Leases - Maturities (Details) $ in Millions	Jun. 30, 2019 USD ($)
Leases [Abstract]
Operating Leases, Remainder of 2019	$ 25
Operating Leases, 2020	46
Operating Leases, 2021	38
Operating Leases, 2022	29
Operating Leases, 2023	21
Operating Leases, Thereafter	57
Operating Leases, Total lease payments	216
Operating Leases, Less: interest	33
Operating Leases, Present value of lease liabilities	183
Finance Leases, Remainder of 2019	3
Finance Leases, 2020	5
Finance Leases, 2021	5
Finance Leases, 2022	4
Finance Leases, 2023	4
Finance Leases, Thereafter	15
Finance Leases, Total lease payments	36
Finance Leases, Less: interest	5
Finance Leases, Present value of lease liabilities	$ 31