| **Restructuring and Impairments - Narrative (Details) (USD $)In Millions, unless otherwise specified** | 3 Months Ended | 12 Months Ended | 3 Months Ended | 9 Months Ended |
|--------------------------------------------------------------------------------------------------------|----------------|-----------------|----------------|----------------|
||
| **Restructuring Cost and Reserve [Line Items]**                                                        |           |            |           |           |   |   |   |   |   |   |   |   |
| Asset impairment charges                                                                               | $ 18           | $ 0             | $ 18           |           |   |   |   |   |   |   |   | $ 17 |
| Restructuring charges                                                                                  | 3              | 2               |           | 13             | 8 | 12 | 1 | 2 | 11 |   |   |   |
| Restructuring and Related Cost, Expected Cost                                                          |           |            |           |           |   |   |   |   |   | $ 20 | $ 70 |   |

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| - 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.
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount expected to be recognized in earnings for the specified restructuring cost.
+ References
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| - Definition
Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.
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