| **Fair Value Measurements Narrative (Details) (USD $)In Millions, unless otherwise specified**   | 3 Months Ended | 9 Months Ended | 3 Months Ended | 9 Months Ended |        | 3 Months Ended | 9 Months Ended |
|--------------------------------------------------------------------------------------------------|----------------|----------------|----------------|----------------|--------|----------------|----------------|
||
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |           |           |           |           |   |           |           |   |   |   |   |   |
| Cash and Cash Equivalents, Maturity Term                                                         |           |           | 90 days        |           |   |           |           |   |   |   |   |   |
| Marketable Securities, Maturity Term                                                             |           |           | 90 days        |           |   |           |           |   |   |   |   |   |
| Goodwill, Impairment Loss                                                                        |           |           |           |           |   |           |           | $ 0 | $ 142 | $ 0 | $ 142 | $ 0 |
| Indefinite-Lived Intangible Assets (Excluding Goodwill)                                          |           |           |           |           |   |           |           |   | 43 |   |   |   |
| Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)                           |           |           |           |           |   |           |           | 0 | 7 | 0 | 7 | 0 |
| Other Assets                                                                                     |           |           |           |           |   |           | 18             |   |   |   |   |   |
| Asset impairment charges                                                                         | $ 4            | $ 17           | $ 173          | $ 17           | $ 18   | $ 19           |           |   | $ 149 |   |   |   |

| X                                                                                                                                                                                                                                                                                   |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Maximum maturity term for a cash and cash equivalent instrument
+ References
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| X                                                                                                                                                                                                                                                                            |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Maximum maturity term for a marketable security instrument
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.
+ References
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| X                                                                                                                                                                                                                 |
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.
+ References
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of impairment loss resulting from write-down of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.
+ References
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The aggregate carrying amounts, as of the balance sheet date, of assets not separately disclosed in the balance sheet.
+ References
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