Leases (Maturity of Lease Liabilities) (Details) $ in Millions	Dec. 31, 2019 USD ($)
Operating leases
2020	$ 206
2021	180
2022	141
2023	107
2024	73
Thereafter	91
Total lease payments	798
Less amount representing interest	(87)
Present value of lease liabilities	711
Finance leases
2020	60
2021	33
2022	24
2023	12
2024	1
Thereafter	6
Total lease payments	136
Less amount representing interest	(9)
Present value of lease liabilities	$ 127