Postretirement Plans (Schedule Of Amounts Recognized In Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss/(gain)	$ 22,061	$ 22,942
Prior service (credits)	(1,546)	(1,211)
Total recognized in Accumulated other comprehensive loss	20,515	21,731
Other Postretirement Benefits Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss/(gain)	(783)	(59)
Prior service (credits)	(158)	(226)
Total recognized in Accumulated other comprehensive loss	$ (941)	$ (285)