Price Risk Management Activities, Hedging Instruments by Consolidated Balance Sheet Location (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Fair Values of Derivative Instruments
Total derivative assets, net	$ 1,210	$ 537
Total derivative liabilities, net	1,316	529
Designated as Hedging Instrument [Member] \| Future [Member] \| Commodity Contract [Member] \| Trade Accounts Receivable [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	3	25
Derivative asset, fair value, gross liability	2	36
Not Designated as Hedging Instrument [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	1,207	512
Derivative liability, fair value, gross liability	1,314	493
Not Designated as Hedging Instrument [Member] \| Future [Member] \| Commodity Contract [Member] \| Trade Accounts Receivable [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	1,179	474
Derivative asset, fair value, gross liability	1,258	455
Not Designated as Hedging Instrument [Member] \| Swap [Member] \| Commodity Contract [Member] \| Trade Accounts Receivable [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	26	33
Derivative asset, fair value, gross liability	29	18
Not Designated as Hedging Instrument [Member] \| Swap [Member] \| Commodity Contract [Member] \| Accrued Liabilities [Member]
Fair Values of Derivative Instruments
Derivative liability, fair value, gross asset	2	0
Derivative liability, fair value, gross liability	3	5
Not Designated as Hedging Instrument [Member] \| Swap [Member] \| Commodity Contract [Member] \| Prepaid Expenses and Other Current Assets [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset		3
Derivative asset, fair value, gross liability		0
Not Designated as Hedging Instrument [Member] \| Forward Contracts [Member] \| Physical Purchase Contracts [Member] \| Inventories [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	0	0
Derivative asset, fair value, gross liability	11	5
Not Designated as Hedging Instrument [Member] \| Forward Contracts [Member] \| Foreign Currency Contract [Member] \| Accrued Liabilities [Member]
Fair Values of Derivative Instruments
Derivative liability, fair value, gross asset	0	0
Derivative liability, fair value, gross liability	13	8
Not Designated as Hedging Instrument [Member] \| Options Held [Member] \| Commodity Contract [Member] \| Trade Accounts Receivable [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset		2
Derivative asset, fair value, gross liability		$ 2

Fair value, after offset of derivative liability, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, before offset against an obligation to return collateral under a master netting arrangement. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

+ References+ Details

Fair value, after offset of derivative asset, of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be and before offset against a right to receive collateral under a master netting arrangement. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

+ References+ Details