Consolidated Statements of Income (Parentheticals) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenue taxes (in Dollars) (in Dollars)	$ 86	$ 9	$ 0

The excise taxes collected by a public utility and reported in revenues including 1 percent of such total the company keeps as revenue.

No definition available.