Stock-Based Compensation (Summary of Stock Awards Outstanding) (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Restricted Stock Units Awards [Member]
Schedule Of Shares Awarded [Abstract]
Shares awarded (in thousands)	612		443		636
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at December 31, 2012	1,607
Granted	612		443		636
Vested	(794)
Forfeited	(25)
Outstanding at December 31, 2013	1,400		1,607
Fair value	$ 42	[1]	$ 28	[1]	$ 34	[1]
Stock awards expected to vest	1,365
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Weighted average fair value at December 31, 2012	$ 64
Granted	$ 69
Vested	$ 63
Forfeited	$ 68
Weighted average fair value at December 31, 2013	$ 66		$ 64
Weighted average fair value of awards expected to vest	$ 66
Performance Awards [Member]
Schedule Of Shares Awarded [Abstract]
Shares awarded (in thousands)	633		352		432
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at December 31, 2012	2,346
Granted	633		352		432
Vested	(858)
Forfeited	(299)
Outstanding at December 31, 2013	1,822		2,346
Fair value	$ 28		$ 19		$ 20
Stock awards expected to vest	1,646
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Weighted average fair value at December 31, 2012	$ 47
Granted	$ 45
Vested	$ 49
Forfeited	$ 46
Weighted average fair value at December 31, 2013	$ 46		$ 47
Weighted average fair value of awards expected to vest	$ 47

[1] Based on the market price of Duke Energy's common stock at the grant date.