Leases (Maturity Analysis For Operating and Finance Lease) (Details) $ in Millions	Sep. 30, 2019 USD ($)
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2019 (remaining three months)	$ 12
2020	44
2021	38
2022	36
2023	33
Thereafter	106
Total lease payments	269
Less: imputed interest	(66)
Present value of lease liabilities	203
Finance Lease, Liability, Payment, Due [Abstract]
2019 (remaining three months)	11
2020	35
2021	31
2022	26
2023	22
Thereafter	104
Total lease payments	229
Less: imputed interest	(68)
Present value of lease liabilities	$ 161