Leases (Maturity Analysis For Operating and Finance Lease) (Details) $ in Millions	Jun. 30, 2019 USD ($)
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2019 (remaining six months)	$ 23
2020	42
2021	37
2022	34
2023	32
Thereafter	104
Total lease payments	272
Less: imputed interest	(68)
Present value of lease liabilities	204
Finance Lease, Liability, Payment, Due [Abstract]
2019 (remaining six months)	20
2020	33
2021	28
2022	23
2023	20
Thereafter	104
Total lease payments	228
Less: imputed interest	(69)
Present value of lease liabilities	$ 159