Debt And Credit Facilities (Summary Of Debt And Related Terms) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Debt Instrument [Line Items]
Unsecured debt	12,722		8,961
Secured debt	1,873		1,118
First mortgage bonds	17,856	[1]	8,182	[2]
Capital leases	1,689	[3]	306
Junior subordinated debt	309
Other debt	8		82
Tax Exempt Bonds	2,357	[4]	1,515	[5]
Non-recourse notes payable of variable interest entities	312		273
Notes payable and commercial paper	1,195	[6]	604	[7]
Fair value hedge carrying value adjustment	12		19
Unamortized debt discount and premium, net	2,185	[8]	60
Total debt	40,518	[9]	21,000	[10]
Short-term notes payable and commercial paper	(745)		(154)
Current maturities of long-term debt	(3,110)		(1,894)
Short-term non-recourse notes payable of VIEs	(312)		(273)
Total long-term debt	36,351		18,679
Foreign Currency [Abstract]
Debt assumed by Duke as a result of the merger	16,746
Duke Energy Carolinas [Member]
Debt Instrument [Line Items]
Unsecured debt	1,159		2,313
Secured debt	300		300
First mortgage bonds	6,562	[1]	5,913	[2]
Capital leases	32		34
Tax Exempt Bonds	395	[4]	415	[5]
Money pool borrowings	300		300
Fair value hedge carrying value adjustment	10		13
Unamortized debt discount and premium, net	(17)		14
Total debt	8,741		9,274
Current maturities of long-term debt	(406)		(1,178)
Total long-term debt	8,335		8,096
Progress Energy [Member]
Debt Instrument [Line Items]
Unsecured debt	4,150		4,650
Secured debt	5
First mortgage bonds	8,775	[1]	7,125	[2]
Capital leases	339		211
Junior subordinated debt	309		309
Other debt			5
Tax Exempt Bonds	910	[4]	910	[5]
Notes payable and commercial paper			671
Money pool borrowings	455		0
Unamortized debt discount and premium, net	(60)		58
Total debt	14,883		13,823
Short-term notes payable and commercial paper	0		(671)
Current maturities of long-term debt	(843)		(961)
Total long-term debt	13,585		12,191
Progress Energy Carolinas [Member]
Debt Instrument [Line Items]
Unsecured debt			500
Secured debt	5
First mortgage bonds	4,025	[1]	3,025	[2]
Capital leases	150		12
Other debt			5
Tax Exempt Bonds	669	[4]	669	[5]
Notes payable and commercial paper			188
Money pool borrowings	364		31
Unamortized debt discount and premium, net	(9)		5
Total debt	5,204		4,425
Short-term notes payable and commercial paper	0		(188)
Current maturities of long-term debt	(407)		(502)
Total long-term debt	4,433		3,704
Progress Energy Florida [Member]
Debt Instrument [Line Items]
Unsecured debt	150		150
First mortgage bonds	4,750	[1]	4,100	[2]
Capital leases	189		199
Tax Exempt Bonds	241	[4]	241	[5]
Money pool borrowings	0		8
Unamortized debt discount and premium, net	(10)		9
Total debt	5,320		4,922
Short-term notes payable and commercial paper	0		(233)
Current maturities of long-term debt	(435)		(10)
Total long-term debt	4,885		4,671
Duke Energy Ohio [Member]
Debt Instrument [Line Items]
Unsecured debt	805		1,305
First mortgage bonds	700	[1]	700	[2]
Capital leases	35		44
Other debt	8		8
Tax Exempt Bonds	479	[4]	525	[5]
Money pool borrowings	245		0
Fair value hedge carrying value adjustment	2		7
Unamortized debt discount and premium, net	(32)		34
Total debt	2,242		2,555
Current maturities of long-term debt	(261)		(507)
Total long-term debt	1,736		2,048
Duke Energy Indiana [Member]
Debt Instrument [Line Items]
Unsecured debt	1,146		1,148
First mortgage bonds	1,819	[1]	1,569	[2]
Capital leases	23		27
Tax Exempt Bonds	573	[4]	574	[5]
Money pool borrowings	231		450
Unamortized debt discount and premium, net	(9)		9
Total debt	3,783		3,759
Short-term money pool borrowings	(81)		(300)
Current maturities of long-term debt	(405)		(6)
Total long-term debt	3,297		3,453
Brazilian Reals [Member]
Foreign Currency [Abstract]
Denominated Debt	451		420
Chilean Pesos [Member]
Foreign Currency [Abstract]
Denominated Debt	61
Unsecured Debt [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	5.44%		5.93%
Year due, start	2013		2012
Year due, end	2039		2039
Unsecured Debt [Member] | Progress Energy Florida [Member]
Debt Instrument [Line Items]
Notes payable and commercial paper			233
Secured Debt [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	3.08%		3.70%
Year due, start	2013		2012
Year due, end	2037		2035
First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	(372)
Weighted-Average Rate	5.00%		5.24%
Year due, start	2013		2013
Year due, end	2042		2041
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	5.19%		8.10%
Year due, start	2013		2012
Year due, end	2051		2047
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	7.10%
Year due, end	2039
Other Debt [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	4.77%		5.25%
Year due, start			2014
Year due, end	2027		2027
Tax Exempt Bonds [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	1.39%		1.40%
Year due, start	2014		2012
Year due, end	2041		2041
Notes Payable And Commercial Paper [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	0.83%		0.61%

