Derivatives (Details 1) item in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($) item	Sep. 30, 2014 USD ($) item	Sep. 30, 2015 USD ($) item	Sep. 30, 2014 USD ($) 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) | $				$ 12
Net losses from derivatives not designated as hedging instruments recognized in net sales (in dollars) | $	$ 119	$ 72	$ 163
CO2 (in cubic feet)
Outstanding commodity derivatives contracts not designated as hedging instruments
Net Outstanding Position Long/(Short)	607,000	621,000	607,000	621,000
Oil (in barrels)
Outstanding commodity derivatives contracts not designated as hedging instruments
Net Outstanding Position Long/(Short)	81	(9)	81	(9)
Natural Gas (in cubic feet)
Outstanding commodity derivatives contracts not designated as hedging instruments
Net Outstanding Position Long/(Short)	(54,000)	(32,000)	(54,000)	(32,000)