Condensed Consolidated Statements of Operations and Comprehensive Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Operating Revenues
Regulated electric	$ 5,457	$ 5,550
Nonregulated electric and other	377	491
Regulated natural gas	231	222
Total operating revenues	6,065	6,263
Operating Expenses
Fuel used in electric generation and purchased power – regulated	1,941	2,000
Fuel used in electric generation and purchased power – nonregulated	104	136
Cost of natural gas and other	111	116
Operation, maintenance and other	1,426	1,449
Depreciation and amortization	777	755
Property and other taxes	264	350
Impairment charges	0	96
Total operating expenses	4,623	4,902
Gains on Sales of Other Assets and Other, net	14	1
Operating Income (Loss)	1,456	1,362
Other Income and Expenses
Equity in earnings of unconsolidated affiliates	13	36
Other income and expenses, net	74	95
Total other income and expenses	87	131
Interest Expense	403	404
Income (Loss) From Continuing Operations Before Income Taxes	1,140	1,089
Income Tax Expense (Benefit) from Continuing Operations	364	339
Income (Loss) From Continuing Operations	776	750
Income (Loss) From Discontinued Operations, net of tax	91	(843)
Net income (loss)	867	(93)
Less: Net Income Attributable to Noncontrolling Interests	3	4
Net Income (Loss) Attributable to Parent	864	(97)
Other Comprehensive (Loss) Income, net of tax
Pension and OPEB adjustments	(5)	(1)
Net unrealized gain (loss) on cash flow hedges	(7)
Reclassification into earnings from cash flow hedges	4
Other Comprehensive (Loss) Income, net of tax	(133)	23
Comprehensive Income (Loss)	734	(70)
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	(1)	5
Comprehensive Income Attributable to Parent	735	(75)
Income from continuing operations attributable to Duke Energy Corporation common shareholders
Basic (usd per share)	$ 1.09	$ 1.05
Diluted (usd per share)	$ 1.09	$ 1.05
Income (Loss) from discontinued operations attributable to Duke Energy Corporation common shareholders
Basic (usd per share)	$ 0.13	$ (1.19)
Diluted (usd per share)	$ 0.13	$ (1.19)
Net Income (Loss) attributable to Duke Energy Corporation common shareholders
Basic (usd per share)	$ 1.22	$ (0.14)
Diluted (usd per share)	$ 1.22	$ (0.14)
Weighted-average shares outstanding
Basic (shares)	708	706
Diluted (shares)	708	706
Duke Energy Carolinas [Member]
Operating Revenues
Total operating revenues	1,901	2,000
Operating Expenses
Fuel used in electric generation and purchased power – regulated	578	658
Operation, maintenance and other	489	487
Depreciation and amortization	249	242
Property and other taxes	70	104
Total operating expenses	1,386	1,491
Operating Income (Loss)	515	509
Other Income and Expenses
Other income and expenses, net	42	49
Interest Expense	102	101
Income (Loss) From Continuing Operations Before Income Taxes	455	457
Income Tax Expense (Benefit) from Continuing Operations	163	171
Net Income (Loss) Attributable to Parent	292	286
Other Comprehensive (Loss) Income, net of tax
Reclassification into earnings from cash flow hedges		1
Other Comprehensive (Loss) Income, net of tax		1
Comprehensive Income Attributable to Parent	292	287
Progress Energy [Member]
Operating Revenues
Total operating revenues	2,536	2,541
Operating Expenses
Fuel used in electric generation and purchased power – regulated	1,032	1,043
Operation, maintenance and other	565	595
Depreciation and amortization	287	276
Property and other taxes	111	151
Total operating expenses	1,995	2,065
Gains on Sales of Other Assets and Other, net	8	1
Operating Income (Loss)	549	477
Other Income and Expenses
Other income and expenses, net	27	15
Interest Expense	168	169
Income (Loss) From Continuing Operations Before Income Taxes	408	323
Income Tax Expense (Benefit) from Continuing Operations	144	119
Income (Loss) From Continuing Operations	264	204
Income (Loss) From Discontinued Operations, net of tax	(1)	(1)
