Employee Benefits (Schedule Of Amounts Recognized In The Consolidated Balance Sheet) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Noncurrent liabilities	$ (344)	$ (365)
Defined Benefit Plans [Member] | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(2)	(2)
Noncurrent liabilities	(155)	(183)
Net amount recognized	(157)	(185)
Defined Benefit Plans [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(3)	(2)
Noncurrent liabilities	(121)	(107)
Net amount recognized	(124)	(109)
Other Postretirement Plan Benefits [Member] | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(8)	(8)
Noncurrent liabilities	(65)	(72)
Net amount recognized	(73)	(80)
Other Postretirement Plan Benefits [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	0	0
Noncurrent liabilities	(3)	(3)
Net amount recognized	$ (3)	$ (3)