Debt and Credit Facilities (Summary of Debt Issuances) (Details) (USD $) In Millions, unless otherwise specified		9 Months Ended																									1 Months Ended		9 Months Ended		9 Months Ended					9 Months Ended					9 Months Ended					9 Months Ended				1 Months Ended
	Sep. 30, 2013	Sep. 30, 2013 January 2013 5.125% Junior Subordinated Debentures Maturing January 2073 [Member] Unsecured Debt [Member]		Sep. 30, 2013 February 2013 4.740% Term Loans Maturing June 2037 [Member] Secured Debt [Member]		Sep. 30, 2013 February 2013 2.043% Term Loans Maturing December 2030 [Member] Secured Debt [Member]		Sep. 30, 2013 March 2013 4.100% First Mortgage Bonds Maturing March 2043 [Member] First Mortgage Bonds [Member]		Sep. 30, 2013 April 2013 5.456% Non Recourse Secured Credit Facility Maturing April 2026 [Member] Bridge Loan [Member]	Sep. 30, 2013 April 2013 5.456% Non Recourse Secured Credit Facility Maturing April 2026 [Member] Secured Debt [Member]		Sep. 30, 2013 June 2013 2.100% Senior Notes Maturing June 2018 [Member] Unsecured Debt [Member]		Sep. 30, 2013 June 2013 4.00% Senior Notes Maturing June 2041 [Member] First Mortgage Bonds [Member]		Sep. 30, 2013 July 2013 4.900% First Mortgage Bonds Maturing July 2043 [Member] First Mortgage Bonds [Member]		Sep. 30, 2013 July 2013 0.619% First Mortgage Bonds Maturing July 2016 [Member] First Mortgage Bonds [Member]		Sep. 30, 2013 August 2013 11.000% Non Convertible Debentures Maturing August 2018 [Member] Unsecured Debt [Member]		Sep. 30, 2013 September 2013 3.800% First Mortgage Bonds Maturing September 2023 [Member] First Mortgage Bonds [Member]		Sep. 30, 2013 September 2013 0.400% First Mortgage Bonds Maturing March 2015 [Member] First Mortgage Bonds [Member]		Oct. 31, 2013 October 2013 3.950% Senior Notes Maturing October 2023 [Member] Unsecured Debt [Member] Subsequent Event [Member]		Sep. 30, 2013 Progress Energy [Member] January 2013 5.125% Junior Subordinated Debentures Maturing January 2073 [Member] Corporate Debt Securities [Member]	Sep. 30, 2013 Duke Energy Progress [Member]	Sep. 30, 2013 Duke Energy Progress [Member] March 2013 4.100% First Mortgage Bonds Maturing March 2043 [Member] First Mortgage Bonds [Member]		Sep. 30, 2013 Duke Energy Progress [Member] June 2013 4.00% Senior Notes Maturing June 2041 [Member] First Mortgage Bonds [Member]		Sep. 30, 2013 Duke Energy Ohio [Member]	Sep. 30, 2013 Duke Energy Ohio [Member] September 2013 3.800% First Mortgage Bonds Maturing September 2023 [Member] First Mortgage Bonds [Member]		Sep. 30, 2013 Duke Energy Ohio [Member] September 2013 0.400% First Mortgage Bonds Maturing March 2015 [Member] First Mortgage Bonds [Member]		Sep. 30, 2013 Duke Energy Indiana [Member]	Sep. 30, 2013 Duke Energy Indiana [Member] July 2013 4.900% First Mortgage Bonds Maturing July 2043 [Member] First Mortgage Bonds [Member]		Sep. 30, 2013 Duke Energy Indiana [Member] July 2013 0.619% First Mortgage Bonds Maturing July 2016 [Member] First Mortgage Bonds [Member]		Sep. 30, 2013 Parent Company [Member]	Sep. 30, 2013 Parent Company [Member] January 2013 5.125% Junior Subordinated Debentures Maturing January 2073 [Member] Unsecured Debt [Member]		Sep. 30, 2013 Parent Company [Member] June 2013 2.100% Senior Notes Maturing June 2018 [Member] Unsecured Debt [Member]		Oct. 31, 2013 Parent Company [Member] October 2013 3.950% Senior Notes Maturing October 2023 [Member] Unsecured Debt [Member] Subsequent Event [Member]
Debt Instrument [Line Items]
Debt issuance date		Jan. 31, 2013		Feb. 28, 2013		Feb. 28, 2013		Mar. 31, 2013			Apr. 30, 2013		Jun. 30, 2013		Jun. 30, 2013		Jul. 31, 2013		Jul. 31, 2013		Aug. 31, 2013		Sep. 30, 2013		Sep. 30, 2013		Oct. 31, 2013				Mar. 31, 2013		Jun. 30, 2013			Sep. 30, 2013		Sep. 30, 2013			Jul. 31, 2013		Jul. 31, 2013			Jan. 31, 2013		Jun. 30, 2013		Oct. 31, 2013
Debt maturity date		Jan. 31, 2073		Jun. 30, 2037		Dec. 31, 2030		Mar. 31, 2043			Apr. 30, 2026		Jun. 30, 2018		Jun. 30, 2041		Jul. 31, 2043		Jul. 31, 2016				Sep. 30, 2023		Mar. 31, 2015		Oct. 31, 2023				Mar. 31, 2043		Jun. 30, 2041			Sep. 30, 2023		Mar. 31, 2015			Jul. 31, 2043		Jul. 31, 2016			Jan. 31, 2073		Jun. 30, 2018		Oct. 31, 2023
Debt maturity date, start																					Aug. 31, 2018
Debt maturity date, end																					Aug. 31, 2023
Debt issuances	$ 3,771	$ 500	[1]	$ 220	[2]	$ 203	[2],[3]	$ 500	[4]		$ 230	[5]	$ 500	[6]	$ 48	[7]	$ 350	[8]	$ 150	[8],[9]	$ 220	[10],[11]	$ 300	[12]	$ 150	[12],[13]	$ 400	[14]		$ 548	$ 500	[4]	$ 48	[7]	$ 450	$ 300	[12]	$ 150	[12],[13]	$ 500	$ 350	[8]	$ 150	[8],[9]	$ 1,400	$ 500	[1]	$ 500	[6]	$ 400	[14]
Interest rate		5.125%		4.74%		2.043%		4.10%			5.456%		2.10%		4.00%		4.90%		0.619%		11.00%		3.80%		0.40%		3.95%		7.10%		4.10%		4.00%			3.80%		0.40%			4.90%		0.619%			5.125%		2.10%		3.95%
Debt instrument, call date, earliest		Jan. 31, 2018													Jun. 30, 2023																		Jun. 30, 2023													Jan. 31, 2018
Payments for the redemption of debt										190			250		48		400				200		250						300				48			250					400							250
Percentage of debt hedged by interest rate derivatives						95.00%					75.00%
Incremental debt proceeds											$ 40
Fixed credit spread																			0.35%						0.14%													0.14%					0.35%

