Retirement Benefits (Schedule Of Accumulated And Projected Benefit Obligations) (Details) - DB Pension Plans - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
PBO	$ 2,512	$ 2,780	$ 2,562
ABO	2,200	2,400
Fair value of plan assets	2,247	2,305	$ 2,101
Pension Plan A
Defined Benefit Plan Disclosure [Line Items]
PBO	1,363	1,511
ABO	1,091	1,164
Fair value of plan assets	$ 1,059	$ 893