Price Risk Management Activities, Hedging Instruments by Consolidated Balance Sheet Location (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Fair Values of Derivative Instruments
Total derivative assets, net	$ 3,249	$ 1,980
Total derivative liabilities, net	3,309	1,970
Designated as Hedging Instrument [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	111	300
Derivative liability, fair value, gross liability	80	286
Designated as Hedging Instrument [Member] | Future [Member] | Trade Accounts Receivable [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	67	264
Derivative asset, fair value, gross liability	40	240
Designated as Hedging Instrument [Member] | Swap [Member] | Accrued Expenses [Member]
Fair Values of Derivative Instruments
Derivative liability, fair value, gross asset	0	36
Derivative liability, fair value, gross liability	2	46
Designated as Hedging Instrument [Member] | Swap [Member] | Trade Accounts Receivable [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	44
Derivative asset, fair value, gross liability	38
Not Designated as Hedging Instrument [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	3,138	1,680
Derivative liability, fair value, gross liability	3,229	1,684
Not Designated as Hedging Instrument [Member] | Future [Member] | Trade Accounts Receivable [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	3,071	1,636
Derivative asset, fair value, gross liability	3,150	1,624
Not Designated as Hedging Instrument [Member] | Swap [Member] | Accrued Expenses [Member]
Fair Values of Derivative Instruments
Derivative liability, fair value, gross asset	48	38
Derivative liability, fair value, gross liability	62	51
Not Designated as Hedging Instrument [Member] | Swap [Member] | Trade Accounts Receivable [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	6
Derivative asset, fair value, gross liability	11
Not Designated as Hedging Instrument [Member] | Swap [Member] | Prepaid Expenses and Other Current Assets [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	2	4
Derivative asset, fair value, gross liability	1	2
Not Designated as Hedging Instrument [Member] | Commodity Option [Member] | Accrued Expenses [Member]
Fair Values of Derivative Instruments
Derivative liability, fair value, gross asset	1	0
Derivative liability, fair value, gross liability	1	2
Not Designated as Hedging Instrument [Member] | Commodity Option [Member] | Trade Accounts Receivable [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	4	2
Derivative asset, fair value, gross liability	3	0
Not Designated as Hedging Instrument [Member] | Forward Contracts [Member] | Inventories [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	3	0
Derivative asset, fair value, gross liability	0	2
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Accrued Expenses [Member]
Fair Values of Derivative Instruments
Derivative liability, fair value, gross asset	0	0
Derivative liability, fair value, gross liability	1	3
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Trade Accounts Receivable [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	3
Derivative liability, fair value, gross asset	$ 0