Derivative and Hedging Activities - Derivative Instruments in Balance Sheet Table (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	$ (150)	$ (577)
Derivative Asset, Fair Value, Gross Liability	0	0
Derivative, Fair Value, Net	(150)	(577)
Not Designated as Hedging Instrument [Member] \| Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset		(504)
Derivative Liability, Fair Value, Gross Liability	(150)
Derivative Asset, Fair Value, Gross Liability	0
Derivative Liability, Fair Value, Gross Asset		0
Derivative, Fair Value, Net	(150)	(504)
Designated as Hedging Instrument [Member] \| Foreign Exchange Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability		(73)
Derivative Liability, Fair Value, Gross Asset		0
Derivative, Fair Value, Net		(73)
Other Current Assets [Member] \| Not Designated as Hedging Instrument [Member] \| Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	5	1
Derivative Asset, Fair Value, Gross Liability	(4)	(1)
Derivative, Fair Value, Net	1	0
Other Current Liabilities [Member] \| Not Designated as Hedging Instrument [Member] \| Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	(161)	(490)
Derivative Liability, Fair Value, Gross Asset	4	1
Derivative, Fair Value, Net	(157)	(489)
Other Noncurrent Assets [Member] \| Not Designated as Hedging Instrument [Member] \| Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	8
Derivative Asset, Fair Value, Gross Liability	(1)
Derivative, Fair Value, Net	7
Other Noncurrent Liabilities [Member] \| Not Designated as Hedging Instrument [Member] \| Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	(2)	(15)
Derivative Liability, Fair Value, Gross Asset	1	0
Derivative, Fair Value, Net	$ (1)	(15)
Other Noncurrent Liabilities [Member] \| Designated as Hedging Instrument [Member] \| Foreign Exchange Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability		(73)
Derivative Liability, Fair Value, Gross Asset		0
Derivative, Fair Value, Net		$ (73)

Fair value of liability associated with 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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=51825145&loc=SL20226003-175313

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Fair value, before effects of master netting arrangements, of a 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. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Fair value, before effects of master netting arrangements, of a 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. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Fair value of asset associated with 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.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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