31	1
Debt securities, available-for-sale, realized loss	25	4	26	7
Progress Energy [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale	1,264		1,264		1,162
Progress Energy [Member] | Other Classification [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale	97		97		64
Progress Energy [Member] | Corporate debt securities [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	12		12		2
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					4
Debt securities, available-for-sale	211		211		225
Progress Energy [Member] | Municipal bonds [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	8		8		1
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					3
Debt securities, available-for-sale	255		255		272
Progress Energy [Member] | Municipal bonds [Member] | Other Classification [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	3		3
Debt securities, available-for-sale	50		50		47
Progress Energy [Member] | US treasury and government [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	17		17		9
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					4
Debt securities, available-for-sale	714		714		601
Progress Energy [Member] | Other debt obligations [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale	11		11		5
Duke Energy Progress [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale	906		906
Debt Securities, Available-for-sale, Realized Gain (Loss) [Abstract]
Debt securities, available-for-sale, realized gain	1	1	2	1
Debt securities, available-for-sale, realized loss	1	3	2	5
Duke Energy Progress [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale	948		948		906
Duke Energy Progress [Member] | Other Classification [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale	2		2		6
Duke Energy Progress [Member] | Corporate debt securities [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	12		12		2
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					3
Debt securities, available-for-sale	211		211		171
Duke Energy Progress [Member] | Municipal bonds [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	8		8		1
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					3
Debt securities, available-for-sale	255		255		271
Duke Energy Progress [Member] | US treasury and government [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	16		16		6
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					3
Debt securities, available-for-sale	429		429		415
Duke Energy Progress [Member] | Other debt obligations [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale	11		11		3
Duke Energy Florida [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale	335		335
Debt Securities, Available-for-sale, Realized Gain (Loss) [Abstract]
Debt securities, available-for-sale, realized gain	29		29
Debt securities, available-for-sale, realized loss	24	$ 1	24	$ 2
Duke Energy Florida [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale	316		316		256
Duke Energy Florida [Member] | Other Classification [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale	52		52		48
Duke Energy Florida [Member] | Corporate debt securities [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					1
Debt securities, available-for-sale					54
Duke Energy Florida [Member] | Municipal bonds [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale					1
Duke Energy Florida [Member] | Municipal bonds [Member] | Other Classification [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	3		3
Debt securities, available-for-sale	50		50		47
Duke Energy Florida [Member] | US treasury and government [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	1		1		3
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					1
Debt securities, available-for-sale	285		285		186
Duke Energy Florida [Member] | Other debt obligations [Member] | Ndtf [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale					2
Duke Energy Indiana [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale	42		42
Duke Energy Indiana [Member] | Corporate debt securities [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale	7		7		8
Duke Energy Indiana [Member] | Municipal bonds [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	1		1		1
Debt securities, available-for-sale	34		34		$ 33
Duke Energy Indiana [Member] | US treasury and government [Member]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt securities, available-for-sale	$ 1		$ 1

