Employee Benefits (Schedule Of Accumulated Benefit Obligations In Excess Of Plan Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 486	$ 650
Domestic Plan [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0	$ 0
Defined Benefit Plan, Plan Assets, Contributions by Employer	8	9
Domestic Plan [Member] | Defined Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	486	650	614
Defined Benefit Plan, Plan Assets, Contributions by Employer	3	2
Domestic Plan [Member] | Defined Benefit Plans [Member] | Underfunded Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Pension Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Projected Benefit Obligation	(648)	(807)
Accumulated benefit obligation	(648)	(807)
Fair value of plan assets	486	650
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	17	18
Foreign Plan [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0	0
Defined Benefit Plan, Plan Assets, Contributions by Employer	0	0
Foreign Plan [Member] | Defined Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	17	18	$ 16
Defined Benefit Plan, Plan Assets, Contributions by Employer	1	1
Foreign Plan [Member] | Defined Benefit Plans [Member] | Underfunded Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Pension Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Projected Benefit Obligation	(128)	(128)
Accumulated benefit obligation	(125)	(126)
Fair value of plan assets	$ 10	$ 5