Derivatives (Details 1) item in Millions, $ in Millions	6 Months Ended
	Jun. 30, 2015 USD ($) item	Jun. 30, 2014 USD ($) item
Net sales
Outstanding commodity derivatives contracts not designated as hedging instruments
Net gains from derivatives not designated as hedging instruments recognized in net sales (in dollars) | $		$ 84
Net losses from derivatives not designated as hedging instruments recognized in net sales (in dollars) | $	$ 44
CO2 (in cubic feet)
Outstanding commodity derivatives contracts not designated as hedging instruments
Net Outstanding Position Long/(Short)	612,000	621,000
Oil (in barrels)
Outstanding commodity derivatives contracts not designated as hedging instruments
Net Outstanding Position Long/(Short)	76	(9)
Natural Gas (in cubic feet)
Outstanding commodity derivatives contracts not designated as hedging instruments
Net Outstanding Position Long/(Short)	(33,000)	(32,000)