Leases (Supplemental Balance Sheet Information Related To Leases) (Details) $ in Millions	Jun. 30, 2019 USD ($)
Supplemental Balance Sheet Information Related To Leases [Line Items]
Operating right-of-use assets	$ 198
Finance right-of-use assets	165
Operating lease liabilities	204
Finance lease liabilities	$ 159
Operating leases, Weighted-average remaining lease term	7 years 9 months 18 days
Operating leases, Weighted-average discount rate	8.29%
Weighted-average remaining lease term	9 years 1 month 6 days
Finance lease, Weighted-average discount rate	7.98%
Other Current Liabilities [Member]
Supplemental Balance Sheet Information Related To Leases [Line Items]
Finance lease liabilities, Current	$ 28
Current operating lease liabilities	44
Other Noncurrent Liabilities [Member]
Supplemental Balance Sheet Information Related To Leases [Line Items]
Financed lease liabilities, Noncurrent	131
Noncurrent operating lease liabilities	$ 160