Stock-Based Compensation (Stock Options) (Details) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Stock Option Activity, Options [Roll Forward]
Outstanding at December 31, 2012	1,654
Granted	310		340	358
Exercised	(1,162)
Forfeited or expired	(9)
Outstanding at December 31, 2013	793		1,654
Exercisable at December 31, 2013	137
Options expected to vest	656
Stock Option Activity, Weighted Average Exercise Price [Roll Forward]
Weighted average exercise price of options outstanding at December 31, 2012	$ 51
Granted	$ 69
Exercised	$ 48
Forfeited or expired	$ 41
Weighted average exercise price of options outstanding at December 31, 2013	$ 61		$ 51
Weighted average exercise price of options exercisable at December 31, 2013	$ 46
Weighted average exercise price of options expected to vest	$ 64
Weighted-Average Remaining Life [Abstract]
Weighted average remaining life of options outstanding at December 31, 2013, years	7 years 3 months 0 days
Weighted average remaining life of options exercisable at December 31, 2013, years	1 year 5 months 0 days
Weighted average remaining life of options expected to vest, years	8 years 5 months 0 days
Aggregate Intrinsic Value [Abstract]
Aggregate intrinsic value of options outstanding at December 31, 2013	$ 6
Aggregate intrinsic value of options exercisable at December 31, 2013	3
Aggregate intrinsic value of options expected to vest	3
Schedule Of Information Related To Stock Options [Abstract]
Intrinsic value of options exercised	26		17	26
Tax benefit resulting from options exercised	10		7	10
Cash received from options exercised	$ 9		$ 21	$ 74
Stock options granted	310		340	358
Weighted-Average Assumptions for Option Pricing [Abstract]
Risk-free interest rate	1.00%	[1]
Expected dividend yield	4.70%	[2]
Expected life, years	6 years 0 months 0 days	[3]
Expected volatility	18.10%	[4]

[1] The risk-free rate is based upon the average of five-year and seven-year U.S. Treasury Constant Maturity rates as of the grant date.

[2] The expected dividend yield is based upon the most recent annualized dividend and the one-year average closing stock price.

[3] The expected life of options is derived from the simplified method approach.

[4] Volatility is based equally between historical and implied volatility. Historic volatility is based on Duke Energy's historical volatility over the expected life using daily stock prices. Implied volatility is the average for all option contracts with a term greater than six months using the strike price closest to the stock price on the valuation date.