Consolidated Statements Of Operations (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Operating Revenues
Regulated electric	$ 15,621		$ 10,589		$ 10,723
Non-regulated electric, natural gas, and other	3,534		3,383		2,930
Regulated natural gas	469		557		619
Total operating revenues	19,624		14,529		14,272
Operating Expenses
Fuel used in electric generation and purchased power - regulated	5,582		3,309		3,345
Fuel used in electric generation and purchased power - non-regulated	1,722		1,488		1,199
Cost of natural gas and coal sold	264		348		381
Operation, maintenance and other	5,006		3,770		3,825
Depreciation and amortization	2,289		1,806		1,786
Property and other taxes	985		704		702
Impairment charges	666		335		726
Total operating expenses	16,514		11,760		11,964
Gains (losses) on sales of other assets and other, net	16		8		153
Operating Income	3,126		2,777		2,461
Other Income and Expenses
Equity in earnings of unconsolidated affiliates	148		160		116
Impairments and gains on sales of unconsolidated affiliates	22		11		103
Other income and expenses, net	397		376		370
Total Other Income and Expense	567		547		589
Interest Expense	1,242		859		840
Income From Continuing Operations Before Income Taxes	2,451		2,465		2,210
Income Tax Expense or Benefit from Continuing Operations	705		752		890
Income (Loss) from Continuing Operations	1,746		1,713		1,320
Income (Loss) From Discontinued Operations, net of tax	36		1		3
Net Income	1,782		1,714		1,323
Less: Net Income (Loss) Attributable to Noncontrolling Interests	14		8		3
Net Income Attributable to Duke Energy Corporation	1,768		1,706		1,320
Net Income Available to Parent	1,780	[1]
Other comprehensive income(loss), net of tax
Pension and OPEB related adjustments	(19)	[2]	49	[2]	(276)	[2]
Net unrealized gain (loss) on cash flow hedges	(28)	[3]	(57)	[3]	1	[3]
Reclassification into earnings from cash flow hedges	(1)	[4]	4	[4]	3	[4]
Other Comprehensive Income Unrealized Holding Gain Loss On Auction Rate Securities Arising During Period Net Of Tax	9	[5]	8	[5]	14	[5]
Other comprehensive income (loss), net of tax	(76)		(243)		373
Comprehensive income	1,706		1,471		1,696
Less: Comprehensive Income attributable to noncontrolling interests	10		1		2
Comprehensive income	1,696		1,470		1,694
Income from continuing operations attributable to Duke Energy Corporation common shareholders
Basic	$ 3.01		$ 3.83		$ 2.99
Diluted	$ 3.01		$ 3.83		$ 2.99
Income (loss) from discontinued operations attributable To Duke Energy Corporation common shareholders
Basic	$ 0.06		$ 0		$ 0.01
Diluted	$ 0.06		$ 0		$ 0.01
Net income attributable to Duke Energy Corporation common shareholders
Basic	$ 3.07		$ 3.83		$ 3.00
Diluted	$ 3.07		$ 3.83		$ 3.00
Dividends declared per share	$ 3.03		$ 2.97		$ 2.91
Weighted-average shares outstanding
Basic	574		444		439
Diluted	575		444		440
Duke Energy Carolinas [Member]
Operating Revenues
Total operating revenues	6,665		6,493		6,424
Operating Expenses
Fuel used in electric generation and purchased power - regulated	1,864		1,944		1,944
Operation, maintenance and other	1,979		1,904		1,907
Depreciation and amortization	921		814		787
Property and other taxes	365		340		348
Impairment charges	31		12		0
Total operating expenses	5,160		5,014		4,986
Gains (losses) on sales of other assets and other, net	12		1		7
Operating Income	1,517		1,480		1,445
Other Income and Expenses
Other income and expenses, net	185		186		212
Interest Expense	384		360		362
Income From Continuing Operations Before Income Taxes	1,318		1,306		1,295
Income Tax Expense or Benefit from Continuing Operations	453		472		457
Net Income	865		834		838
Other comprehensive income(loss), net of tax
Reclassification into earnings from cash flow hedges	2	[6]	3	[6]	4	[6]
Other Comprehensive Income Unrealized Holding Gain Loss On Auction Rate Securities Arising During Period Net Of Tax	1	[7]			7	[7]
Other comprehensive income (loss), net of tax	3		3		11
Comprehensive income	868		837		849
Progress Energy [Member]
Operating Revenues
Total operating revenues	9,405		8,948		10,223
Operating Expenses
Fuel used in electric generation and purchased power - regulated	4,304		4,043		4,621
Operation, maintenance and other	2,445		2,060		2,045
Depreciation and amortization	747		701		920
Property and other taxes	570		562		580
Impairment charges	200		3		5
Total operating expenses	8,266		7,369		8,171
Gains (losses) on sales of other assets and other, net	(2)		4		(8)
Operating Income	1,137		1,583		2,044
Other Income and Expenses
Other income and expenses, net	130		52		109
Interest Expense	740		725		747
Income From Continuing Operations Before Income Taxes	527		910		1,406
Income Tax Expense or Benefit from Continuing Operations	172		323		539
Income (Loss) from Continuing Operations	355		587		867
Income (Loss) From Discontinued Operations, net of tax	52		(5)		(4)
Net Income	407		582		863
Less: Net Income (Loss) Attributable to Noncontrolling Interests	7		7		7
Net Income Attributable to Duke Energy Corporation	400		575		856
Other comprehensive income(loss), net of tax
Pension and OPEB related adjustments	(4)	[8]	34	[8]	(13)	[8]
Reclassification into earnings from pension and OPEB adjustments	2	[9]	5	[9]	3	[9]
Net unrealized gain (loss) on cash flow hedges	(5)	[10]	(87)	[10]	(34)	[10]