Investments in Debt and Equit_5

Investments in Debt and Equity Securities (Available-For-Sale Investments) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, realized loss	$ 36	$ 12	$ 47	$ 25
Debt securities, available-for-sale, realized gain	47	5	57	10
Equity securities, FV-NI, realized loss	63	31	93	44
Equity securities, FV-NI, realized gain	66	47	101	66
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	3,209		3,209		$ 2,458
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	40		40		131
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	8,030		8,030		7,075
Debt securities, available-for-sale	2,577		2,577
Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	3,153		3,153		2,421
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	39		39		126
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	7,603		7,603		6,706
Debt securities, available-for-sale	2,425		2,425		2,231
Equity Securities, FV-NI, Accumulated Unrealized Gain	3,076		3,076		2,402
Equity Securities, FV-NI, Accumulated Unrealized Loss	36		36		95
Cash and cash equivalents	114		114		88
Equity securities, FV-NI	5,178		5,178		4,475
Other Classification [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	56		56		37
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	1		1		5
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	427		427		369
Debt securities, available-for-sale	315		315		270
Equity Securities, FV-NI, Accumulated Unrealized Gain	49		49		36
Equity Securities, FV-NI, Accumulated Unrealized Loss					1
Cash and cash equivalents	49		49		22
Equity securities, FV-NI	112		112		99
Duke Energy Carolinas [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, realized loss	11	8	21	18
Debt securities, available-for-sale, realized gain	16	4	25	9
Equity securities, FV-NI, realized loss	48	17	69	22
Equity securities, FV-NI, realized gain	44	26	67	36
Debt securities, available-for-sale	1,120		1,120
Duke Energy Carolinas [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	1,711		1,711		1,316
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	12		12		74
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	4,044		4,044		3,553
Debt securities, available-for-sale	1,161		1,161		1,069
Equity Securities, FV-NI, Accumulated Unrealized Gain	1,671		1,671		1,309
Equity Securities, FV-NI, Accumulated Unrealized Loss	9		9		54
Cash and cash equivalents	41		41		29
Equity securities, FV-NI	2,883		2,883		2,484
Progress Energy [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, realized loss	25	4	26	7
Debt securities, available-for-sale, realized gain	30	1	31	1
Equity securities, FV-NI, realized loss	15	14	24	22
Equity securities, FV-NI, realized gain	22	21	34	30
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	1,445		1,445		1,105
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	27		27		52
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	3,656		3,656		3,217
Debt securities, available-for-sale	1,241		1,241
Progress Energy [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	1,442		1,442		1,105
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	27		27		52
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	3,559		3,559		3,153
Debt securities, available-for-sale	1,264		1,264		1,162
Equity Securities, FV-NI, Accumulated Unrealized Gain	1,405		1,405		1,093
Equity Securities, FV-NI, Accumulated Unrealized Loss	27		27		41
Cash and cash equivalents	73		73		59
Equity securities, FV-NI	2,295		2,295		1,991
Progress Energy [Member] | Other Classification [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	3		3
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	97		97		64
Debt securities, available-for-sale	97		97		64
Cash and cash equivalents	47		47		17
Duke Energy Progress [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, realized loss	1	3	2	5
Debt securities, available-for-sale, realized gain	1	1	2	1
Equity securities, FV-NI, realized loss	7	12	15	20
Equity securities, FV-NI, realized gain	7	17	17	25
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	1,128		1,128		842
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	24		24		39
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	2,836		2,836		2,500
Debt securities, available-for-sale	906		906
Duke Energy Progress [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	1,128		1,128		842
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	24		24		39
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	2,834		2,834		2,494
Debt securities, available-for-sale	948		948		906
Equity Securities, FV-NI, Accumulated Unrealized Gain	1,092		1,092		833
Equity Securities, FV-NI, Accumulated Unrealized Loss	24		24		30
Cash and cash equivalents	42		42		46
Equity securities, FV-NI	1,886		1,886		1,588
Duke Energy Progress [Member] | Other Classification [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	2		2		6
Debt securities, available-for-sale	2		2		6
Cash and cash equivalents	2		2		6
Duke Energy Florida [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, realized loss	24	1	24	2
Debt securities, available-for-sale, realized gain	29		29
Equity securities, FV-NI, realized loss	8	2	9	2
Equity securities, FV-NI, realized gain	15	$ 4	17	$ 5
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	317		317		263
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	3		3		13
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	777		777		707
Debt securities, available-for-sale	335		335
Duke Energy Florida [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	314		314		263
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	3		3		13
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	725		725		659
Debt securities, available-for-sale	316		316		256
Equity Securities, FV-NI, Accumulated Unrealized Gain	313		313		260
Equity Securities, FV-NI, Accumulated Unrealized Loss	3		3		11
Cash and cash equivalents	31		31		13
Equity securities, FV-NI	409		409		403
Duke Energy Florida [Member] | Other Classification [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	3		3
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	52		52		48
Debt securities, available-for-sale	52		52		48
Cash and cash equivalents	2		2		1
Duke Energy Indiana [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	37		37		29
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	1		1		1
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	116		116		108
Debt securities, available-for-sale	42		42
Equity Securities, FV-NI, Accumulated Unrealized Gain	37		37		29
Equity securities, FV-NI	74		74		67
Duke Energy Indiana [Member] | Other Classification [Member]
Debt Securities, Available-for-sale [Line Items]
Equity securities, FV-NI	74		74		67
Corporate debt securities [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	30		30		4
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	1		1		13
Debt securities, available-for-sale	571		571		566
Corporate debt securities [Member] | Other Classification [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	2		2
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					2
Debt securities, available-for-sale	60		60		60
Corporate debt securities [Member] | Duke Energy Carolinas [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	18		18		2
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	1		1		9
Debt securities, available-for-sale	360		360		341
Corporate debt securities [Member] | Progress Energy [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	12		12		2
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					4
Debt securities, available-for-sale	211		211		225
Corporate debt securities [Member] | Duke Energy Progress [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	12		12		2
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					3
Debt securities, available-for-sale	211		211		171
Corporate debt securities [Member] | Duke Energy Florida [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					1
Debt securities, available-for-sale					54
Corporate debt securities [Member] | Duke Energy Indiana [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	7		7		8
Municipal bonds [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	10		10		1
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					4
Debt securities, available-for-sale	318		318		353
Municipal bonds [Member] | Other Classification [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	3		3		0
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	1		1		1
Debt securities, available-for-sale	90		90		85
Municipal bonds [Member] | Duke Energy Carolinas [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	2		2
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					1
Debt securities, available-for-sale	63		63		81
Municipal bonds [Member] | Progress Energy [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	8		8		1
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					3
Debt securities, available-for-sale	255		255		272
Municipal bonds [Member] | Progress Energy [Member] | Other Classification [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	3		3
Debt securities, available-for-sale	50		50		47
Municipal bonds [Member] | Duke Energy Progress [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	8		8		1
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					3
Debt securities, available-for-sale	255		255		271
Municipal bonds [Member] | Duke Energy Florida [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale					1
Municipal bonds [Member] | Duke Energy Florida [Member] | Other Classification [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	3		3
Debt securities, available-for-sale	50		50		47
Municipal bonds [Member] | Duke Energy Indiana [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	1		1		1
Debt securities, available-for-sale	34		34		33
US treasury and government [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	34		34		14
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	1		1		12
Debt securities, available-for-sale	1,270		1,270		1,076
US treasury and government [Member] | Other Classification [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	2		2		1
Debt securities, available-for-sale	51		51		45
US treasury and government [Member] | Duke Energy Carolinas [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	17		17		5
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	1		1		8
Debt securities, available-for-sale	556		556		475
US treasury and government [Member] | Progress Energy [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	17		17		9
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					4
Debt securities, available-for-sale	714		714		601
US treasury and government [Member] | Duke Energy Progress [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	16		16		6
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					3
Debt securities, available-for-sale	429		429		415
US treasury and government [Member] | Duke Energy Florida [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	1		1		3
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					1
Debt securities, available-for-sale	285		285		186
US treasury and government [Member] | Duke Energy Indiana [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	1		1
Other debt obligations [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	3		3
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	1		1		2
Debt securities, available-for-sale	152		152		148
Other debt obligations [Member] | Other Classification [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax					1
Debt securities, available-for-sale	65		65		58
Other debt obligations [Member] | Duke Energy Carolinas [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, accumulated gross unrealized gain, before tax	3		3
Debt securities, available-for-sale, accumulated gross unrealized loss, before tax	1		1		2
Debt securities, available-for-sale	141		141		143
Other debt obligations [Member] | Progress Energy [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	11		11		5
Other debt obligations [Member] | Duke Energy Progress [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	$ 11		$ 11		3
Other debt obligations [Member] | Duke Energy Florida [Member] | Ndtf [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale					$ 2

