Financial Instruments, Derivatives and Hedging Activities (Details 2) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Derivatives designated as hedging instruments:
Fair value of commodity contracts
Fair value of assets	$ 37	$ 14
Fair value of liabilities	25	45
Commodity and foreign currency contracts | Derivatives designated as hedging instruments: | Accounts receivable-net
Fair value of commodity contracts
Fair value of assets	35	14
Commodity and foreign currency contracts | Derivatives designated as hedging instruments: | Accounts payable and accrued liabilities
Fair value of commodity contracts
Fair value of liabilities	16	34
Commodity contracts
Fair value of commodity contracts
Commodity futures contract (in bushels of corn and soy bean or mmbtu of gas)	101,000,000
Commodity contracts | Derivatives designated as hedging instruments: | Other non-current assets
Fair value of commodity contracts
Fair value of assets	2
Commodity contracts | Derivatives designated as hedging instruments: | Noncurrent liabilities
Fair value of commodity contracts
Fair value of liabilities	$ 9	$ 11
Natural Gas Commodity
Fair value of commodity contracts
Commodity futures contract (in bushels of corn and soy bean or mmbtu of gas)	18,000,000