Stockholders' Equity (Details) (USD $) Share data in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2011
Stockholders Equity Details [Abstract]
Treasury Stock Amount Of Repurchase Authorization	$ 5,000,000,000	$ 5,000,000,000
Shares repurchased in current quarter	300,000,000	307,000,000
Shares repurchased in current quarter, shares	12
Shares repurchased to date under authorized plan		78
Cost of shares repurchased to date under authorized plan	$ 3,222,000,000	$ 3,222,000,000