Leases Summary of Operating Lease Liabilities Maturity (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Operating Leases, Summary of Aggregate Future Lease Payments After Adoption of 842
2019 (remaining six months)	$ 47
2020	87
2021	83
2022	75
2023	66
Thereafter	305
Total undiscounted lease payments	663
Less: imputed interest	(109)
Total discounted lease payments	$ 554
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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