Presentation - Venezuelan Operations (Details) In Millions, unless otherwise specified					12 Months Ended
	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)	Dec. 31, 2009 USD ($)	Dec. 31, 2012 VENEZUELA USD ($)	Feb. 08, 2013 VENEZUELA VEB	Dec. 31, 2012 VENEZUELA VEB	Dec. 31, 2011 VENEZUELA USD ($)
Net monetary assets					$ 620			$ 301
Cash and cash equivalents included in net monetary assets	15,659	17,148	14,805	20,894	721			331
Foreign Currency Spot Exchange Rate						6.3	4.3
Foreign currency translation loss that would occur from a 50% change in the official bolivar exchange rate					$ 200