| **Fair Value Measurements - Level 3 Reconciliation (Details) (USD $)In Millions, unless otherwise specified**             | 12 Months Ended |     |        |
|---------------------------------------------------------------------------------------------------------------------------|-----------------|-----|--------|
||
| Guarantees [Member]                                                                                                       |            |     |   |  |   |   |
| **Fair Value Assets And Liablities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]**           |            |     |   |  |   |   |
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset (Liability) Beginning Value       |            |     |   |  | $ (6) | $ 0 |
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings | 0               | [1] | 0      | [1] |   |   |
| Fair Value, Level 3 Transfers out, Description                                                                            | 0               |     | 0      |  |   |   |
| Issuances                                                                                                                 | (1)             |     | (6)    |  |   |   |
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements                      | 0               |     | 0      |  |   |   |
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset (Liability) Ending Value          | (7)             |     | (6)    |  |   |   |
| Change in unrealized gains on assets and liabilities still held                                                           | 0               |     | 0      |  |   |   |
| Retained Interest [Member]                                                                                                |            |     |   |  |   |   |
| **Fair Value Assets And Liablities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]**           |            |     |   |  |   |   |
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset (Liability) Beginning Value       |            |     |   |  | 0 | 53 |
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings | 0               | [1] | 0      | [1] |   |   |
| Fair Value, Level 3 Transfers out, Description                                                                            | 0               |     | 0      |  |   |   |
| Issuances                                                                                                                 | 0               |     | 0      |  |   |   |
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements                      | 0               |     | 53     |  |   |   |
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset (Liability) Ending Value          | 0               |     | 0      |  |   |   |
| Change in unrealized gains on assets and liabilities still held                                                           | 0               |     | 0      |  |   |   |
| Commodity Contract [Member]                                                                                               |            |     |   |  |   |   |
| **Fair Value Assets And Liablities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]**           |            |     |   |  |   |   |
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset (Liability) Beginning Value       |            |     |   |  | (2) | 2 |
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings | 0               | [1] | 2      | [1] |   |   |
| Fair Value, Level 3 Transfers out, Description                                                                            | 2               |     | 0      |  |   |   |
| Issuances                                                                                                                 | 0               |     | 0      |  |   |   |
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements                      | 0               |     | 6      |  |   |   |
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset (Liability) Ending Value          | 0               |     | (2)    |  |   |   |
| Change in unrealized gains on assets and liabilities still held                                                           | $ 0             |     | $ (2)  |  |   |   |
|                                                                                                                           |
| [1]For commodity contracts, gains are included in Cost of products sold.                                                  |

| X                                                                                                                                                                                                                        |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                                                                                                                                                                           |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Fair Value Change in Unrealized Gains on Assets and Liabilities Still Held
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                      |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
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+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset (Liability) Ending Value
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                               |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Issuances
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Disclosures concerning the reasons for transfers out of Level 3 of the fair value hierarchy.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(3) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of gain (loss) recognized in earnings, arising from assets measured at fair value on a recurring basis using unobservable inputs (level 3).
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Settlements that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258
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