Price Risk Management Activities, Hedging Instruments by Consolidated Balance Sheet Location (Details) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Fair Values of Derivative Instruments
Total derivative assets, net	$ 6,774	$ 3,343
Total derivative liabilities, net	6,922	3,599
Designated as Hedging Instrument [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	410	206
Derivative liability, fair value, gross liability	280	254
Designated as Hedging Instrument [Member] \| Future [Member] \| Trade Accounts Receivable [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	360	120
Derivative liability, fair value, gross asset	237	183
Designated as Hedging Instrument [Member] \| Swap [Member] \| Trade Accounts Receivable [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	46
Derivative liability, fair value, gross asset	40
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		55
Derivative liability, fair value, gross asset		39
Designated as Hedging Instrument [Member] \| Swap [Member] \| Accrued Expenses [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross liability	4	31
Derivative liability, fair value, gross liability	3	32
Not Designated as Hedging Instrument [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	6,364	3,137
Derivative liability, fair value, gross liability	6,642	3,345
Not Designated as Hedging Instrument [Member] \| Future [Member] \| Trade Accounts Receivable [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	6,170	2,717
Derivative liability, fair value, gross asset	6,266	2,914
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 liability, fair value, gross asset	5
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	287
Derivative liability, fair value, gross asset	1	277
Not Designated as Hedging Instrument [Member] \| Swap [Member] \| Accrued Expenses [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross liability	181	116
Derivative liability, fair value, gross liability	268	148
Not Designated as Hedging Instrument [Member] \| Commodity Option [Member] \| Trade Accounts Receivable [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	5
Derivative liability, fair value, gross asset	0
Not Designated as Hedging Instrument [Member] \| Commodity Option [Member] \| Accrued Expenses [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross liability	0	0
Derivative liability, fair value, gross liability	21	6
Not Designated as Hedging Instrument [Member] \| Forward Contracts [Member] \| Inventories [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross liability	0	17
Derivative liability, fair value, gross liability	$ 81	$ 0

Fair value of liability associated with derivative asset, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position.

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