Consolidated Statements of Operations (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Operating Revenues [Abstract]
Regulated electric	$ 5,578	$ 4,889
Nonregulated electric, natural gas, and other	824	824
Regulated natural gas	222	185
Total operating revenues	6,624	5,898
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	2,000	1,703
Fuel used in electric generation and purchased power - nonregulated	409	454
Cost of natural gas and coal sold	122	104
Operation, maintenance and other	1,506	1,421
Depreciation and amortization	790	660
Property and other taxes	358	343
Impairment charges	1,382	0
Total operating expenses	6,567	4,685
Gains (Losses) on Sales of Other Assets and Other, net	1	2
Operating Income (Loss)	58	1,215
Other Income and Expenses [Abstract]
Equity in earnings of unconsolidated affiliates	36	36
Other income and expenses, net	95	80
Total other income and expenses	131	116
Interest Expense	406	367
Income (Loss) From Continuing Operations Before Income Taxes	(217)	964
Income Tax Expense or Benefit from Continuing Operations	(127)	330
Income (Loss) from Continuing Operations	(90)	634
Income (Loss) From Discontinued Operations, net of tax	(3)	0
Net Income (Loss)	(93)	634
Less: Net Income (Loss) Attributable to Noncontrolling Interests	4	0
Net Income (Loss) Attributable to Duke Energy	(97)	634
Other Comprehensive Income(Loss), Net of Tax [Abstract]
Foreign currency translation adjustments	24	4
Pension and OPEB adjustments	(1)	3
Net unrealized gain (loss) on cash flow hedges	0	10	[1]
Other comprehensive income (loss), net of tax	23	17
Comprehensive Income (Loss)	(70)	651
Less: Comprehensive Income Attributable to Noncontrolling Interests	5
Comprehensive income (loss)	(75)	651
Income From Continuing Operations Attributable To Parent Common Shareholders [Abstract]
Basic	$ (0.13)	$ 0.89
Diluted	$ (0.13)	$ 0.89
Income (loss) from discontinued operations attributable To Duke Energy Corporation common shareholders [Abstract]
Basic	$ (0.01)	$ 0
Diluted	$ (0.01)	$ 0
Net income attributable to Duke Energy Corporation common shareholders [Abstract]
Basic	$ (0.14)	$ 0.89
Diluted	$ (0.14)	$ 0.89
Weighted-average shares outstanding [Abstract]
Basic	706	705
Diluted	706	705
Duke Energy Carolinas [Member]
Operating Revenues [Abstract]
Total operating revenues	2,000	1,729
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	658	518
Operation, maintenance and other	487	457
Depreciation and amortization	242	222
Property and other taxes	104	100
Total operating expenses	1,491	1,297
Gains (Losses) on Sales of Other Assets and Other, net	0	2
Operating Income (Loss)	509	434
Other Income and Expenses [Abstract]
Other income and expenses, net	49	36
Interest Expense	101	82
Income (Loss) From Continuing Operations Before Income Taxes	457	388
Income Tax Expense or Benefit from Continuing Operations	171	144
Net Income (Loss)	286	244
Other Comprehensive Income(Loss), Net of Tax [Abstract]
Reclassification into earnings from cash flow hedges	1	0
Other comprehensive income (loss), net of tax	1	0
Comprehensive income (loss)	287	244
Progress Energy [Member]
Operating Revenues [Abstract]
Total operating revenues	2,541	2,186
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	1,043	860
Operation, maintenance and other	595	561
Depreciation and amortization	276	194
Property and other taxes	151	141
Total operating expenses	2,065	1,756
Gains (Losses) on Sales of Other Assets and Other, net	1
Operating Income (Loss)	477	430
Other Income and Expenses [Abstract]
Other income and expenses, net	15	23
Interest Expense	169	198
Income (Loss) From Continuing Operations Before Income Taxes	323	255
Income Tax Expense or Benefit from Continuing Operations	119	101
Income (Loss) from Continuing Operations	204	154