Investments in Debt and Equit_6

Investments in Debt and Equity Securities (Maturities) (Details) $ in Millions	Jun. 30, 2019USD ($)
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	$ 365
Due after one through five years	527
Due after five through 10 years	499
Due after 10 years	1,186
Total	2,577
Duke Energy Carolinas [Member]
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	43
Due after one through five years	213
Due after five through 10 years	242
Due after 10 years	622
Total	1,120
Progress Energy [Member]
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	315
Due after one through five years	265
Due after five through 10 years	203
Due after 10 years	458
Total	1,241
Duke Energy Progress [Member]
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	29
Due after one through five years	257
Due after five through 10 years	192
Due after 10 years	428
Total	906
Duke Energy Florida [Member]
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	286
Due after one through five years	8
Due after five through 10 years	11
Due after 10 years	30
Total	335
Duke Energy Indiana [Member]
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	4
Due after one through five years	15
Due after five through 10 years	4
Due after 10 years	19
Total	$ 42

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value Measurement Amounts for Assets and Liabilities) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	$ 2,577
Derivative assets	38	$ 57
Total assets	8,068	7,132
Derivative liabilities	(342)	(242)
Net assets (liabilities)	7,726	6,890
Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	3	4
Total assets	6,203	5,156
Derivative liabilities	(12)	(11)
Net assets (liabilities)	6,191	5,145
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets		25
Total assets	1,771	1,883
Derivative liabilities	(216)	(90)
Net assets (liabilities)	1,555	1,793
Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	35	28
Total assets	35	28
Derivative liabilities	(114)	(141)
Net assets (liabilities)	(79)	(113)
Fair Value Measured at Net Asset Value Per Share [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	59	65
Net assets (liabilities)	59	65
Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	5,178	4,475
Debt securities, available-for-sale	2,425	2,231
Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	5,119	4,410
Debt securities, available-for-sale	870	576
Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	1,555	1,655
Ndtf [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	59	65
Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	112	99
Debt securities, available-for-sale	315	270
Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	112	99
Debt securities, available-for-sale	99	67
Other Classification [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	216	203
Duke Energy Carolinas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	1,120
Derivative assets		3
Total assets	4,044	3,556
Derivative liabilities	(93)	(33)
Net assets (liabilities)	3,951	3,523
Duke Energy Carolinas [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	3,074	2,568
Net assets (liabilities)	3,074	2,568
Duke Energy Carolinas [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets		3
Total assets	911	923
Derivative liabilities	(93)	(33)
Net assets (liabilities)	818	890
Duke Energy Carolinas [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	59	65
Net assets (liabilities)	59	65
Duke Energy Carolinas [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	2,883	2,484
Debt securities, available-for-sale	1,161	1,069
Duke Energy Carolinas [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	2,824	2,419
Debt securities, available-for-sale	250	149
Duke Energy Carolinas [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	911	920
Duke Energy Carolinas [Member] | Ndtf [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	59	65
Progress Energy [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	1,241
Derivative assets		4
Total assets	3,656	3,221
Derivative liabilities	(90)	(44)
Net assets (liabilities)	3,566	3,177
Progress Energy [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	2,962	2,435
Net assets (liabilities)	2,962	2,435
Progress Energy [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0	4
Total assets	694	786
Derivative liabilities	(90)	(44)
Net assets (liabilities)	604	742
Progress Energy [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	2,295	1,991
Debt securities, available-for-sale	1,264	1,162
Progress Energy [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	2,295	1,991
Debt securities, available-for-sale	620	427
Progress Energy [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	644	735
Progress Energy [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	97	64
Progress Energy [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	47	17
Progress Energy [Member] | Other Classification [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	50	47
Duke Energy Progress [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	906
Derivative assets		4
Total assets	2,836	2,504
Derivative liabilities	(35)	(27)
Net assets (liabilities)	2,801	2,477
Duke Energy Progress [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	2,192	1,888
Net assets (liabilities)	2,192	1,888
Duke Energy Progress [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets		4
Total assets	644	616
Derivative liabilities	(35)	(27)
Net assets (liabilities)	609	589
Duke Energy Progress [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	1,886	1,588
Debt securities, available-for-sale	948	906
Duke Energy Progress [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	1,886	1,588
Debt securities, available-for-sale	304	294
Duke Energy Progress [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	644	612
Duke Energy Progress [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	2	6
Duke Energy Progress [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	2	6
Duke Energy Florida [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	335
Total assets	777	707
Derivative liabilities	(39)	(9)
Net assets (liabilities)	738	698
Duke Energy Florida [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	727	537
Net assets (liabilities)	727	537
Duke Energy Florida [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	50	170
Derivative liabilities	(39)	(9)
Net assets (liabilities)	11	161
Duke Energy Florida [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	409	403
Debt securities, available-for-sale	316	256
Duke Energy Florida [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	409	403
Debt securities, available-for-sale	316	133
Duke Energy Florida [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale		123
Duke Energy Florida [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	52	48
Duke Energy Florida [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	2	1
Duke Energy Florida [Member] | Other Classification [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	50	47
Duke Energy Indiana [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	74	67
Debt securities, available-for-sale	42
Derivative assets	29	23
Total assets	145	131
Derivative liabilities	(2)
Net assets (liabilities)	143	131
Duke Energy Indiana [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	1	1
Total assets	75	68
Derivative liabilities	(2)
Net assets (liabilities)	73	68
Duke Energy Indiana [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	42	41
Net assets (liabilities)	42	41
Duke Energy Indiana [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	28	22
Total assets	28	22
Net assets (liabilities)	28	22
Duke Energy Indiana [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	74	67
Duke Energy Indiana [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	74	67
Piedmont Natural Gas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	2	3
Derivative liabilities	(114)	(141)
Net assets (liabilities)	(112)	(138)
Piedmont Natural Gas [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	2	3
Net assets (liabilities)	2	3
Piedmont Natural Gas [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	(114)	(141)
Net assets (liabilities)	(114)	(141)
Debt Securities [Member] | Duke Energy Indiana [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	42	41
Debt Securities [Member] | Duke Energy Indiana [Member] | Other Classification [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available-for-sale	$ 42	$ 41

