Leases (Maturity of Lease Liabilities) (Details) $ in Millions	Sep. 30, 2019 USD ($)
Operating leases
2019	$ 53
2020	199
2021	170
2022	130
2023	96
Thereafter	137
Total lease payments	785
Less amount representing interest	(89)
Present value of lease liabilities	696
Finance leases
2019	12
2020	42
2021	42
2022	18
2023	6
Thereafter	7
Total lease payments	127
Less amount representing interest	(7)
Present value of lease liabilities	$ 120