Reclassification into earnings from cash flow hedges	8	[11]	8	[11]	6	[11]
Reclassification of cash flow hedges to regulatory assets	97	[12]
Other comprehensive income (loss), net of tax	98		(40)		(38)
Comprehensive income	505		542		825
Less: Comprehensive Income attributable to noncontrolling interests	7		7		7
Comprehensive income	498		535		818
Progress Energy Carolinas [Member]
Operating Revenues
Total operating revenues	4,706		4,547		4,933
Operating Expenses
Fuel used in electric generation and purchased power - regulated	1,895		1,755		2,008
Operation, maintenance and other	1,494		1,191		1,158
Depreciation and amortization	535		514		478
Property and other taxes	219		211		218
Impairment charges	54		3		5
Total operating expenses	4,197		3,674		3,867
Gains (losses) on sales of other assets and other, net	1		3		1
Operating Income	510		876		1,067
Other Income and Expenses
Other income and expenses, net	79		80		71
Interest Expense	207		184		186
Income From Continuing Operations Before Income Taxes	382		772		952
Income Tax Expense or Benefit from Continuing Operations	110		256		350
Net Income	272		516		602
Less: Net Income (Loss) Attributable to Noncontrolling Interests					(1)
Net Income Attributable to Duke Energy Corporation	272		516		603
Less: Preferred Stock Dividend Requirement	3		3		3
Net Income Available to Parent	269		513		600
Other comprehensive income(loss), net of tax
Net unrealized gain (loss) on cash flow hedges	(4)	[13]	(43)	[13]	(10)	[13]
Reclassification into earnings from cash flow hedges	4	[14]	5	[14]	4	[14]
Reclassification of cash flow hedges to regulatory assets	71	[15]
Other comprehensive income (loss), net of tax	71		(38)		(6)
Comprehensive income	343		478		596
Less: Comprehensive Income attributable to noncontrolling interests					(1)
Comprehensive income	343		478		597
Progress Energy Florida [Member]
Operating Revenues
Total operating revenues	4,689		4,392		5,276
Operating Expenses
Fuel used in electric generation and purchased power - regulated	2,409		2,288		2,613
Operation, maintenance and other	969		883		915
Depreciation and amortization	192		169		426
Property and other taxes	346		351		362
Impairment charges	146
Total operating expenses	4,062		3,691		4,316
Gains (losses) on sales of other assets and other, net	2		2		(5)
Operating Income	629		703		955
Other Income and Expenses
Other income and expenses, net	39		30		32
Interest Expense	255		239		258
Income From Continuing Operations Before Income Taxes	413		494		729
Income Tax Expense or Benefit from Continuing Operations	147		180		276
Net Income	266		314		453
Less: Preferred Stock Dividend Requirement	2		2		2
Net Income Available to Parent	264		312		451
Other comprehensive income(loss), net of tax
Net unrealized gain (loss) on cash flow hedges			(23)	[16]	(7)	[16]
Reclassification into earnings from cash flow hedges	1	[17]
Reclassification of cash flow hedges to regulatory assets	26	[18]
Other comprehensive income (loss), net of tax	27		(23)		(7)
Comprehensive income	293		291		446
Duke Energy Ohio [Member]
Operating Revenues
Regulated electric	1,386		1,518		1,823
Non-regulated electric, natural gas, and other	1,295		1,105		885
Regulated natural gas	471		558		621
Total operating revenues	3,152		3,181		3,329
Operating Expenses
Fuel used in electric generation and purchased power - regulated	475		380		490
Fuel used in electric generation and purchased power - non-regulated	832		653		465
Cost of natural gas and coal sold	142		209		269
Operation, maintenance and other	797		885		836
Depreciation and amortization	338		335		400
Property and other taxes	224		260		260
Impairment charges	2		89		837
Total operating expenses	2,810		2,811		3,557
Gains (losses) on sales of other assets and other, net	7		5		3
Operating Income	349		375		(225)
Other Income and Expenses
Other income and expenses, net	13		19		25
Interest Expense	89		104		109
Income From Continuing Operations Before Income Taxes	273		290		(309)
Income Tax Expense or Benefit from Continuing Operations	98		96		132
Net Income	175		194		(441)
Other comprehensive income(loss), net of tax
Pension and OPEB related adjustments	27	[19]	(6)	[19]	8	[19]
Reclassification into earnings from cash flow hedges	0	[20]	0	[20]	(1)	[20]
Other comprehensive income (loss), net of tax	27		(6)		7
Comprehensive income	202		188		(434)
Duke Energy Indiana [Member]
Operating Revenues
Total operating revenues	2,717		2,622		2,520
Operating Expenses
Fuel used in electric generation and purchased power - regulated	1,088		986		912
Operation, maintenance and other	655		647		611
Depreciation and amortization	389		391		375
Property and other taxes	81		82		70
Impairment charges	579		234		44
Total operating expenses	2,792		2,340		2,012
Gains (losses) on sales of other assets and other, net	0		0		(2)
Operating Income	(75)		282		506
Other Income and Expenses
Other income and expenses, net	90		97		70
Interest Expense	138		137		135
Income From Continuing Operations Before Income Taxes	(123)		242		441
Income Tax Expense or Benefit from Continuing Operations	(73)		74		156
Net Income	(50)		168		285
Other comprehensive income(loss), net of tax
Reclassification into earnings from cash flow hedges	(2)	[21]	(1)	[21]	(2)	[21]
Other comprehensive income (loss), net of tax	(2)		(1)		(2)
Comprehensive income	$ (52)		$ 167		$ 283

