Retirement Plans (Schedule Of Amounts Recognized In Balance Sheet) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Non-current liability	$ (1,762)	$ (1,939)
Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Non-current asset	0	0
Current liability	(27)	(30)
Non-current liability	(1,705)	(1,866)
Amounts recognized in the consolidated balance sheet	(1,732)	(1,896)
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Non-current asset	5	5
Current liability	(2)	(3)
Non-current liability	(57)	(73)
Amounts recognized in the consolidated balance sheet	$ (54)	$ (71)