Long-Term Debt (Schedule Of Future Minimum Lease Obligations) (Details) $ in Millions	Dec. 31, 2017 USD ($)
Finance Lease Obligations, Future Minimum Payments [Abstract]
2018	$ 9
2019	9
2020	10
2021	10
2022	10
Thereafter	52
Total future payments	100
Less: Amounts representing interest	(55)
Present value of minimum lease payments	45
Capital Lease Obligations, Future Minimum Payments [Abstract]
2018	41
2019	29
2020	19
2021	12
2022	9
Thereafter	9
Total future payments	119
Less: Amounts representing interest	(14)
Present value of minimum lease payments	$ 105

Amount of minimum lease payments for capital leases.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84164817&loc=d3e45280-112737

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Amount of minimum lease payments for capital leases due in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for capital leases due in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for capital leases due in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for capital leases due in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount necessary to reduce net minimum lease payments to present value for capital leases.

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Present value of minimum lease payments for capital leases net of executory costs, including amounts paid by the lessee to the lessor for insurance, maintenance and taxes.

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Amount necessary to reduce minimum lease payments to present value for sale-leaseback transactions accounted for using the deposit method or as a financing.

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Amount of minimum lease payments for sale-leaseback transactions accounted for using the deposit method or as a financing.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 40
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77914019&loc=d3e50824-112756

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