[1] For the year ended December 31, 2012, consolidated net income of $1,782 million includes $2 million attributable to preferred shareholders of subsidiaries. Income attributable to preferred shareholders of subsidiaries is not a component of total equity and is excluded from the table above.

[2] Net of $9 million tax expense in 2012, $23 million tax benefit in 2011 and $150 million tax expense in 2010.

[3] Net of $6 million tax expense in 2012, $31 million tax benefit in 2011 and $1 million tax expense in 2010.

[4] Net of $1 million tax benefit in 2012, $1 million tax expense in 2011 and insignificant tax expense in 2010.

[5] Net of $4 million tax expense in 2012, $4 million tax expense in 2011 and $8 million tax expense in 2010.

[6] Net of $1 million tax expense in 2012, $2 million tax expense in 2011 and $2 million tax expense in 2010.

[7] Net of $1 million tax expense in 2012 and $5 million tax expense in 2010.

[8] Net of $1 million tax benefit in 2012, $24 million tax expense in 2011 and $8 million tax benefit in 2010.

[9] Net of $1 million tax expense in 2012, $3 million tax expense in 2011 and $2 million tax expense in 2010.

[10] Net of $3 million tax benefit in 2012, $56 million tax benefit in 2011 and $22 million tax benefit in 2010.

[11] Net of $6 million tax expense in 2012, $5 million tax expense in 2011 and $4 million tax expense in 2010.

[12] Net of $62 million tax expense in 2012.

[13] Net of $3 million tax benefit in 2012, $28 million tax benefit in 2011 and $6 million tax benefit in 2010.

[14] Net of $2 million tax expense in 2012, $3 million tax expense in 2011 and $3 million tax expense in 2010.

[15] Net of $46 million tax expense in 2012.

[16] Net of $15 million tax benefit in 2011 and $4 million tax benefit in 2010.

[17] Net of $1 million tax expense in 2012.

[18] Net of $16 million tax expense in 2012.

[19] Net of $8 million tax expense in 2012, insignificant tax expense in 2011 and $4 million tax expense in 2010.

[20] Net of $1 million tax benefit in 2010.

[21] Net of tax benefit of $1 million in 2012, 2011 and 2010.