Leases Lessor (Details) $ in Millions		3 Months Ended			6 Months Ended
		Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	[1]	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	[1]
Lessor, Lease, Description [Line Items]
Operating Leases, Income Statement, Lease Revenue		$ 132	$ 91		$ 268	$ 178
Lessor, Operating Lease, Term of Contract		10 years			10 years
Number Of Contract Renewals					2
Lessor, Operating Lease, Renewal Term		5 years			5 years
2019	[2]	$ 268			$ 268
2020	[2]	535			535
2021	[2]	533			533
2022	[2]	533			533
2023	[2]	532			532
2024 and thereafter	[2]	6,292			6,292
Total Minimum Lease Revenue	[2]	$ 8,693			$ 8,693

[1] Adjusted to include the historical results of the Predecessors. See Note 1 for further discussion.

[2] Includes minimum future lease revenue assuming all renewal option periods for each agreement are exercised.