Leases - Future Payments (Details) $ in Millions	Dec. 31, 2019 USD ($)
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2020	$ 143
2021	129
2022	114
2023	62
2024	55
Thereafter	210
Total lease payments	713
Less: Interest	94
Present value of lease liabilities	619
Finance Lease, Liability, Payment, Due [Abstract]
2020	14
2021	12
2022	5
2023	1
2024	0
Thereafter	0
Total lease payments	32
Less: Interest	3
Present value of lease liabilities	29
Finance lease cost
2020	157
2021	141
2022	119
2023	63
2024	55
Thereafter	210
Total lease payments	745
Less: Interest	97
Present value of lease liabilities	$ 648