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 ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement, transfers between activity levels	$ 0	$ 0	$ 0	$ 0
Derivatives (net)
Balance at beginning of period	(115,000,000)	(124,000,000)	(113,000,000)	(114,000,000)
Purchases, sales, issuances and settlements:
Purchases	38,000,000	56,000,000	38,000,000	56,000,000
Settlements	(11,000,000)	15,000,000	(23,000,000)	(29,000,000)
Total gains (losses) included on the Condensed Consolidated Balance Sheet	9,000,000	(14,000,000)	19,000,000	(10,000,000)
Balance at end of period	(79,000,000)	(97,000,000)	(79,000,000)	(97,000,000)
Duke Energy Indiana [Member]
Derivatives (net)
Balance at beginning of period	5,000,000		22,000,000	27,000,000
Purchases, sales, issuances and settlements:
Purchases	29,000,000	49,000,000	29,000,000	49,000,000
Settlements	(9,000,000)	(14,000,000)	(19,000,000)	(28,000,000)
Total gains (losses) included on the Condensed Consolidated Balance Sheet	3,000,000	2,000,000	(4,000,000)	(4,000,000)
Balance at end of period	28,000,000	44,000,000	28,000,000	44,000,000
Piedmont Natural Gas [Member]
Derivatives (net)
Balance at beginning of period	(121,000,000)	(132,000,000)	(141,000,000)	(142,000,000)
Purchases, sales, issuances and settlements:
Total gains (losses) and settlements	7,000,000	(18,000,000)	27,000,000	(8,000,000)
Balance at end of period	$ (114,000,000)	$ (150,000,000)	$ (114,000,000)	$ (150,000,000)

Fair Value Measurements (Quanti

Fair Value Measurements (Quantitative Level 3 Fair Value Disclosures) (Details) $ in Millions	Jun. 30, 2019USD ($)$ / MWh$ / MMBTU	Mar. 31, 2019USD ($)	Dec. 31, 2018USD ($)$ / MWh$ / MMBTU	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Jun. 30, 2017USD ($)
Fair Value Measurement Inputs and Valuation Techniques
Net derivative asset (liability)	$ (79)	$ (115)	$ (113)	$ (97)	$ (124)	$ (114)
Duke Energy Ohio [Member] | Financial Transmission Rights [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques
Net derivative asset (liability)	$ 7		$ 6
Duke Energy Ohio [Member] | Financial Transmission Rights [Member] | Minimum [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu) | $ / MWh	0.36		1.19
Duke Energy Ohio [Member] | Financial Transmission Rights [Member] | Maximum [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu) | $ / MWh	3.13		4.59
Duke Energy Indiana [Member]
Fair Value Measurement Inputs and Valuation Techniques
Net derivative asset (liability)	$ 28	5	$ 22	44		27	$ 7
Duke Energy Indiana [Member] | Financial Transmission Rights [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques
Net derivative asset (liability)	$ 28		$ 22
Duke Energy Indiana [Member] | Financial Transmission Rights [Member] | Minimum [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu) | $ / MWh	(0.59)		(2.07)
Duke Energy Indiana [Member] | Financial Transmission Rights [Member] | Maximum [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu) | $ / MWh	7.61		8.27
Piedmont Natural Gas [Member]
Fair Value Measurement Inputs and Valuation Techniques
Net derivative asset (liability)	$ (114)	$ (121)	$ (141)	$ (150)	$ (132)	$ (142)
Piedmont Natural Gas [Member] | Derivative Financial Instruments, Liabilities [Member] | Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques
Net derivative asset (liability)	$ (114)		$ (141)
Piedmont Natural Gas [Member] | Derivative Financial Instruments, Liabilities [Member] | Minimum [Member] | Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu) | $ / MMBTU	1.96		1.87
Piedmont Natural Gas [Member] | Derivative Financial Instruments, Liabilities [Member] | Maximum [Member] | Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques
Input measurements (in usd per MWh and usd per MMBtu) | $ / MMBTU	3.21		2.95

Fair Value Measurements (Other

Fair Value Measurements (Other Fair Value Disclosure) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	$ 57,040	$ 54,529
Long-term debt, fair value	60,667	54,534
Piedmont Natural Gas and Progress Energy [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unamortized debt discount (premium), net	1,500	1,600
Duke Energy Carolinas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	10,964	10,939
Long-term debt, fair value	12,300	11,471
Progress Energy [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	19,199	18,911
Long-term debt, fair value	21,408	19,885
Duke Energy Progress [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	9,049	8,204
Long-term debt, fair value	9,707	8,300
Duke Energy Florida [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	7,213	7,321
Long-term debt, fair value	8,173	7,742
Duke Energy Ohio [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	2,509	2,165
Long-term debt, fair value	2,779	2,239
Duke Energy Indiana [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	3,723	3,782
Long-term debt, fair value	4,363	4,158
Piedmont Natural Gas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	2,384	2,138
Long-term debt, fair value	$ 2,576	$ 2,180

Variable Interest Entities (Nar

Variable Interest Entities (Narrative) (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2017
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Variable interest entity, financial or other support, amount	$ 0	$ 0
Cinergy Receivables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
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
Pioneer Transmission [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Variable interest entity ownership interest	50.00%
OVEC [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Variable interest entity ownership interest	9.00%
Atlantic Coast Pipeline [Member] | Financial Guarantee [Member]
Variable Interest Entities [Line Items]
Maximum potential amount of future payments associated with guarantees	$ 790,000,000
Percentage of potential amount of future payments associated with guarantees as percent of outstanding borrowings	47.00%

