Derivatives (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013 Oil (in barrels) bbl	Dec. 31, 2012 Oil (in barrels) bbl	Mar. 31, 2013 Natural Gas (in cubic feet) ft3	Dec. 31, 2012 Natural Gas (in cubic feet) ft3	Mar. 31, 2013 Precious metals (in troy ounces) ozt	Dec. 31, 2012 Precious metals (in troy ounces) ozt
Outstanding commodity derivatives contracts not designated as hedging instruments
Net Outstanding Position Long/(Short)			(17,000,000)	(17,000,000)	(161,000,000,000)	(217,000,000,000)	1,000,000	1,000,000
Net Gains from derivatives not designated as hedging instruments recognized in net sales. (in dollars)	$ 59	$ 52