Earning Per Share (Current Stock Repurchase Program) (Details) (USD $) In Millions, except Share data			9 Months Ended
	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2011 Stock Repurchase Program [Member]
Shares as of December 31, 2010	58,562,543	36,555,242	11,400,000
Cost as of December 31, 2010	$ 1,784	$ 1,107	$ 295
Average price as of December 31, 2010			$ 25.78
Shares repurchased under stock repurchase program			22,000,000
Aggregate cost paid for shares repurchased			677
Average cost price paid per share for shares repurchased			$ 30.74
Shares as of September 30, 2011	58,562,543	36,555,242	33,400,000
Cost as of September 30, 2011	$ 1,784	$ 1,107	$ 972
Average price as of September 30, 2011			$ 29.05