| **Restructuring and Impairments - Restructuring Liability (Details) (USD $)In Millions, unless otherwise specified** | 3 Months Ended | 9 Months Ended | 3 Months Ended | 9 Months Ended |        | 9 Months Ended |        | 9 Months Ended |        | 9 Months Ended |        |
|----------------------------------------------------------------------------------------------------------------------|----------------|----------------|----------------|----------------|--------|----------------|--------|----------------|--------|----------------|--------|
||
| **Restructuring Cost and Reserve [Line Items]**                                                                      |           |           |           |           |   |           |   |           |   |           |   |   |   |   |   |   |   |   |
| Restructuring Charges                                                                                                | $ 16           | $ 6            | $ 27           | $ 14           | $ 8    | $ 11           |   |           |   |           |   |   |   |   |   |   |   |   |
| Restructuring liability at beginning of year                                                                         |           | 36             | 34             | 89             |   |           | 15     | 72             | 16     | 0              | 0      | 0 | 18 | 17 | 19 | 1 | 0 | 1 |
| Additions                                                                                                            |           |           | 14             | 17             |   |           | 12     | 3              |   | 1              | 3      |   | 1 | 6 |   | 0 | 5 |   |
| Payments                                                                                                             |           |           | (21)           | (67)           |   |           | (12)   | (54)           |   | (1)            | (3)    |   | (6) | (6) |   | (2) | (4) |   |
| Adjustments                                                                                                          |           |           | (2)            | (3)            |   |           | (2)    | (5)            |   | 0              | 0      |   | 0 | 2 |   | 0 | 0 |   |
| Restructuring liability at end of year                                                                               | $ 25           |           | $ 25           |           |   | $ 15           | $ 13   |           | $ 16   | $ 0            |   | $ 0 | $ 13 |   | $ 19 | $ (1) |   | $ 1 |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.
+ References
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Discloses the amount charged against the accrued restructuring reserves, or earnings if not previously accrued, during the period for the specified type of 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.
+ References
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| X                                                                                                                                                                        |
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.
+ References
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of any reversal and other adjustment made during the period to the amount of a previously accrued liability for a specified type of restructuring cost, excluding adjustments for costs incurred during the period, costs settled during the period, and foreign currency translation adjustments.
+ References
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