Derivatives - Outstanding Commodity Derivative Contracts (Details) - Not designated as hedging instruments item in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016 USD ($) item	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) item	Sep. 30, 2015 USD ($)	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) | $	$ 9	$ (119)	$ 35	$ (163)
Oil (in barrels) | Long position
Outstanding commodity derivatives contracts not designated as hedging instruments
Net Outstanding Position	44		44		83
Natural gas (in cubic feet) | Short position
Outstanding commodity derivatives contracts not designated as hedging instruments
Net Outstanding Position	49,000		49,000		5,000
Carbon dioxide (in cubic feet) | Long position
Outstanding commodity derivatives contracts not designated as hedging instruments
Net Outstanding Position	555,000		555,000		603,000