| **Income Taxes - Income Tax (Details) (USD $)In Millions, unless otherwise specified** | 3 Months Ended | 6 Months Ended |
|----------------------------------------------------------------------------------------|----------------|----------------|
||
| **Income Taxes [Line Items]**                                                          |           |           |   |
| Valuation Allowance, Deferred Tax Asset, Change in Amount                              |           | $ (181)        |   |
| Income Taxes Percent Likelihood Of Being Realized Upon Settlement                      | 50.00%         |           | 50.00% |
| Unrecognized Tax Benefits                                                              | 84             |           | 84 |
| Unrecognized Tax Benefits that Would Not Impact Effective Tax Rate                     | 78             |           | 78 |
| Tax Adjustments, Settlements, and Unusual Provisions                                   | $ 2            |           | $ 6 |
| Liability for Uncertain Tax Benefits Time Range                                        |           |           | 12 months |

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| - Definition
Income Taxes Percent Likelihood Of Being Realized Upon Settlement
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| X                                                                                                                                                                                                                                                                          |
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| - Definition
Liability for Uncertain Tax Benefits Time Range
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| - Definition
Unrecognized Tax Benefits that Would Not Impact Effective Tax Rate
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| - Definition
Reflects the effects of adjustments of previously recorded tax expense, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, IRS tax settlement and unusual repatriation of foreign earnings.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Interpretation (FIN) -Number 48 -Paragraph 10A, 10B, 10C -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.  This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Interpretation (FIN) -Number 48 -Paragraph 10 -Subparagraph b -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.  This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.
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| - Definition
The gross amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns as of the balance sheet date.
+ References
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of the change in the period in the valuation allowance for a specified deferred tax asset.
+ References
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