Leases - Schedule of Operating and Finance Lease Maturities (Details) $ in Millions	Jun. 30, 2019 USD ($)
Operating Leases
Remainder of 2019	$ 122
2020	190
2021	116
2022	81
2023	61
Thereafter	170
Total lease payments	740
Less: Interest	(61)
Present value of lease liabilities	679
Finance Leases
Remainder of 2019	6
2020	12
2021	1
2022	0
2023	0
Thereafter	0
Total lease payments	19
Less: Interest	(1)
Present value of lease liabilities	18
Total
Remainder of 2019	128
2020	202
2021	117
2022	81
2023	61
Thereafter	170
Total lease payments	759
Less: Interest	(62)
Present value of lease liabilities	$ 697
Weighted average lease term, operating lease	5 years 6 months
Weighted average discount rate, operating lease	3.03%
Weighted average lease term, finance lease	1 year 9 months 18 days
Weighted average discount rate, finance lease	2.93%