| **Leases (Minimum Lease Payments) (Details) $ in Millions** | Dec. 31, 2018 USD ($) |
|-------------------------------------------------------------|-----------------------|
| **Leases [Abstract]**                                       |                  |
| 2019                                                        | $ 35                  |
| 2020                                                        | 39                    |
| 2021                                                        | 41                    |
| 2022                                                        | 38                    |
| 2023                                                        | 32                    |
| Thereafter                                                  | 200                   |
| Total                                                       | $ 385                 |

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| - Definition
Amount of required minimum rental payments for leases having an initial or remaining non-cancelable letter-terms in excess of one year.
+ References
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| - Definition
Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.
+ References
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| - Definition
Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.
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| - Definition
Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.
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| - Definition
Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.
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| - Definition
Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.
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| - Definition
Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.
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