Stock-Based Compensation (Stock Option Activity) (Details) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at December 31, 2011	2,089
Progress Energy transfers in	94	[1]
Granted	340		358	368
Exercised	(580)
Forfeited or expired	(289)
Outstanding at December 31, 2012	1,654		2,089
Exercisable at December 31, 2012	953		1,000	4,000
Options expected to vest	701
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Weighted average exercise price of options outstanding at December 31, 2011	$ 46
Progress Energy transfers in	$ 50
Granted	$ 63
Exercised	$ 36
Forfeited or expired	$ 65
Weighted average exercise price of options outstanding at December 31, 2012	$ 51		$ 46
Weighted average exercise price of options exercisable at December 31, 2012	$ 45		$ 45	$ 51
Weighted average exercise price of options expected to vest	$ 58
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average remaining life of options outstanding at December 31, 2012, years	6 years 4 months 0 days
Weighted average remaining life of options exercisable at December 31, 2012, years	4 years 10 months 0 days
Weighted average remaining life of options expected to vest, years	8 years 6 months 0 days
Aggregate intrinsic value of options outstanding at December 31, 2012	$ 22
Aggregate intrinsic value of options exercisable at December 31, 2012	17
Aggregate intrinsic value of options expected to vest	$ 4

[1] Progress Energy had an insignificant number of stock options outstanding as of and for the years ended December 31, 2011 and 2010.