Variable Interest Entities (Sch

Variable Interest Entities (Schedule of Accounts Receivable Securitizations) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Variable Interest Entities [Line Items]
Long-Term Debt	$ 54,342	$ 51,123
Duke Energy Carolinas [Member]
Variable Interest Entities [Line Items]
Long-Term Debt	10,208	10,633
Duke Energy Progress [Member]
Variable Interest Entities [Line Items]
Long-Term Debt	8,893	7,451
Duke Energy Florida [Member]
Variable Interest Entities [Line Items]
Long-Term Debt	$ 6,542	7,051
Cinergy Receivables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Line of credit facility, expiration date	Dec. 1, 2020
Facility size	$ 350
Long-Term Debt	328	325
Accounts receivable from securitization	$ 484	564
DERF [Member] | Duke Energy Carolinas [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Line of credit facility, expiration date	Dec. 1, 2020
Facility size	$ 475
Long-Term Debt	475	450
Accounts receivable from securitization	$ 671	699
DEPR [Member] | Duke Energy Progress [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Line of credit facility, expiration date	Feb. 1, 2021
Facility size	$ 325
Long-Term Debt	325	300
Accounts receivable from securitization	$ 518	547
DEFR [Member] | Duke Energy Florida [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Line of credit facility, expiration date	Apr. 1, 2021
Facility size	$ 250
Long-Term Debt	250	225
Accounts receivable from securitization	$ 472	$ 357

Variable Interest Entities (S_2

Variable Interest Entities (Schedule of Consolidated VIEs) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory assets, current	$ 1,918	$ 2,005
Other, current assets	1,267	1,049
Regulatory assets, noncurrent	13,393	13,617
Property, plant and equipment, cost	141,363	134,458
Accumulated depreciation and amortization	(44,482)	(43,126)
Other noncurrent assets	2,975	2,935
Current Liabilities: Other	2,020	2,085
Current maturities of long-term debt	2,698	3,406
Long-Term Debt	54,342	51,123
Other Noncurrent Liabilities: Asset Retirement Obligations	11,889	9,548
Other Noncurrent Liabilities: Other	1,583	1,650
Duke Energy Carolinas [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory assets, current	605	520
Other, current assets	17	72
Regulatory assets, noncurrent	3,392	3,457
Property, plant and equipment, cost	47,249	44,741
Accumulated depreciation and amortization	(16,047)	(15,496)
Other noncurrent assets	1,085	1,027
Current Liabilities: Other	499	571
Current maturities of long-term debt	456	6
Long-Term Debt	10,208	10,633
Other Noncurrent Liabilities: Asset Retirement Obligations	5,139	3,659
Other Noncurrent Liabilities: Other	645	671
Duke Energy Progress [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory assets, current	572	703
Other, current assets	34	62
Regulatory assets, noncurrent	4,124	4,111
Property, plant and equipment, cost	33,288	31,459
Accumulated depreciation and amortization	(11,728)	(11,423)
Other noncurrent assets	586	612
Current Liabilities: Other	395	408
Current maturities of long-term debt	6	603
Long-Term Debt	8,893	7,451
Other Noncurrent Liabilities: Asset Retirement Obligations	5,203	4,311
Other Noncurrent Liabilities: Other	91	106
Duke Energy Florida [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory assets, current	452	434
Other, current assets	46	46
Regulatory assets, noncurrent	2,299	2,454
Property, plant and equipment, cost	19,461	18,792
Accumulated depreciation and amortization	(5,073)	(4,968)
Other noncurrent assets	311	311
Current Liabilities: Other	461	406
Current maturities of long-term debt	671	270
Long-Term Debt	6,542	7,051
Other Noncurrent Liabilities: Asset Retirement Obligations	574	586
Other Noncurrent Liabilities: Other	104	93
DEFPF [Member] | Duke Energy Florida [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	8	5
Regulatory assets, current	52	52
Other, current assets	31	39
Regulatory assets, noncurrent	1,019	1,041
Current Liabilities: Other	10	10
Current maturities of long-term debt	54	53
Long-Term Debt	1,082	1,111
DERF [Member] | Duke Energy Carolinas [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	671	699
Long-Term Debt	475	450
DEPR [Member] | Duke Energy Progress [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	518	547
Long-Term Debt	325	300
DEFR [Member] | Duke Energy Florida [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	472	357
Long-Term Debt	250	225
Cinergy Receivables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	484	564
Long-Term Debt	328	325
Commercial Renewables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Other, current assets	109	123
Property, plant and equipment, cost	4,419	4,007
Accumulated depreciation and amortization	(769)	(698)
Other noncurrent assets	289	261
Current maturities of long-term debt	178	174
Long-Term Debt	1,610	1,587
Other Noncurrent Liabilities: Asset Retirement Obligations	108	106
Other Noncurrent Liabilities: Other	$ 222	$ 212

