Leases - Lease Maturities (Details) $ in Millions	Jun. 30, 2019 USD ($)
Operating Leases
2019	$ 18
2020	28
2021	18
2022	12
2023	10
Thereafter	9
Total lease payments	95
Less imputed interest	(10)
Total operating lease liabilities	85
Finance Leases
2019	11
2020	22
2021	22
2022	21
2023	21
Thereafter	311
Total lease payments	408
Less imputed interest	(169)
Total finance lease liabilities	$ 239