Net income (loss)	263	203
Less: Net Income Attributable to Noncontrolling Interests	3	1
Net Income (Loss) Attributable to Parent	260	202
Other Comprehensive (Loss) Income, net of tax
Pension and OPEB adjustments	1	1
Net unrealized gain (loss) on cash flow hedges		1
Reclassification into earnings from cash flow hedges	(2)	0
Other Comprehensive (Loss) Income, net of tax	(1)	2
Comprehensive Income (Loss)	262	205
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	3	1
Comprehensive Income Attributable to Parent	259	204
Duke Energy Progress [Member]
Operating Revenues
Total operating revenues	1,449	1,422
Operating Expenses
Fuel used in electric generation and purchased power – regulated	575	573
Operation, maintenance and other	375	381
Depreciation and amortization	152	144
Property and other taxes	32	67
Total operating expenses	1,134	1,165
Gains on Sales of Other Assets and Other, net	1	1
Operating Income (Loss)	316	258
Other Income and Expenses
Other income and expenses, net	20	9
Interest Expense	60	57
Income (Loss) From Continuing Operations Before Income Taxes	276	210
Income Tax Expense (Benefit) from Continuing Operations	93	77
Net Income (Loss) Attributable to Parent	183	133
Duke Energy Florida [Member]
Operating Revenues
Total operating revenues	1,086	1,116
Operating Expenses
Fuel used in electric generation and purchased power – regulated	457	470
Operation, maintenance and other	188	211
Depreciation and amortization	134	132
Property and other taxes	80	84
Total operating expenses	859	897
Operating Income (Loss)	227	219
Other Income and Expenses
Other income and expenses, net	6	5
Interest Expense	49	49
Income (Loss) From Continuing Operations Before Income Taxes	184	175
Income Tax Expense (Benefit) from Continuing Operations	71	67
Net Income (Loss) Attributable to Parent	113	108
Other Comprehensive (Loss) Income, net of tax
Net unrealized gain (loss) on cash flow hedges		1
Other Comprehensive (Loss) Income, net of tax		1
Comprehensive Income Attributable to Parent	113	109
Duke Energy Ohio [Member]
Operating Revenues
Regulated electric	339	339
Nonregulated electric and other	14	13
Regulated natural gas	233	223
Total operating revenues	586	575
Operating Expenses
Fuel used in electric generation and purchased power – regulated	115	124
Fuel used in electric generation and purchased power – nonregulated	14	13
Cost of natural gas and other	97	99
Operation, maintenance and other	128	127
Depreciation and amortization	57	57
Property and other taxes	70	68
Impairment charges		94
Total operating expenses	481	582
Gains on Sales of Other Assets and Other, net	6
Operating Income (Loss)	111	(7)
Other Income and Expenses
Other income and expenses, net	3	3
Interest Expense	20	20
Income (Loss) From Continuing Operations Before Income Taxes	94	(24)
Income Tax Expense (Benefit) from Continuing Operations	35	(9)
Income (Loss) From Continuing Operations	59	(15)
Income (Loss) From Discontinued Operations, net of tax	90	(875)
Net Income (Loss) Attributable to Parent	149	(890)
Duke Energy Indiana [Member]
Operating Revenues
Total operating revenues	788	845
Operating Expenses
Fuel used in electric generation and purchased power – regulated	294	339
Operation, maintenance and other	181	166
Depreciation and amortization	104	102
Property and other taxes	(1)	23
Total operating expenses	578	630
Operating Income (Loss)	210	215
Other Income and Expenses
Other income and expenses, net	5	7
Interest Expense	45	43
Income (Loss) From Continuing Operations Before Income Taxes	170	179
Income Tax Expense (Benefit) from Continuing Operations	62	66
Net Income (Loss) Attributable to Parent	108	113
Other Comprehensive (Loss) Income, net of tax
Reclassification into earnings from cash flow hedges	(1)	1
Other Comprehensive (Loss) Income, net of tax	(1)	1
Comprehensive Income Attributable to Parent	$ 107	$ 114