Equity (Details) (USD $)	1 Months Ended	9 Months Ended
	Nov. 02, 2011	Sep. 24, 2010	Oct. 11, 2011	Sep. 30, 2011
Equity (Textuals)
Additional amount of shares authorized to be repurchased				1,000,000,000
Remaining value under share repurchase program				$ 1,292,000,000
Repurchase of additional outstanding shares				1,500,000,000
Number of common shares repurchased	1,261,766
Average price per share of repurchased shares	$ 65.12
Treasury stock purchased	$ 82,000,000	$ (469,000,000)		$ (800,000,000)
Cash dividend, declared per share			$ 0.45