Income (Loss) From Discontinued Operations, net of tax	(1)
Net Income (Loss)	203	154
Less: Net Income (Loss) Attributable to Noncontrolling Interests	1	1
Net Income (Loss) Attributable to Duke Energy	202	153
Other Comprehensive Income(Loss), Net of Tax [Abstract]
Reclassification into earnings from pension and OPEB adjustments	1	1
Net unrealized gain (loss) on cash flow hedges	1	1
Other comprehensive income (loss), net of tax	2	2
Comprehensive Income (Loss)	205	156
Duke Energy Progress [Member]
Operating Revenues [Abstract]
Total operating revenues	1,422	1,216
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	573	455
Operation, maintenance and other	381	352
Depreciation and amortization	144	137
Property and other taxes	67	60
Total operating expenses	1,165	1,004
Gains (Losses) on Sales of Other Assets and Other, net	1	0
Operating Income (Loss)	258	212
Other Income and Expenses [Abstract]
Other income and expenses, net	9	14
Interest Expense	57	48
Income (Loss) From Continuing Operations Before Income Taxes	210	178
Income Tax Expense or Benefit from Continuing Operations	77	68
Net Income (Loss)	133	110
Duke Energy Florida [Member]
Operating Revenues [Abstract]
Total operating revenues	1,116	968
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	470	405
Operation, maintenance and other	211	211
Depreciation and amortization	132	52
Property and other taxes	84	79
Total operating expenses	897	747
Operating Income (Loss)	219	221
Other Income and Expenses [Abstract]
Other income and expenses, net	5	8
Interest Expense	49	49
Income (Loss) From Continuing Operations Before Income Taxes	175	180
Income Tax Expense or Benefit from Continuing Operations	67	70
Net Income (Loss)	108	110
Other Comprehensive Income(Loss), Net of Tax [Abstract]
Net unrealized gain (loss) on cash flow hedges	1	0
Other comprehensive income (loss), net of tax	1
Comprehensive income (loss)	109	110
Duke Energy Ohio [Member]
Operating Revenues [Abstract]
Regulated electric	367	333
Nonregulated electric, natural gas, and other	173	228
Regulated natural gas	223	186
Total operating revenues	763	747
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	124	103
Fuel used in electric generation and purchased power - nonregulated	131	240
Cost of natural gas and coal sold	102	76
Operation, maintenance and other	181	185
Depreciation and amortization	91	88
Property and other taxes	75	72
Impairment charges	1,417
Total operating expenses	2,121	764
Operating Income (Loss)	(1,358)	(17)
Other Income and Expenses [Abstract]
Other income and expenses, net	3	2
Interest Expense	22	18
Income (Loss) From Continuing Operations Before Income Taxes	(1,377)	(33)
Income Tax Expense or Benefit from Continuing Operations	(487)	(12)
Net Income (Loss)	(890)	(21)
Other Comprehensive Income(Loss), Net of Tax [Abstract]
Pension and OPEB adjustments	0	1
Other comprehensive income (loss), net of tax	0	1
Comprehensive income (loss)	(890)	(20)
Duke Energy Indiana [Member]
Operating Revenues [Abstract]
Total operating revenues	845	724
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	339	293
Operation, maintenance and other	166	150
Depreciation and amortization	102	78
Property and other taxes	23	22
Total operating expenses	630	543
Operating Income (Loss)	215	181
Other Income and Expenses [Abstract]
Other income and expenses, net	7	4
Interest Expense	43	41
Income (Loss) From Continuing Operations Before Income Taxes	179	144
Income Tax Expense or Benefit from Continuing Operations	66	54
Net Income (Loss)	113	90
Other Comprehensive Income(Loss), Net of Tax [Abstract]
Reclassification into earnings from cash flow hedges	1	0
Other comprehensive income (loss), net of tax	1	0
Comprehensive income (loss)	$ 114	$ 90

[1] Net of $4 million tax expense in 2013.