Derivatives - Not Designated as Hedging Instruments (Details) item in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($) item	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) item	Jun. 30, 2015 USD ($)	Dec. 31, 2015 item
Net sales
Outstanding commodity derivatives contracts not designated as hedging instruments
Net gains (losses) from derivatives not designated as hedging instruments recognized in net sales (in dollars) | $	$ 38	$ 45	$ 26	$ (44)
Oil (in barrels) | Long position
Outstanding commodity derivatives contracts not designated as hedging instruments
Net Outstanding Position	149		149		83
Natural Gas (in cubic feet) | Short position
Outstanding commodity derivatives contracts not designated as hedging instruments
Net Outstanding Position	71,000		71,000		58,000
Carbon dioxide (in cubic feet) | Long position
Outstanding commodity derivatives contracts not designated as hedging instruments
Net Outstanding Position	571,000		571,000		603,000