Commitments and Contingencies - Future Minimum Rental Commitments (Details) $ in Millions	Dec. 31, 2018 USD ($)
Future minimum rental commitments
Rent commitment, 2019	$ 130
Rent commitment, 2020	102
Rent commitment, 2021	85
Rent commitment, 2022	75
Rent commitment, 2023	67
Rent commitment, 2024 and beyond	400
Rent commitment, Total	859
Sublease income, 2019	(17)
Sublease income, 2020	(3)
Sublease income, 2021	0
Sublease income, 2022	0
Sublease income, 2023	0
Sublease income, 2024 and beyond	0
Sublease income, Total	(20)
Net rent, 2019	113
Net rent, 2020	99
Net rent, 2021	85
Net rent, 2022	75
Net rent, 2023	67
Net rent, 2024 and beyond	400
Net rent, Total	$ 839

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Operating Leases Future Minimum Net Payments Due.

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Operating leases future minimum net payments due current.

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Operating leases future minimum net payments due in five years.

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Operating leases future minimum net payments due in four years.

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Operating leases future minimum net payments due in three years.

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Operating leases future minimum net payments due in two years.

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Operating leases future minimum net payments due thereafter.

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Operating leases future minimum sublease income due current.

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Amount of required minimum rental payments for leases having an initial or remaining non-cancelable letter-terms in excess of one year.

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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.

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Contractually required future rental payments receivable on noncancelable subleasing arrangements.

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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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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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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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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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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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