Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Operating Revenues [Abstract]
Regulated electric	$ 4,834		$ 2,628		$ 9,723		$ 5,129
Non-regulated electric, natural gas, and other	951		868		1,775		1,826
Regulated natural gas	94		81		279		252
Total operating revenues	5,879		3,577		11,777		7,207
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	1,678		849		3,381		1,626
Fuel used in electric generation and purchased power - non-regulated	447		396		901		844
Cost of natural gas and coal sold	43		42		147		144
Operation, maintenance and other	1,504		862		2,925		1,608
Depreciation and amortization	678		475		1,338		954
Property and other taxes	323		171		666		355
Impairment charges	386		0		386		402
Total operating expenses	5,059		2,795		9,744		5,933
Gains (Losses) on Sales of Other Assets and Other, net	1		4		3		7
Operating Income (Loss)	821		786		2,036		1,281
Other Income and Expenses [Abstract]
Equity in earnings of unconsolidated affiliates	22		40		58		85
Impairments and gains on sales of unconsolidated affiliates	(6)		(1)		(6)		(6)
Other income and expenses, net	54		70		134		159
Total other income and expenses	70		109		186		238
Interest Expense	381		232		748		456
Income (Loss) From Continuing Operations Before Income Taxes	510		663		1,474		1,063
Income Tax Expense or Benefit from Continuing Operations	165		214		495		317
Income (Loss) from Continuing Operations	345		449		979		746
Income (Loss) From Discontinued Operations, net of tax	(3)		(1)		(3)		1
Net Income (Loss)	342		448		976		747
Less: Net Income (Loss) Attributable to Noncontrolling Interests	3		4		3		8
Net Income (Loss) Attributable to Duke Energy	339		444		973		739
Other Comprehensive Income(Loss), Net of Tax [Abstract]
Pension and OPEB related adjustments	2		2		5		6
Net unrealized gain (loss) on cash flow hedges	44	[1]	(30)	[1]	54	[1]	(17)	[1]
Reclassification into earnings from cash flow hedges			3				2
Other Comprehensive Income Unrealized Holding Gain Loss On Auction Rate Securities Arising During Period Net Of Tax			6				6
Other comprehensive income (loss), net of tax	(91)		(150)		(74)		(90)
Comprehensive Income (Loss)	251		298		902		657
Less: Comprehensive Income Attributable to Noncontrolling Interests	(1)		0		(1)		4
Comprehensive income (loss)	252		298		903		653
Income From Continuing Operations Attributable To Parent Common Shareholders [Abstract]
Basic	$ 0.48		$ 0.99		$ 1.37		$ 1.65
Diluted	$ 0.48		$ 0.99		$ 1.37		$ 1.65
Income (loss) from discontinued operations attributable To Duke Energy Corporation common shareholders [Abstract]
Basic	$ 0		$ 0		$ 0		$ 0
Diluted	$ 0		$ 0		$ 0		$ 0
Net income attributable to Duke Energy Corporation common shareholders [Abstract]
Basic	$ 0.48		$ 0.99		$ 1.37		$ 1.65
Diluted	$ 0.48		$ 0.99		$ 1.37		$ 1.65
Dividends declared per share	$ 1.545		$ 1.515		$ 2.31		$ 2.265
Weighted-average shares outstanding [Abstract]
Basic	706		446		705		446
Diluted	706		446		706		446
Duke Energy Carolinas [Member]
Operating Revenues [Abstract]
Total operating revenues	1,591		1,616		3,320		3,117
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	443		442		961		822
Operation, maintenance and other	479		476		936		807
Depreciation and amortization	226		226		448		454
Property and other taxes	92		89		192		179
Total operating expenses	1,240		1,233		2,537		2,262
Gains (Losses) on Sales of Other Assets and Other, net	0		3		2		6
Operating Income (Loss)	351		386		785		861
Other Income and Expenses [Abstract]
Total other income and expenses	29		43		65		82
Interest Expense	91		93		173		190
Income (Loss) From Continuing Operations Before Income Taxes	289		336		677		753
Income Tax Expense or Benefit from Continuing Operations	108		125		252		276
Net Income (Loss)	181		211		425		477
Other Comprehensive Income(Loss), Net of Tax [Abstract]
Reclassification into earnings from cash flow hedges	0		2		0		2
Other comprehensive income (loss), net of tax							2
Comprehensive Income (Loss)	181		213		425		479
Progress Energy [Member]
Operating Revenues [Abstract]
Total operating revenues	2,281		2,288		4,467		4,390
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	918		1,002		1,778		1,903
Operation, maintenance and other	533		637		1,094		1,172
Depreciation and amortization	210		231		404		397
Property and other taxes	141		142		282		280
Impairment charges	366		0		366		0
Total operating expenses	2,168		2,012		3,924		3,752
Gains (Losses) on Sales of Other Assets and Other, net	1		1		1		2
Operating Income (Loss)	114		277		544		640
Other Income and Expenses [Abstract]
Total other income and expenses	14		26		37		65
Interest Expense	160		193		358		378
Income (Loss) From Continuing Operations Before Income Taxes	(32)		110		223		327
Income Tax Expense or Benefit from Continuing Operations	(19)		42		82		118
Income (Loss) from Continuing Operations	(13)		68		141		209
Income (Loss) From Discontinued Operations, net of tax	(4)		(4)		(4)		7
Net Income (Loss)	(17)		64		137		216
Less: Net Income (Loss) Attributable to Noncontrolling Interests	0		1		1		3
Net Income (Loss) Attributable to Duke Energy	(17)		63		136		213
Other Comprehensive Income(Loss), Net of Tax [Abstract]