[1] Callable after January 2018 at par. Proceeds from the issuance were used to redeem the $300 million 7.10% Cumulative Quarterly Income Preferred Securities (QUIPS). The securities were redeemed at par plus accrued and unpaid distributions, payable upon presentation on the redemption date. The remaining net proceeds were used to repay a portion of outstanding commercial paper and for general corporate purposes. See Note 11 for additional information about the QUIPS.

[2] Represents the conversion of construction loans related to a renewable energy project issued in December 2012 to term loans. No cash proceeds were received in conjunction with the conversion. The term loans have varying maturity dates. The maturity date presented represents the latest date for all components of the respective loans.

[3] The debt is floating rate. Duke Energy has entered into a pay fixed-receive floating interest rate swap for 95 percent of the loans.

[4] Proceeds from the issuance were used to repay notes payable to affiliated companies as well as for general corporate purposes.

[5] Represents primarily the conversion of a $190 million bridge loan issued in conjunction with the acquisition of Ibener in December 2012. Duke Energy received incremental proceeds of $40 million upon conversion of the bridge loan. The debt is floating rate and is denominated in U.S. dollars. Duke Energy has entered into a pay fixed-receive floating interest rate swap for 75 percent of the loan.

[6] Proceeds from the issuance were used to repay $250 million of current maturities. The remaining net proceeds were used for general corporate purposes, including the repayment of outstanding commercial paper.

[7] Callable after June 2023 at par. Proceeds from the issuance were used to redeem $48 million of First Mortgage Bonds with a higher interest rate.

[8] Proceeds from the issuances were used to repay $400 million of current maturities.

[9] The debt is floating rate based on 3-month London Interbank Offered Rate (LIBOR) and a fixed spread of 35 basis points.

[10] Proceeds from the issuance were used to repay $200 million of current maturities. The maturity date included above applies to half of the instrument. The remaining half matures in August 2018.

[11] The debt is floating rate based on a consumer price index and an overnight funds rate in Brazil. The debt is denominated in Brazilian Real.

[12] Proceeds from the issuances were used for general corporate purposes including the repayment of short-term notes payable, a portion of which was incurred to fund the retirement of $250 million of first mortgage bonds that matured in the first half of 2013.

[13] The debt is floating rate based on 3-month LIBOR plus a fixed spread of 14 basis points.

[14] Proceeds from the issuance were used to repay commercial paper as well as for general corporate purposes.