Variable Interest Entities (S_3

Variable Interest Entities (Schedule of Non-Consolidated VIEs) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates	$ 1,715	$ 1,409
Taxes accrued	521	577
Current Liabilities: Other	2,020	2,085
Deferred income taxes	8,532	7,806
Other Noncurrent Liabilities: Other	1,583	1,650
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates	1,305	1,060
Total assets	1,305	1,060
Taxes accrued	(2)	(1)
Current Liabilities: Other	4	4
Deferred income taxes	48	21
Other Noncurrent Liabilities: Other	11	12
Total liabilities	61	36
Net assets	1,244	1,024
Pipeline Investments [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates	1,066	822
Total assets	1,066	822
Taxes accrued	(2)	(1)
Deferred income taxes	48	21
Total liabilities	46	20
Net assets	1,020	802
Commercial Renewables [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates	187	190
Total assets	187	190
Net assets	187	190
Other VIEs [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates	52	48
Total assets	52	48
Current Liabilities: Other	4	4
Other Noncurrent Liabilities: Other	11	12
Total liabilities	15	16
Net assets	37	32
Duke Energy Ohio [Member]
Variable Interest Entities [Line Items]
Receivables from affiliated companies	50	114
Taxes accrued	135	202
Current Liabilities: Other	76	74
Deferred income taxes	872	817
Other Noncurrent Liabilities: Other	94	93
Duke Energy Ohio [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Receivables from affiliated companies	45	93
Total assets	45	93
Net assets	45	93
Duke Energy Indiana [Member]
Variable Interest Entities [Line Items]
Receivables from affiliated companies	83	122
Taxes accrued	25	43
Current Liabilities: Other	120	107
Deferred income taxes	1,084	1,009
Other Noncurrent Liabilities: Other	14	16
Duke Energy Indiana [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Receivables from affiliated companies	81	118
Total assets	81	118
Net assets	$ 81	$ 118

Variable Interest Entities (Pip

Variable Interest Entities (Pipeline Investments) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Variable Interest Entities [Line Items]
Investments in joint ventures	$ 1,715	$ 1,409
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Investments in joint ventures	$ 1,305	1,060
Atlantic Coast Pipeline [Member]
Variable Interest Entities [Line Items]
Ownership percentage	47.00%
Atlantic Coast Pipeline [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Investments in joint ventures	$ 1,041	797
Constitution Pipeline [Member]
Variable Interest Entities [Line Items]
Ownership percentage	24.00%
Constitution Pipeline [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Investments in joint ventures	$ 25	25
Pipeline Investments [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Investments in joint ventures	$ 1,066	$ 822

Variable Interest Entities (Rec

Variable Interest Entities (Receivables Sold) (Details) - Variable Interest Entity, Not Primary Beneficiary [Member] - Cinergy Receivables [Member] - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Duke Energy Ohio [Member]
Variable Interest Entities [Line Items]
Receivables sold	$ 210	$ 269
Less: Retained interests	45	93
Net receivables sold	165	176
Duke Energy Indiana [Member]
Variable Interest Entities [Line Items]
Receivables sold	314	336
Less: Retained interests	81	118
Net receivables sold	$ 233	$ 218

Variable Interest Entities (Sal

Variable Interest Entities (Sales and Cash Flows) (Details) - Variable Interest Entity, Not Primary Beneficiary [Member] - Cinergy Receivables [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Duke Energy Ohio [Member]
Variable Interest Entities [Line Items]
Receivables sold	$ 429	$ 461	$ 1,004	$ 1,028
Loss recognized on sale	3	3	7	6
Cash proceeds from receivables sold	448	465	1,045	1,050
Collection fees received	1	1	1	1
Return received on retained interests	2	1	4	3
Duke Energy Indiana [Member]
Variable Interest Entities [Line Items]
Receivables sold	676	692	1,410	1,386
Loss recognized on sale	4	4	9	7
Cash proceeds from receivables sold	680	686	1,438	1,397
Collection fees received	1	1	1	1
Return received on retained interests	$ 2	$ 2	$ 5	$ 4

Revenue (Remaining Performance

Revenue (Remaining Performance Obligations) (Details) $ in Millions	Jun. 30, 2019USD ($)
Progress Energy [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 63
Revenue, remaining performance obligation, expected timing of satisfaction, period	6 months
Progress Energy [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 121
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Progress Energy [Member] | 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, amount	$ 87
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Progress Energy [Member] | 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, amount	$ 82
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Progress Energy [Member] | 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, amount	$ 39
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Progress Energy [Member] | 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, amount	$ 42
Progress Energy [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	434
Duke Energy Progress [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 4
Revenue, remaining performance obligation, expected timing of satisfaction, period	6 months
Duke Energy Progress [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 9
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Duke Energy Progress [Member] | 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, amount	$ 9
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Duke Energy Progress [Member] | 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, amount	$ 9
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Duke Energy Progress [Member] | 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, amount	$ 9
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Duke Energy Progress [Member] | 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, amount	$ 9
Duke Energy Progress [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	49
Duke Energy Florida [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 59
Revenue, remaining performance obligation, expected timing of satisfaction, period	6 months
Duke Energy Florida [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 112
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Duke Energy Florida [Member] | 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, amount	$ 78
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Duke Energy Florida [Member] | 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, amount	$ 73
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Duke Energy Florida [Member] | 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, amount	$ 30
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Duke Energy Florida [Member] | 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, amount	$ 33
Duke Energy Florida [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	385
Duke Energy Indiana [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 5
Revenue, remaining performance obligation, expected timing of satisfaction, period	6 months
Duke Energy Indiana [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 10
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Duke Energy Indiana [Member] | 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, amount	$ 5
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Duke Energy Indiana [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 20
Piedmont Natural Gas [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	69
Piedmont Natural Gas [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 34
Revenue, remaining performance obligation, expected timing of satisfaction, period	6 months
Piedmont Natural Gas [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 65
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Piedmont Natural Gas [Member] | 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, amount	$ 64
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Piedmont Natural Gas [Member] | 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, amount	$ 61
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Piedmont Natural Gas [Member] | 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, amount	$ 432
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Piedmont Natural Gas [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 725

