Goodwill And Other Intangibles (Expenses Related To Emissions And Renewable Energy Requirements) (Details) (Power [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Power [Member]
Emissions Expense	$ 5	$ 35	$ 52
Renewable Energy Expense	$ 34	$ 43	$ 50