Leases Summary of Operating Lease Liabilities Maturity (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Operating Leases, Summary of Aggregate Future Lease Payments After Adoption of 842
2019 (remaining nine months)	$ 69
2020	84
2021	72
2022	65
2023	57
Thereafter	257
Total undiscounted lease payments	604
Less: imputed interest	(100)
Total discounted lease payments	$ 504
Operating Leases, Summary of Aggregate Future Lease Payments Before Adoption of 842
2019		$ 89
2020		78
2021		66
2022		60
2023		52
Thereafter		229
Total minimum lease payments		$ 574

Amount of lessee's undiscounted obligation for lease payments for operating lease.

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Amount of lessee's undiscounted obligation for lease payments for operating lease having an initial or remaining lease term in excess of one year due in remainder of fiscal year following latest fiscal year.

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