Revenue (Disaggregation of Reve

Revenue (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 5,695	$ 5,467	$ 11,693	$ 11,394
Revenue from sources other than contracts with customers	178	176	343	384
Total operating revenues	5,873	5,643	12,036	11,778
Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	5,361	5,111	10,582	10,272
Total operating revenues	5,467	5,215	10,788	10,530
Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,304	2,185	4,674	4,535
Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,584	1,481	3,011	2,856
Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	759	736	1,470	1,400
Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	527	515	1,068	1,148
Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	187	194	359	333
Gas Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	282	294	1,013	1,011
Total operating revenues	282	294	1,014	997
Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	146	153	560	566
Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	85	87	291	288
Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	29	31	77	79
Gas Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	22	23	85	78
Commercial Renewables [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	46	47	88	80
Total operating revenues	118	119	224	220
Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6	15	10	31
Total operating revenues	6	15	10	31
Duke Energy Carolinas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,676	1,646	3,395	3,340
Revenue from sources other than contracts with customers	37	26	62	95
Total operating revenues	1,713	1,672	3,457	3,435
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,676	1,646	3,395	3,340
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	679	659	1,439	1,440
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	531	501	1,027	973
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	289	286	555	541
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	109	115	228	234
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	68	85	146	152
Progress Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,674	2,419	5,167	4,945
Revenue from sources other than contracts with customers	70	79	149	129
Total operating revenues	2,744	2,498	5,316	5,074
Progress Energy [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,674	2,419	5,167	4,945
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,243	1,099	2,357	2,211
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	750	678	1,382	1,309
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	231	224	453	432
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	351	322	704	768
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	99	96	271	225
Duke Energy Progress [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,352	1,245	2,795	2,687
Revenue from sources other than contracts with customers	35	46	76	64
Total operating revenues	1,387	1,291	2,871	2,751
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,352	1,245	2,795	2,687
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	496	452	1,032	968
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	339	300	645	599
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	164	159	325	304
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	309	287	624	684
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	44	47	169	132
Duke Energy Florida [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,322	1,175	2,372	2,258
Revenue from sources other than contracts with customers	31	28	67	60
Total operating revenues	1,353	1,203	2,439	2,318
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,322	1,175	2,372	2,258
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	747	648	1,325	1,243
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	411	377	737	710
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	67	66	128	128
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	42	34	80	84
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	55	50	102	93
Duke Energy Ohio [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	429	462	960	969
Revenue from sources other than contracts with customers	4	(3)	4	14
Total operating revenues	433	459	964	983
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	334	349	689	669
Total operating revenues	336	346	691	682
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	159	181	348	361
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	105	110	208	206
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	36	33	69	63
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	9	2	23	2
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	25	23	41	37
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	95	103	271	276
Total operating revenues	97	103	273	277
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	64	66	176	177
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	26	28	75	77
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3	3	10	10
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2	6	10	12
Duke Energy Ohio [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers		10		24
Duke Energy Indiana [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	709	722	1,473	1,436
Revenue from sources other than contracts with customers	5	16	9	33
Total operating revenues	714	738	1,482	1,469
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	709	722	1,473	1,436
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	225	245	531	523
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	197	188	394	366
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	201	192	391	365
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	59	77	113	145
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	27	20	44	37
Piedmont Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	197	205	767	762
Revenue from sources other than contracts with customers	12	10	21	6
Total operating revenues	209	215	788	768
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	197	205	767	762
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	82	87	384	389
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	59	59	216	211
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	24	28	66	69
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Power Generation [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	13	14	26	27
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 19	$ 17	$ 75	$ 66

Revenue (Unbilled Revenues) (De

Revenue (Unbilled Revenues) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	$ 790	$ 896
Duke Energy Carolinas [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	288	313
Progress Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	270	244
Duke Energy Progress [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	148	148
Duke Energy Florida [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	122	96
Duke Energy Ohio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	1	2
Duke Energy Indiana [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	14	23
Piedmont Natural Gas [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	4	73
Cinergy Receivables [Member] | Duke Energy Ohio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	65	86
Cinergy Receivables [Member] | Duke Energy Indiana [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	$ 116	$ 128

Stockholders' Equity (Earnings

Stockholders' Equity (Earnings Per Share Data) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Class of Stock [Line Items]
Income from continuing operations attributable to Duke Energy common stockholders excluding impact of participating securities	$ 819	$ 504	$ 1,718	$ 1,123
Weighted average common shares outstanding – basic (in shares)	728	703	728	702
Equity Forwards (in shares)		1
Weighted average common shares outstanding – diluted (in shares)	728	704	728	702
Earnings per share from continuing operations attributable to Duke Energy common stockholders, Basic and Diluted (in usd per share)	$ 1.12	$ 0.72	$ 2.36	$ 1.60
Potentially dilutive items excluded from the calculation (in shares)	2	2	2	2
Common Stock [Member]
Class of Stock [Line Items]
Dividends declared per common share (in usd per share)	$ 0.928	$ 0.89	$ 1.855	$ 1.78
Depositary Share [Member]
Class of Stock [Line Items]
Dividends declared on preferred stock per depositary share (in usd per share)	$ 0.307		$ 0.307

Stockholders' Equity (Equity Se

Stockholders' Equity (Equity Securities Offering) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	Feb. 20, 2018	Apr. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Forward Contract Indexed to Issuer's Equity [Line Items]
Maximum value of shares to be issued under ATM program	$ 1,000
Proceeds from the issuance of common stock							$ 27	$ 820
Stock issued during period, shares, DRIP							0.9		2.2
Stock issued during period, value, DRIP							$ 80		$ 174
ATM [Member]
Forward Contract Indexed to Issuer's Equity [Line Items]
Shares, Issued				2.6					2.6
Proceeds from the issuance of common stock				$ 195
ATM [Member] | Wells Fargo Bank [Member]
Forward Contract Indexed to Issuer's Equity [Line Items]
Shares offered					1.3	1.6	1.6	1.3
Forward contract indexed to issuer's equity, forward rate per share						$ 86.23
ATM [Member] | JPMorgan Chase [Member]
Forward Contract Indexed to Issuer's Equity [Line Items]
Shares offered		1.1	1.1
Forward contract indexed to issuer's equity, forward rate per share			$ 89.83
ATM [Member] | Citibank [Member]
Forward Contract Indexed to Issuer's Equity [Line Items]
Shares offered					1.3			1.3
Forward contract indexed to issuer's equity, forward rate per share		$ 88.82
Equity Forwards [Member]
Forward Contract Indexed to Issuer's Equity [Line Items]
Shares offered					21.3			21.3
Settlement alternative, shares					21.3			21.3
Shares, Issued				10.6	10.6			10.6	10.6
Proceeds from the issuance of common stock				$ 766	$ 781