[1] Substantially all of the Duke Energy Registrants' electric and gas plant in service is mortgaged under mortgage bond indentures.

[2] Substantially all of the Duke Energy Registrants' electric and gas plant in service is mortgaged under the mortgage bond indentures.

[3] At December 31, 2012, capital leases of Duke Energy included $158 million and $907 million of capital lease purchase accounting adjustments for Progress Energy Carolinas and Progress Energy Florida, respectively, related to power purchase agreements that are not accounted for as leases on their financial statements because of grandfathering provisions in GAAP.

[4] $1.558 billion, $360 million, $910 million, $669 million, $241 million and $288 million were secured by first mortgage bonds at Duke Energy, Duke Energy Carolinas, Progress Energy, Progress Energy Carolinas, Progress Energy Florida and Duke Energy Indiana, respectively, and $231 million, $27 million and $204 million were secured by a letter of credit at Duke Energy, Duke Energy Ohio, and Duke Energy Indiana, respectively.

[5] $650 million, $360 million, $910 million, $669 million, $241 million and $289 million were secured by first mortgage bonds at Duke Energy, Duke Energy Carolinas, Progress Energy, Progress Energy Carolinas, Progress Energy Florida and Duke Energy Indiana, respectively, and $231 million, $27 million and $204 million were secured by a letter of credit at Duke Energy, Duke Energy Ohio, and Duke Energy Indiana, respectively.

[6] Includes $450 million that was classified as Long-term Debt on the Consolidated Balance Sheets due to the existence of long-term credit facilities that back-stop these commercial paper balances, along with Duke Energy’s ability and intent to refinance these balances on a long-term basis. The weighted-average days to maturity was 18 days.

[7] Includes $450 million that was classified as Long-term Debt on the Consolidated Balance Sheets due to the existence of long-term credit facilities that back-stop these commercial paper balances, along with Duke Energy’s ability and intent to refinance these balances on a long-term basis. The weighted-average days to maturity was 17 days.

[8] At December 31, 2012, $2.311 billion in purchase accounting adjustments related to the merger with Progress Energy were reflected in the balance for Duke Energy. See Note 2 for additional information.

[9] Includes $451 million of debt for Duke Energy that was denominated in Brazilian Reals and $61 million denominated in Chilean Pesos.

[10] Includes $420 million of debt for Duke Energy that was denominated in Brazilian Reals.