Reclassification into earnings from pension and OPEB adjustments	0		0		1		1
Net unrealized gain (loss) on cash flow hedges	2		(2)		3		0
Reclassification into earnings from cash flow hedges	0		(2)		0		0
Other comprehensive income (loss), net of tax	2		(4)		4		1
Comprehensive income (loss)	(15)		60		141		217
Duke Energy Progress [Member]
Operating Revenues [Abstract]
Total operating revenues	1,135		1,090		2,351		2,180
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	441		433		896		853
Operation, maintenance and other	340		388		692		762
Depreciation and amortization	113		134		250		268
Property and other taxes	53		52		113		108
Impairment charges	22		0		22		0
Total operating expenses	969		1,007		1,973		1,991
Gains (Losses) on Sales of Other Assets and Other, net	0		0		0		1
Operating Income (Loss)	166		83		378		190
Other Income and Expenses [Abstract]
Total other income and expenses	8		16		22		36
Interest Expense	47		53		95		104
Income (Loss) From Continuing Operations Before Income Taxes	127		46		305		122
Income Tax Expense or Benefit from Continuing Operations	50		15		118		39
Net Income (Loss)	77		31		187		83
Less: Preferred Stock Dividend Requirement	0		0		0		1
Net Income (Loss) Available to Parent	77		31		187		82
Other Comprehensive Income(Loss), Net of Tax [Abstract]
Net unrealized gain (loss) on cash flow hedges	0		(4)		0		(1)
Reclassification into earnings from cash flow hedges	0		(2)		0		0
Other comprehensive income (loss), net of tax	0		(6)		0		(1)
Comprehensive income (loss)	77		25		187		82
Duke Energy Florida [Member]
Operating Revenues [Abstract]
Total operating revenues	1,142		1,196		2,110		2,206
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	478		568		883		1,050
Operation, maintenance and other	198		251		409		415
Depreciation and amortization	90		92		142		119
Property and other taxes	85		89		164		172
Impairment charges	345		0		345		0
Total operating expenses	1,196		1,000		1,943		1,756
Gains (Losses) on Sales of Other Assets and Other, net	1		0		1		1
Operating Income (Loss)	(53)		196		168		451
Other Income and Expenses [Abstract]
Total other income and expenses	5		9		13		18
Interest Expense	43		69		92		132
Income (Loss) From Continuing Operations Before Income Taxes	(91)		136		89		337
Income Tax Expense or Benefit from Continuing Operations	(34)		53		36		126
Net Income (Loss)	(57)		83		53		211
Less: Preferred Stock Dividend Requirement	0		0		0		1
Net Income (Loss) Available to Parent	(57)		83		53		210
Other Comprehensive Income(Loss), Net of Tax [Abstract]
Net unrealized gain (loss) on cash flow hedges	0		(1)		0		0
Comprehensive income (loss)	(57)		82		53		211
Duke Energy Ohio [Member]
Operating Revenues [Abstract]
Regulated electric	339		336		672		660
Non-regulated electric, natural gas, and other	378		299		606		716
Regulated natural gas	94		82		280		253
Total operating revenues	811		717		1,558		1,629
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	103		120		206		234
Fuel used in electric generation and purchased power - non-regulated	222		176		462		415
Cost of natural gas and coal sold	17		12		93		87
Operation, maintenance and other	212		175		397		371
Depreciation and amortization	89		80		177		163
Property and other taxes	64		60		136		128
Total operating expenses	707		623		1,471		1,398
Gains (Losses) on Sales of Other Assets and Other, net	4		1		4		2
Operating Income (Loss)	108		95		91		233
Other Income and Expenses [Abstract]
Total other income and expenses	1		4		3		8
Interest Expense	18		25		36		49
Income (Loss) From Continuing Operations Before Income Taxes	91		74		58		192
Income Tax Expense or Benefit from Continuing Operations	33		29		21		73
Net Income (Loss)	58		45		37		119
Other Comprehensive Income(Loss), Net of Tax [Abstract]
Pension and OPEB related adjustments	0		0		(1)		(1)
Other comprehensive income (loss), net of tax					1		1
Comprehensive income (loss)	58		45		38		120
Duke Energy Indiana [Member]
Operating Revenues [Abstract]
Total operating revenues	700		685		1,424		1,373
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	276		287		569		570
Operation, maintenance and other	163		151		313		311
Depreciation and amortization	77		96		155		192
Property and other taxes	16		17		38		38
Impairment charges	0		0		0		400
Total operating expenses	532		551		1,075		1,511
Operating Income (Loss)	168		134		349		(138)
Other Income and Expenses [Abstract]
Total other income and expenses	6		19		10		42
Interest Expense	43		36		84		70
Income (Loss) From Continuing Operations Before Income Taxes	131		117		275		(166)
Income Tax Expense or Benefit from Continuing Operations	49		40		103		(76)
Net Income (Loss)	82		77		172		(90)
Other Comprehensive Income(Loss), Net of Tax [Abstract]
Reclassification into earnings from cash flow hedges	(1)		0		(1)		(1)
Other comprehensive income (loss), net of tax					(1)		(1)
Comprehensive income (loss)	$ 81		$ 77		$ 171		$ (91)

[1] Net of $14 million tax expense and $18 million tax expense for the three and six months ended June 30, 2013 and $14 million tax benefit and $9 million tax benefit for the three and six months ended June 30, 2012.