Debt and Credit Facilities (Schedule of Line of Credit Facilities) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
Line of Credit Facility [Line Items]
Facility size	$ 6,000
Line of credit facility, affiliated borrower	The Subsidiary Registrants, excluding Progress Energy each have borrowing capacity under the master credit facility up to specified sublimits for each borrower. Duke Energy has the unilateral ability at any time to increase or decrease the borrowing sublimits of each borrower, subject to a maximum sublimit for each borrower.
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility size	6,000	[1]
Notes payable and commercial paper	(1,308)	[2]
Outstanding letters of credit	(63)
Tax exempt bonds	(240)
Available capacity	4,389
Parent Company [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility size	2,250	[1]
Notes payable and commercial paper	(858)	[2]
Outstanding letters of credit	(56)
Available capacity	1,336
Parent Company [Member] | Proceeds Loaned To Subsidiary Registrants [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Notes payable and commercial paper	(450)
Duke Energy Carolinas [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility size	1,000	[1]
Notes payable and commercial paper	(300)	[2]
Outstanding letters of credit	(4)
Tax exempt bonds	(75)
Available capacity	621
Duke Energy Progress [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility size	750	[1]
Outstanding letters of credit	(2)
Available capacity	748
Duke Energy Florida [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility size	650	[1]
Outstanding letters of credit	(1)
Available capacity	649
Duke Energy Ohio [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility size	650	[1]
Tax exempt bonds	(84)
Available capacity	566
Duke Energy Indiana [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility size	700	[1]
Notes payable and commercial paper	(150)	[2]
Tax exempt bonds	(81)
Available capacity	$ 469

[1] Represents the sublimit of each borrower at March 31, 2014.

[2] Duke Energy issued $450 million of commercial paper and loaned the proceeds through the money pool to Duke Energy Carolinas and Duke Energy Indiana. The balances are classified as long-term borrowings within Long-term Debt in Duke Energy Carolinas' and Duke Energy Indiana’s Condensed Consolidated Balance Sheets.