Leases (Supplemental Cash Flow Information And Other Information For Leases) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019 USD ($)
Leases [Abstract]
Operating cash flows for operating leases	$ 18
Operating cash flows for finance leases	4
Financing cash flows for finance leases	25
ROU assets obtained in exchange for lease obligations: Operating leases	8
ROU assets obtained in exchange for lease obligations: Finance leases	$ 39
Weighted Average Remaining Lease Term (in years): Operating leases	10 years 8 months 12 days
Weighted Average Remaining Lease Term (in years): Finance leases	3 years 5 months 8 days
Weighted Average Discount Rate: Operating leases	5.54%
Weighted Average Discount Rate: Finance leases	3.84%