Basis Of Presentation (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Increase in Earnings from operations due to net favorable cumulative catch-up adjustments	$ 20	$ 74	$ 184	$ 308
Increase in diluted earnings per share due to net favorable cumulative catch-up adjustments	$ 0.02	$ 0.07	$ 0.17	$ 0.27