Long-term Debt (Details 1) (USD $)	3 Months Ended															9 Months Ended
	Mar. 31, 2011	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2011 4.50% Guaranteed Notes due 2014 [Member]	Sep. 30, 2011 2.75% Guaranteed Notes due 2015 [Member]	Sep. 30, 2011 4.20% Guaranteed Notes due 2021 [Member]	Mar. 31, 2011 4.20% Guaranteed Notes due 2021 [Member]	Sep. 30, 2011 5.25% Guaranteed Notes due 2013 [Member]	Sep. 30, 2011 2.65% Guaranteed Notes due 2016 [Member]	Mar. 31, 2011 2.65% Guaranteed Notes due 2016 [Member]	Sep. 30, 2011 3.00% Guaranteed Notes due 2013 [Member]	Sep. 30, 2009 3.00% Guaranteed Notes due 2013 [Member]	Sep. 30, 2011 9.75% Senior Notes due 2019 [Member]	Sep. 30, 2011 8.625% Senior Notes due 2014 [Member]	Sep. 30, 2011 6.00% Senior Notes due 2016 [Member]	Sep. 30, 2011 1.95% Senior Notes due 2016 [Member]	Sep. 30, 2011 3.30% Senior Notes due 2021 [Member]	Sep. 30, 2011 Floating Rate Senior Notes due 2014 [Member]	Sep. 30, 2011 Commercial Paper [Member]	Dec. 31, 2010 Commercial Paper [Member]	Sep. 30, 2011 Commercial paper programs maturing December 2011 [Member]	Sep. 30, 2011 Commercial paper programs maturing July 2016 [Member]
Long-term Debt Additional (Textual) [Abstract]
Guaranteed notes face amount							$ 1,100,000,000			$ 500,000,000		$ 450,000,000
Debt instrument interest rate				4.50%	2.75%	4.20%		5.25%	2.65%		3.00%		9.75%	8.625%	6.00%
Effective interest rate on euro denominated debt										2.39%
Committed facilities which support commercial paper programs		5,600,000,000																	5,000,000,000		2,000,000,000	3,000,000,000
Commercial paper borrowings		2,395,000,000	2,214,000,000																2,000,000,000	1,900,000,000
face amount of debt instrument																1,100,000,000	1,600,000,000	300,000,000
Basis Point over LIBOR																		0.50%
Long-term Debt (Textual) [Abstract]
Repurchase of senior notes	1,260,000,000
Long-term debt, fair value		9,000,000,000	5,600,000,000
Committed debt facility agreement aggregated		5,600,000,000																	5,000,000,000		2,000,000,000	3,000,000,000
Unused debt facility		$ 3,400,000,000