Debt And Credit Facilities (Summary Of Debt Issuances) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Debt Instrument [Line Items]
Total Issuances	$ 1,653
Payments for the redemption of long-term debt	747		821
Unsecured Debt [Member] | January 2013 [Member] | January 2073 [Member]
Debt Instrument [Line Items]
Unsecured debt issuances	500	[1]
Interest Rate	5.125%
Debt instrument, call date, earliest	Jan. 01, 2018
Secured Debt [Member] | June 2013 [Member]
Debt Instrument [Line Items]
Interest Rate	1.009%
Secured Debt [Member] | April 2013 [Member] | April 2026 [Member]
Debt Instrument [Line Items]
Secured debt issuances	230	[2]
Interest Rate	5.456%
Percentage of debt hedged by interest rate derivatives	75.00%
Incremental debt proceeds	40
Secured Debt [Member] | February 2013 [Member] | June 2037 [Member]
Debt Instrument [Line Items]
Secured debt issuances	220	[3]
Interest Rate	4.74%
Secured Debt [Member] | February 2013 [Member] | December 2030 [Member]
Debt Instrument [Line Items]
Secured debt issuances	203	[3],[4]
Interest Rate	2.043%
Percentage of debt hedged by interest rate derivatives	95.00%
Secured Debt [Member] | Bridge Loan [Member] | June 2013 [Member]
Debt Instrument [Line Items]
Payments for the redemption of long-term debt	190
First Mortgage Bonds [Member] | March 2013 [Member] | March 2043 [Member]
Debt Instrument [Line Items]
First mortgage bonds issuances	500	[5]
Interest Rate	4.10%
Duke Energy Carolinas [Member]
Debt Instrument [Line Items]
Payments for the redemption of long-term debt	0		751
Progress Energy [Member]
Debt Instrument [Line Items]
Payments for the redemption of long-term debt	736		1
Progress Energy [Member] | Corporate Debt Securities [Member]
Debt Instrument [Line Items]
Interest Rate	7.10%
Payments for the redemption of long-term debt	300
Duke Energy Progress [Member]
Debt Instrument [Line Items]
Total Issuances	500
Payments for the redemption of long-term debt	1		0
Duke Energy Progress [Member] | First Mortgage Bonds [Member] | March 2013 [Member] | March 2043 [Member]
Debt Instrument [Line Items]
First mortgage bonds issuances	500	[5]
Interest Rate	4.10%
Duke Energy Florida [Member]
Debt Instrument [Line Items]
Payments for the redemption of long-term debt	426		1
Duke Energy Ohio [Member]
Debt Instrument [Line Items]
Payments for the redemption of long-term debt	2		2
Duke Energy Ohio [Member] | First Mortgage Bonds [Member] | June 2013 [Member]
Debt Instrument [Line Items]
Interest Rate	2.10%
Duke Energy Indiana [Member]
Debt Instrument [Line Items]
Payments for the redemption of long-term debt	1		1
Parent Company [Member]
Debt Instrument [Line Items]
Total Issuances	500
Parent Company [Member] | Unsecured Debt [Member] | June 2013 [Member]
Debt Instrument [Line Items]
Interest Rate	5.65%
Parent Company [Member] | Unsecured Debt [Member] | January 2013 [Member] | January 2073 [Member]
Debt Instrument [Line Items]
Unsecured debt issuances	$ 500	[1]
Interest Rate	5.125%
Debt instrument, call date, earliest	Jan. 01, 2018

[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 our commercial paper and for general corporate purposes. See Note 11 for additional information about the QUIPS.

[2] 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.

[3] 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.

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

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