Stockholders' Equity (Preferred

Stockholders' Equity (Preferred Stock) (Details) - USD ($) $ / shares in Units, $ in Millions	Mar. 29, 2019	Jun. 30, 2019	Jun. 15, 2024
Class of Stock [Line Items]
Preferred stock, par value (in usd per share)	$ 0.001	$ 0.001
Proceeds from the issuance of preferred stock, net of issuance costs	$ 973	$ 973
Redemption price (in usd per share)		$ 25.50
Series A Preferred Stock [Member]
Class of Stock [Line Items]
Shares issued (in shares)	40,000,000
Price per share (in usd per share)	$ 25
Liquidation preference per share (in usd per share)	$ 25
Cumulative dividend rate per annum	5.75%
Forecast [Member]
Class of Stock [Line Items]
Redemption price (in usd per share)			$ 25

Employee Benefit Plans (Compone

Employee Benefit Plans (Components of Net Periodic Pension Costs) (Details) - Qualified Pension Plan [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 37	$ 45	$ 74	$ 90
Interest cost on projected benefit obligation	82	75	165	150
Expected return on plan assets	(143)	(140)	(286)	(280)
Amortization of actuarial loss (gain)	25	33	49	66
Amortization of prior service (credit) cost	(8)	(8)	(16)	(16)
Net periodic costs	(7)	5	(14)	10
Duke Energy Carolinas [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	12	15	24	30
Interest cost on projected benefit obligation	21	18	41	36
Expected return on plan assets	(37)	(37)	(75)	(74)
Amortization of actuarial loss (gain)	5	7	11	14
Amortization of prior service (credit) cost	(2)	(2)	(4)	(4)
Net periodic costs	(1)	1	(3)	2
Progress Energy [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	10	13	21	26
Interest cost on projected benefit obligation	26	22	52	46
Expected return on plan assets	(45)	(43)	(89)	(88)
Amortization of actuarial loss (gain)	9	11	18	22
Amortization of prior service (credit) cost		(1)	(1)	(2)
Net periodic costs		2	1	4
Duke Energy Progress [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	6	8	12	15
Interest cost on projected benefit obligation	12	10	24	21
Expected return on plan assets	(21)	(21)	(44)	(42)
Amortization of actuarial loss (gain)	3	5	6	10
Amortization of prior service (credit) cost	(1)	(1)	(1)	(1)
Net periodic costs	(1)	1	(3)	3
Duke Energy Florida [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	6	6	10	11
Interest cost on projected benefit obligation	13	12	27	25
Expected return on plan assets	(22)	(23)	(44)	(46)
Amortization of actuarial loss (gain)	6	6	12	12
Amortization of prior service (credit) cost	(1)	(1)	(1)	(1)
Net periodic costs	2		4	1
Duke Energy Ohio [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	1	1	2	2
Interest cost on projected benefit obligation	4	4	9	9
Expected return on plan assets	(6)	(7)	(14)	(14)
Amortization of actuarial loss (gain)		1	1	2
Net periodic costs	(1)	(1)	(2)	(1)
Duke Energy Indiana [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	2	3	4	5
Interest cost on projected benefit obligation	7	6	13	12
Expected return on plan assets	(10)	(11)	(21)	(21)
Amortization of actuarial loss (gain)	1	2	3	4
Amortization of prior service (credit) cost	(1)		(1)
Net periodic costs	(1)		(2)
Piedmont Natural Gas [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	2	2	3	4
Interest cost on projected benefit obligation	3	3	6	6
Expected return on plan assets	(6)	(6)	(11)	(12)
Amortization of actuarial loss (gain)	1	3	3	6
Amortization of prior service (credit) cost	(2)	(3)	(5)	(6)
Net periodic costs	$ (2)	$ (1)	$ (4)	$ (2)

Employee Benefit Plans (Narrati

Employee Benefit Plans (Narrative) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2019USD ($)
Defined Benefit Plan Disclosure [Line Items]
Remeasurement gain recognized	$ 18
Duke Energy RCBP [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.50%
Cash balance interest crediting rate	4.00%
Increase in plan assets	$ 275
Increase in projected benefit obligation	257
Settlement charge	69
Duke Energy Carolinas [Member] | Duke Energy RCBP [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement charge	43
Duke Energy Progress [Member] | Duke Energy RCBP [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement charge	16
Duke Energy Florida [Member] | Duke Energy RCBP [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement charge	3
Duke Energy Indiana [Member] | Duke Energy RCBP [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement charge	3
Duke Energy Ohio [Member] | Duke Energy RCBP [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement charge	1
Piedmont Natural Gas [Member] | Duke Energy RCBP [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement charge	$ 3

Income Taxes (Effective Tax Rat

Income Taxes (Effective Tax Rates) (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
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	15.90%	16.50%	12.60%	19.90%
Duke Energy Carolinas [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	19.70%	21.50%	18.70%	21.80%
Progress Energy [Member]
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	16.70%	17.30%	17.00%	15.40%
Duke Energy Progress [Member]
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	16.30%	20.10%	17.10%	16.80%
Duke Energy Florida [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	19.60%	18.00%	19.50%	17.40%
Duke Energy Ohio [Member]
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%	25.80%	16.50%	16.00%
Duke Energy Indiana [Member]
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	24.20%	25.80%	24.20%	25.80%
Piedmont Natural Gas [Member]
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	22.20%	27.30%	21.80%	23.90%