| **Income Taxes - Schedule of Gross Unrecognized Tax Benefits (Details) (USD $)In Millions, unless otherwise specified** | 12 Months Ended |
|-------------------------------------------------------------------------------------------------------------------------|-----------------|
||
| **Total Gross Unrecognized Tax Benefits**                                                                               |            |   |   |
| Unrecognized tax benefits at beginning of period                                                                        | $ 267           | $ 379 | $ 438 |
| Increase (decrease) in prior year tax positions                                                                         | 18              |   | 7 |
| Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions                                           |            | (23) |   |
| Increase in current year tax positions                                                                                  | 45              | 7 | 19 |
| Decrease related to settlements with taxing authorities                                                                 | (19)            | (43) | (4) |
| Decrease related to lapse of statute of limitations                                                                     | (27)            | (47) | (76) |
| Decrease due to effects of foreign currency translation                                                                 | (2)             | (6) | (5) |
| Unrecognized tax benefits at end of period                                                                              | 282             | 267 | 379 |
| Gross Unrecognized Tax Benefits, Excluding Interest and Penalties                                                       |            |   |   |
| **Total Gross Unrecognized Tax Benefits**                                                                               |            |   |   |
| Unrecognized tax benefits at beginning of period                                                                        | 196             | 283 | 324 |
| Increase (decrease) in prior year tax positions                                                                         | 20              |   | (5) |
| Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions                                           |            | (18) |   |
| Increase in current year tax positions                                                                                  | 44              | 6 | 8 |
| Decrease related to settlements with taxing authorities                                                                 | (15)            | (34) | (3) |
| Decrease related to lapse of statute of limitations                                                                     | (17)            | (38) | (38) |
| Decrease due to effects of foreign currency translation                                                                 | 0               | (3) | (3) |
| Unrecognized tax benefits at end of period                                                                              | 228             | 196 | 283 |
| Interest and Penalties                                                                                                  |            |   |   |
| **Total Gross Unrecognized Tax Benefits**                                                                               |            |   |   |
| Unrecognized tax benefits at beginning of period                                                                        | 71              | 96 | 114 |
| Increase (decrease) in prior year tax positions                                                                         | (2)             |   | 12 |
| Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions                                           |            | (5) |   |
| Increase in current year tax positions                                                                                  | 1               | 1 | 11 |
| Decrease related to settlements with taxing authorities                                                                 | (4)             | (9) | (1) |
| Decrease related to lapse of statute of limitations                                                                     | (10)            | (9) | (38) |
| Decrease due to effects of foreign currency translation                                                                 | (2)             | (3) | (2) |
| Unrecognized tax benefits at end of period                                                                              | $ 54            | $ 71 | $ 96 |

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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns.
+ References
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| - Definition
Amount of decrease in unrecognized tax benefits resulting from foreign currency translation.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
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| - Definition
Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.
+ References
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| - Definition
Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.
+ References
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