Leases (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Leases, Rent Expense, Net [Abstract]
Lease and rental expense under operating leases	$ 193	$ 146	$ 141
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019	305
2020	236
2021	186
2022	145
2023	102
Thereafter	326
Total Minimum Payments Under Operating Leases	1,300
Capital Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019	18
2020	17
2021	12
2022	10
2023	5
Thereafter	42
Total Minimum Payments Under Capital Leases	104
Finance charge included in minimum lease payments	$ 23

Amount of minimum lease payments for capital leases.

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Amount of minimum lease payments for capital leases 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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Amount of minimum lease payments for capital leases 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 minimum lease payments for capital leases 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 minimum lease payments for capital leases 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 minimum lease payments for capital leases 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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Amounts to be paid by lessee to lessor for maintenance, insurance, and tax expenses related to the leased asset.

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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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Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income.

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