Condensed Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating Revenues
Regulated electric	$ 5,053	$ 5,457
Nonregulated electric and other	400	377
Regulated natural gas	169	231
Total operating revenues	5,622	6,065
Operating Expenses
Fuel used in electric generation and purchased power – regulated	1,577	1,941
Fuel used in electric generation and purchased power – nonregulated	58	104
Cost of natural gas	60	111
Operation, maintenance and other	1,489	1,426
Depreciation and amortization	814	777
Property and other taxes	297	264
Impairment charges	3
Total operating expenses	4,298	4,623
Gains (Losses) on Sales of Other Assets and Other, net	9	14
Operating Income	1,333	1,456
Other Income and Expenses
Equity in earnings of unconsolidated affiliates	8	13
Other income and expenses, net	79	74
Total other income and expenses	87	87
Interest Expense	511	403
Income From Continuing Operations Before Income Taxes	909	1,140
Income Tax Expense from Continuing Operations	213	364
Income from Continuing Operations	696	776
Income From Discontinued Operations, net of tax	3	91
Net income	699	867
Less: Net Income Attributable to Noncontrolling Interests	5	3
Net Income (Loss) Attributable to Parent	694	864
Other Comprehensive Income (Loss), net of tax
Pension and OPEB adjustments		(5)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(14)	(7)
Reclassification into earnings from cash flow hedges	2	4
Unrealized gains (losses) on available-for-sale securities	4
Other Comprehensive Income, net of tax	41	(133)
Comprehensive Income	740	734
Less: Comprehensive Income Attributable to Noncontrolling Interests	6	(1)
Comprehensive Income Attributable to Parent	$ 734	$ 735
Income from continuing operations attributable to Duke Energy Corporation common stockholders
Basic (usd per share)	$ 1.00	$ 1.09
Diluted (usd per share)	1.00	1.09
Income from discontinued operations attributable to Duke Energy Corporation common stockholders
Basic (usd per share)	0.01	0.13
Diluted (usd per share)	0.01	0.13
Net income attributable to Duke Energy Corporation common stockholders
Basic (usd per share)	1.01	1.22
Diluted (usd per share)	$ 1.01	$ 1.22
Weighted average shares outstanding
Basic (shares)	689	708
Diluted (shares)	689	708
Duke Energy Carolinas [Member]
Operating Revenues
Total operating revenues	$ 1,740	$ 1,901
Operating Expenses
Fuel used in electric generation and purchased power – regulated	421	578
Operation, maintenance and other	512	489
Depreciation and amortization	259	249
Property and other taxes	67	70
Total operating expenses	1,259	1,386
Operating Income	481	515
Other Income and Expenses
Other income and expenses, net	37	42
Interest Expense	107	102
Income From Continuing Operations Before Income Taxes	411	455
Income Tax Expense from Continuing Operations	140	163
Net Income (Loss) Attributable to Parent	271	292
Other Comprehensive Income (Loss), net of tax
Reclassification into earnings from cash flow hedges	1
Other Comprehensive Income, net of tax	1
Comprehensive Income Attributable to Parent	272	292
Progress Energy [Member]
Operating Revenues
Total operating revenues	2,332	2,536
Operating Expenses
Fuel used in electric generation and purchased power – regulated	860	1,032
Operation, maintenance and other	592	565
Depreciation and amortization	290	287
Property and other taxes	119	111
Impairment charges	2
Total operating expenses	1,863	1,995
Gains (Losses) on Sales of Other Assets and Other, net	6	8
Operating Income	475	549
Other Income and Expenses
Other income and expenses, net	20	27
Interest Expense	160	168
Income From Continuing Operations Before Income Taxes	335	408
Income Tax Expense from Continuing Operations	123	144
Income from Continuing Operations	212	264
Income From Discontinued Operations, net of tax		(1)
Net income	212	263
Less: Net Income Attributable to Noncontrolling Interests	3	3
Net Income (Loss) Attributable to Parent	209	260
Other Comprehensive Income (Loss), net of tax
Pension and OPEB adjustments	1	1
Reclassification into earnings from cash flow hedges	1	(2)
Unrealized gains (losses) on available-for-sale securities	1
Other Comprehensive Income, net of tax	3	(1)
Comprehensive Income	215	262
Less: Comprehensive Income Attributable to Noncontrolling Interests	3	3
Comprehensive Income Attributable to Parent	212	259
Duke Energy Progress [Member]
Operating Revenues
Total operating revenues	1,307	1,449
Operating Expenses
Fuel used in electric generation and purchased power – regulated	448	575
Operation, maintenance and other	386	375
Depreciation and amortization	175	152
Property and other taxes	41	32
Total operating expenses	1,050	1,134
Gains (Losses) on Sales of Other Assets and Other, net	1	1
Operating Income	258	316
Other Income and Expenses
Other income and expenses, net	17	20
Interest Expense	63	60
Income From Continuing Operations Before Income Taxes	212	276
Income Tax Expense from Continuing Operations	75	93
Net Income (Loss) Attributable to Parent	137	183
Duke Energy Florida [Member]
Operating Revenues
Total operating revenues	1,024	1,086
Operating Expenses
Fuel used in electric generation and purchased power – regulated	412	457
Operation, maintenance and other	205	188
Depreciation and amortization	114	134
Property and other taxes	78	80
Impairment charges	2
Total operating expenses	811	859
Operating Income	213	227
Other Income and Expenses
Other income and expenses, net	5	6
Interest Expense	41	49
Income From Continuing Operations Before Income Taxes	177	184
Income Tax Expense from Continuing Operations	67	71
Net Income (Loss) Attributable to Parent	110	113
Other Comprehensive Income (Loss), net of tax
Unrealized gains (losses) on available-for-sale securities	1	0
Other Comprehensive Income, net of tax	1
Comprehensive Income Attributable to Parent	111	113
Duke Energy Ohio [Member]
Operating Revenues
Regulated electric	340	339
Nonregulated electric and other	6	14
Regulated natural gas	170	233
Total operating revenues	516	586
Operating Expenses
Fuel used in electric generation and purchased power – regulated	111	115
Fuel used in electric generation and purchased power – nonregulated	10	14
Cost of natural gas	49	97
Operation, maintenance and other	119	128
Depreciation and amortization	61	57
Property and other taxes	71	70
Total operating expenses	421	481
Gains (Losses) on Sales of Other Assets and Other, net	1	6
Operating Income	96	111
Other Income and Expenses
Other income and expenses, net	2	3
Interest Expense	20	20
Income From Continuing Operations Before Income Taxes	78	94
Income Tax Expense from Continuing Operations	21	35
Income from Continuing Operations	57	59
Income From Discontinued Operations, net of tax	2	90
Net income		149
Net Income (Loss) Attributable to Parent	59	149
Duke Energy Indiana [Member]
Operating Revenues
Total operating revenues	714	788
Operating Expenses
Fuel used in electric generation and purchased power – regulated	228	294
Operation, maintenance and other	162	181
Depreciation and amortization	125	104
Property and other taxes	23	(1)
Total operating expenses	538	578
Operating Income	176	210
Other Income and Expenses
Other income and expenses, net	4	5
Interest Expense	44	45
Income From Continuing Operations Before Income Taxes	136	170
Income Tax Expense from Continuing Operations	41	62
Net Income (Loss) Attributable to Parent	95	108
Other Comprehensive Income (Loss), net of tax
Reclassification into earnings from cash flow hedges	(1)	(1)
Other Comprehensive Income, net of tax	(1)	(1)
Comprehensive Income Attributable to Parent	$ 94	$ 107